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    • 专利摘要:
    The present invention relates to a resistance spot welding method including: a pulsation process of securing a steel plate assembly of two or more overlapping steel plates including at least one high strength steel plate using a pair. welding electrodes that are connected to a spot welding power source using a direct current reversal method, and perform various current-pass and current-pass interrupt repetitions while pressing the steel plates with welding electrodes; and a continuous current-passing process in which, after the pulsing process, the current is continuously passed for a longer period of time than the maximum pulsing process current-passing time, while pressing the steel plates with the welding electrodes.
    公开号:BR112016000058B1
    申请号:R112016000058-7
    申请日:2014-06-26
    公开日:2019-11-12
    发明作者:Oikawa Hatsuhiko；Fujimoto Hiroki；Yamanaka Shintaro
    申请人:Nippon Steel & Sumitomo Metal Corp；Nippon Steel Corp；
    IPC主号:
    专利说明:

    Descriptive Report of the Invention Patent for WELDING POINT METHOD FOR RESISTANCE.
    Technical field [001] The present invention relates to a resistance spot welding method.
    Background [002] Automobile chassis are assembled mainly by joining pressed steel sheets using spot welding. In spot welding used in vehicle chassis assembly, there are demands both to guarantee a nugget diameter according to the thickness of the plate, and to suppress the occurrence of sparks.
    [003] Sparks include internal spark (a phenomenon in which the base metal that has been melted by welding is diffused from the overlapping faces of steel sheets) and surface spark (a phenomenon in which the base metal that has been melted by welding is dispersed from the contact surfaces between the steel sheet and the electrodes). In both cases, the surface quality of the vehicle chassis is impaired by the dispersion of the spark and the adhesion to the vehicle's chassis. The spark that adheres to the moving parts of a welding robot is also the cause of equipment malfunction. A sparking of the needle-shaped surface that remains on the surface of the weld in spots causes damage to the wiring harness of automobiles and the like, and therefore needs to be ground with a grinder. Consequently, there is a demand to avoid internal sparking and surface sparking, as well as ensuring a specific pattern of nugget diameter to ensure the necessary strength of the welded joint.
    [004] When assembling the vehicle chassis, sometimes the nugget diameter is smaller than the standard nugget diameter due to various disturbance factors such as electrode wear, branches
    Petition 870190081229, of 8/21/2019, p. 5/47
    2/37 tion of the chain to an existing welding point, gaps between the pressed components, etc. It is therefore often necessary, when welding on a production line so as not to allow sparking to occur, to make the appropriate current range 1.0 kA or more, or 1.5 kA or more in assessing the level of the test sample. .
    [005] Recently, there is an increasing use in the automobile assembly of resistance spot welding machines that uses a direct current inversion method instead of a single phase alternating current method. Direct current inversion methods allow the transformer to be made small, with the advantage that installation for a robot that has only a small weight carrying capacity is possible, and then direct current inversion methods are used frequently, particularly automated lines.
    [006] Direct current inversion methods have a high efficiency of heat generation due to the transmission of a direct current, without exchanging the ON and OFF current as in conventionally used single-phase alternating current methods. Consequently, there are reports of formation of nuggets of the standard or larger nugget diameter using a low current, and of broader suitable current ranges than when using a single-phase alternating current, even in the case where a material is employed smooth and thin steel sheet coated with zinc that does not readily form nuggets.
    [007] In spot welding, as illustrated in Fig. 1, resistance spot welding is often used in automobiles that use a single phase current pass in which electricity is passed only once. In Fig. 1, I on the vertical axis of the welding current, and t on the horizontal axis is time (the same applies to
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    3/37
    Fig. 2 to Fig. 7). However, the value of the current at which internal dispersion is generated by welding using a single step current pass is low with high tensile strength plates that use a direct current inversion method, and there is a significant narrowing of the range of adequate current.
    [008] Japanese Patent Application Laid-Open (JP-A) No. 2010188408 (sometimes referred to below as Document 1) describes a method for suppressing spark generation in spot welding on high strength steel plates using, as shown in Fig. 2, a two-step chain passing method in which the main chain passing is performed after the compliance between the contact faces of the steel plates has been increased using a preparatory chain pass.
    [009] JP-A No. 2003-236674 (sometimes referred to below as Document 2) describes a method for suppressing sparking in spot welding of high strength steel plates using, as illustrated in Figure 3, a chain pass method in which a preparatory chain pass is employed to increase the conformity between the contacting steel sheet faces, the chain passage is then interrupted, and then the main chain is passed.
    [0010] JP-A No. 2010-207909 (sometimes referred to below as Document 3) describes the use of a chain pass method in which, as illustrated in Fig. 4 and Fig. 5, a chain pass preparatory current is used to increase the conformity between the faces of the contacting steel plate, the current value is then decreased, and then the current value is increased again, and the main current is carried out at a constant current, or a pulse of the main current pass is performed. The suppression of the occurrence of spark in welding by chaPetition points 870190081229, of 8/21/2019, p. 7/47
    4/37 high strength pas is described there.
    [0011] JP-A No. 2006-181621 (sometimes referred to below as Document 4) describes a method for suppressing the occurrence of sparking in spot welding of high strength steel plates by spot welding as the value current is increased, while repeatedly increasing and decreasing the current, as illustrated in Fig. 6.
    [0012] An ISO 18278-2 resistance welding and weldability - Part 2 Alternative procedure for assessing steel plates for spot welding (sometimes referred to below as Document 5) describes a method of spot welding in which, as shown in Fig. 7, for steel plates 1.5 mm thick or more, six cycles (120 milliseconds) or more of current flow and two cycles (40 milliseconds) of rest are repeated three times or more .
    Summary of the invention
    Technical problem [0013] An objective of the present invention is to provide a resistance spot welding method for assembling sheets of superimposed steel material including a high strength steel sheet, the method allowing a wide adequate current range to be guaranteed , even when using a direct current inversion method.
    Solution to the problem [0014] As a specific example of such a method, the inventors investigated using a 1500 Mpa grade hot-stamped steel sheet with treated surface in various sheet assemblies. As a result, they found that stable spot welding, in which internal sparking and surface sparking are suppressed and having a suitable wide current range, can
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    5/37 be implemented by combining a process in which a pulsating current is passed for a short period of time (several repetitions of current flow and current flow stop) followed by a process of direct current flow.
    [0015] One aspect of the present invention provides a resistance spot welding method including: a pulsation process of securing a sheet assembly of two or more overlapping steel sheets including at least one high strength steel sheet using a pair welding electrodes that are connected to a spot welding power source using a direct current inversion method, and perform several repetitions of current flow and current flow interruptions, while pressing steel sheets with the electrode is welding; and a direct current passing process in which, after the pulsation process, the current is passed continuously for a longer period of time than the maximum current passing time of the pulsation process, while pressing the steel sheets with process electrodes.
    Advantageous effects of the invention [0016] The resistance spot welding method of the present invention allows a wide range of suitable current to be guaranteed, even in cases where the direct current inversion source is used to perform spot welding of the plate assembly of superimposed steel plates including a high-strength steel plate.
    Brief description of the drawings [0017] Fig. 1 is an explanatory diagram illustrating schematically the relationship between welding time and current in a single step current flow method in which the current flow is performed only once.
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    6/37 [0018] Fig. 2 is an explanatory diagram illustrating schematically the relationship between welding time and current in a current flow method in Document 1.
    [0019] Fig. 3 is an explanatory diagram illustrating schematically the relationship between time and welding current in a current flow method of Document 2.
    [0020] Fig. 4 is an explanatory diagram illustrating schematically the relationship between time and the welding current in a current flow method of Document 3.
    [0021] Fig. 5 is an explanatory diagram illustrating schematically the relationship between time and the welding current in a current flow method of Document 3.
    [0022] Fig. 6 is an explanatory diagram illustrating schematically the relationship between time and the welding current in a current flow method of Document 4.
    [0023] Fig. 7 is an explanatory diagram illustrating schematically the relationship between time and the welding current in a current flow method of Document 5.
    [0024] Fig. 8 is a schematic diagram illustrating the resistance spot welding equipment according to an example of configuration of the present invention.
    [0025] Fig. 9 is an explanatory diagram schematically illustrating the relationship between welding time and current in a current transfer method from a resistance spot welding method as an example of the present invention.
    [0026] Fig. 10A is an explanatory diagram illustrating schematically the relationship between welding time and current from a variation of pulsation processes of the current passing method in a resistance spot welding method for a
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    7/37 example of configuration of the present invention.
    [0027] Fig. 10B is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of pulsation processes of the through current method in a resistance spot welding method as a configuration example of the present invention.
    [0028] Fig. 10C is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of pulsation processes of the current passing method in a resistance spot welding method according to a configuration example of the present invention.
    [0029] Fig. 10D is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of pulsation processes of the current passing method in a resistance spot welding method according to a configuration example of the present invention.
    [0030] Fig. 10E is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of pulsation processes of the current passing method in a resistance spot welding method according to a configuration example of the present invention.
    [0031] Fig. 10F is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of pulsation processes of the current passing method in a resistance spot welding method according to a configuration example of the present invention.
    [0032] Fig. 10G is an explanatory diagram illustrating schematically the relationship between welding time and current from a variation of pulsation processes of the current passing method in a spot welding method to resistance 870190081229, of 21 / 08/2019, p. 11/47
    8/37 and an example configuration of the present invention.
    [0033] Fig. 10H is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of pulsation processes of the current passing method in a resistance spot welding method according to a configuration example of the present invention.
    [0034] Fig. 11A is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of the method of direct current passage in a resistance spot welding method according to a configuration example of the present invention. .
    [0035] Fig. 11B is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of the method of direct current passing in a resistance spot welding method according to a configuration example of the present invention .
    [0036] Fig. 11C is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of the method of direct current passage in a resistance spot welding method as an example of the present invention .
    [0037] Fig. 11D is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of the method of direct current passage in a resistance spot welding method according to a configuration example of the present invention. .
    [0038] Fig. 11E is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of the method of direct current passage in a resistance spot welding method according to a confiPetition example 870190081229, of 08/21/2019, p. 12/47
    9/37 of the present invention.
    [0039] Fig. 11F is an explanatory diagram schematically illustrating the relationship between welding time and current from a variation of the direct current method in a resistance spot welding method as an example of the present invention. .
    [0040] Fig. 11G is an explanatory diagram illustrating schematically the relationship between welding time and current of a variation of the method of direct current passage in a resistance spot welding method according to a configuration example of the present invention. .
    Description of configurations [0041] Below is an explanation regarding a resistance spot welding method according to an example configuration of the present invention. In Fig. 9, Fig. 10A to Fig. 10H, and Fig. 11A to Fig. 11G, I on the vertical axis indicates the welding current, and t on the horizontal axis indicates the time.
    [0042] Recently, the use of several high-strength steel plates as automotive materials is increasing, to achieve lighter vehicle chassis and improve crash safety. The application of hot stamping (a method in which, after heating the steel sheet to a hardening temperature and converting to austenite, the pressing is carried out in a mold at the same time as cooling and tempering) is becoming predominant, and pressed components of ultra high strength having a tensile strength of 1200 to 2000 MPa are produced by hot stamping.
    [0043] Sometimes the surface of the steel sheets used in hot stamping, instead of being uncoated, have the surface treated to prevent the iron scale from being generated when
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    10/37 of heated to a high temperature, such as by zinc-based coating, aluminum-based coating, etc. Hot stamped steel sheets are, in many cases, molded chassis that have been molded instead of flat sheets, and in the present invention, hot stamped steel sheets include molded chassis. In addition, in the following explanation, hot-stamped steel sheets obtained by hot stamping of zinc-coated steel sheets are sometimes referred to as hot-stamped steel sheets with a treated surface.
    [0044] When hot-stamped steel sheets are spot welded with a spot welding machine with a direct current inversion source, in contrast to mild steel sheets, sparking is generated at lower current values than when a single phase alternating current source is used, leading to the phenomenon of narrowing the range of suitable currents. This phenomenon that occurs, for example, in spot welding of hot-stamped steel sheets coated with aluminum, was reported in the document Schweissen Schneiden by LAURENZ et al., 64-10 (2012), 654-661 (sometimes referred to below as Document 6), however, there were no reports of its fundamental solutions.
    [0045] In particular, with hot-stamped steel sheets with treated surface, when spot welding is carried out with a spot welding machine with a direct current inversion source, internal sparking and surface sparking are liable occur, and the appropriate current range is significantly narrowed. The diameter of the nugget that can be obtained without generating sparks therefore becomes smaller.
    [0046] Although the causes of the above are not clear, it is thought that the occurrence of internal sparking is as follows.
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    With hot-stamped steel sheets with treated surface, due to a bonding reaction that occurs between the zinc-based coated film or the aluminum-based coated film, and the base steel sheet material, the solid compound solution intermetallic and the base iron is formed on its surface, and there is also an oxide film present on the outer surface that has a metal component derived from the coating (for example, zinc, in the case of zinc based coating). This, consequently, makes the resistance in the contact portions between the steel sheets higher in hot-stamped steel sheets with treated surface than in untreated steel sheets, leading to a large amount of heat generation.
    [0047] However, as the bonding of the coating and steel progresses during the hot stamping process, the melting point in the vicinity of the surface becomes a high value, close to that of the iron, and then the contact portions between the plates steel plates are less easily softened than steel plates before heating which have coating films present, preventing the current path from spreading. In particular, because the heat generation efficiency is higher in a direct current inversion method due to the current being continuously inserted than with a single phase alternating current, the formation of nuggets in the initial stage of a current passage is extremely fast. It is a hypothesis that, for this reason, the growth of the pressure welding portions on the periphery of the nuggets does not gain momentum, so that the molten metal can no longer be contained, leading to the generation of internal sparking.
    [0048] Regarding the causes of surface spark, imagine that they are similar to the causes of the occurrence of internal spark described above. In addition, in a method of inversion of
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    12/37 direct current, due to the current being inserted continuously, there is no current interruption time as in the case of single phase alternating current, and the cooling effect of the electrodes is difficult to obtain. It is, therefore, considered as a hypothesis that the nuggets grow immediately in the direction of the thickness of the plate, and the molten portion reaches the outer layer of the steel plate, leading to the occurrence of surface sparkling.
    [0049] With hot-stamped steel sheets with treated surface, internal sparking and surface sparking are thought to be promptly generated due to the state of the surface described above, and the appropriate current range is often less than 1 kA in cases where the applied pressure is low. However, in reality, hardly any research has been carried out on spot welding methods to the resistance of mounting plates that include a hot stamped steel plate with treated surface.
    [0050] When the methods in Documents 1 to 5 are applied to hot-stamped steel sheets with treated surface, the following deficiencies arise.
    [0051] In the method of Document 1, which is a resistance spot welding method for high strength steel plates, due to the value of the current that can be applied to hot stamped steel plates with treated surface without sparking in a preparatory current pass that is low, the current passage path spreads at the interface between the steel plates and the current density drops, so there is not enough generation of the spark suppression effect. Thus, cases of internal sparking and surface sparking have been discovered that occurred when the current value is increased for the main current pass, and it was difficult to guarantee a sufficient adequate current range.
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    13/37 [0052] In the methods of Documents 2 and 3, similarly to the method of Document 1, the value of the chain that can be applied to the hot-stamped steel sheets with treated surface without sparking in, a preparatory chain pass is low. The upper limit of the preparatory current pass value is greater than that of Document 1, however cases of internal sparking have been discovered when the current value is increased for the main current pass, and it was difficult to guarantee an adequate current range .
    [0053] In the method described in Document 4, there is an effect of expanding the current range suitable for a steel material up to the degree of tensile strength of 980 Mpa, however the internal spark and surface spark occur promptly when the current it is increased the second and third times for hot-stamped steel sheets with a treated surface that have greater strength, and this chain pass pattern is not suitable for welding hot-stamped steel sheets with a treated surface.
    [0054] In the current pass method described in Document 5, the current pass is 6 cycles (120 milliseconds) even in the shortest case. For hot-stamped steel sheets with treated surface, the upper current limit cannot be increased using this current-pass method since internal sparking is generated in a current pass shorter than six cycles. The upper limit of the current value is increased when the current passing time is made shorter on each pulse, however the lower limit of the current value is also increased due to the drop in heat generation efficiency and, as a result, the suitable current range cannot be extended. This method, therefore, is not suitable.
    [0055] However, in contrast to this, in the welding method
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    14/37 by points to the resistance of the present example configuration, a wide range of suitable currents is guaranteed for high strength steel sheets, including a hot-stamped steel sheet with treated surface, even when the direct current inversion source it is used.
    [0056] Initially follows the explanation about a welding machine used in spot welding to the resistance of the present configuration example.
    [0057] As illustrated in Figure 8, the welding machine 10 includes electrodes 16, 18 that press and pass a welding current through overlapping steel sheets 12, 14, a pressing mechanism 20 that applies a specific welding force to the electrodes 16, 18, a press controller 22 that controls the welding force of the pressing mechanism 20, a welding power source 24 that applies current to electrodes 16, 18, and a current controller 26 that controls the power source welding 24 and controls the current value applied to electrodes 16, 18.
    [0058] A plate assembly that is the objective of a resistance spot welding method of the present configuration example is two or more superimposed steel plates, including at least one 590 Mpa high strength steel plate or more. Fig. 8 illustrates an assembly of superimposed plates of two plates 12, 14, however three or more plates can be used. Commonly, in the assembly of automotive vehicle chassis, resistance spot welding is performed to assemble two or three superimposed plates.
    [0059] There is no particular limitation as to the type of high-strength steel sheet, and, for example, precipitation-hardened sheets, DP steels, transformation-induced plasticity steels (TRIP), hot-stamped steel sheets, etc. , which have a
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    15/37 tensile strength of 590 MPa or more, are applicable as high strength steel plate. The resistance spot welding method of the present configuration example is applicable to a plate assembly including a high strength steel sheet having a tensile strength of 980 MPa or more. In particular, the application is preferably made to a plate assembly including a high strength steel plate having a tensile strength of 1200 MPa or more, and the application is most preferably done to a steel plate assembly including a steel plate. steel that has a tensile strength of 1500 MPa or more.
    [0060] The steel sheets included in the sheet assembly can be cold rolled steel sheets, or they can be hot rolled steel sheets. The steel sheets can be untreated steel sheets or coated steel sheets, and there is no particular limitation on the type of coating. The resistance spot welding method of the present configuration example is applicable to several high strength steel sheets, however, it is particularly applicable to hot stamped steel sheets with treated surface.
    [0061] There are no particular limitations on the thickness of high-strength steel sheets. For example, the thickness of the steel plates used in automobile components or vehicle chassis is 0.6 to 3.2 mm, and the resistance spot welding method of the present configuration example is suitable for application across that range. .
    [0062] The welding machine 10 is a spot welding machine including the welding power source 24 using a direct current inversion method. In cases where welding is carried out on assemblies that include high-strength steel sheets such as hot-stamped steel sheets, internal sparking and surface sparking are more likely to be generated at
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    16/37 a lower current value at the welding power source 24 using a direct current inversion method than with a welding power source than using a single phase alternating current method. The resistance spot welding method of the present configuration example is applied to the welding machine 10 that uses the spot welding source that uses such a direct current inversion method.
    [0063] The pressing mechanism 20 for the electrodes 16, 18 of the welding machine 10 can be those that press using a servomotor, or they can be those that press using air. The shape of the welding gun used can also be of the static type, type C or type X. There are no particular limitations on the welding force applied during welding, however the welding force is preferably controlled by the pressing controller 22 for 200 to 600 kgf. During spot welding, a constant welding force can be applied, or the welding force can be changed for each of the processes described later.
    [0064] There are no particular limitations for electrodes 16, 18 and, for example, dome ray (DR) type electrodes with an external circumferential radius of 6 to 8 mm can be used. A more typical example is the DR type electrodes having an external circumferential radius of 6 mm, and a radius of curvature of 40 mm. The electrode substance can be chromium, copper or copper reinforced with alumina dispersion, and it is preferably copper reinforced with alumina dispersion from the perspective of preventing soldering of the object and surface sparking.
    [0065] Here is the explanation regarding the resistance spot welding method performed using machine 10.
    [0066] Under control by pressing controller 22, electrodes 16, 18 hold the set of overlapping steel sheets 12 and 14
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    17/37 with a specific welding force, and the welding current pass from the welding energy source 24 is passed through the steel plates 12, 14 through the electrodes 16, 18 using a controlled current passing method by the current controller 26.
    [0067] In the current pass method, as shown in Fig. 9, initially a pulse wave current pass of a current value I0 and a time pass t0 is performed three times (see pulses P1 to P3 in Fig. 9). When this is being performed, an interruption time t1 in which the current is not passed is constant between each pulse. After the passing of an interruption time t2, in which the current is not passed after the final pulse P3 in the pulsation process (sometimes referred to as the final interruption time), a direct current pass process is then performed, as described later.
    [0068] The pulsation process goes from the appearance of the first pulse P1 until the end of the final interruption time t2.
    [0069] Pulse in the present configuration example includes inclined pulses and sawtooth pulses illustrated in the examples of the variations described later (see Fig. 10D and Fig. 10E).
    [0070] When the final interruption time t2 has passed after the end of the current flow in the final pulse P3 of the pulsation process, a direct current is passed from the electrodes 16, 18 through the steel plates 12, 14 to a value of current I1 which is less than the current value I0 of pulses P1 to P3, and for a current passing time t3 longer than the (maximum) current passing time t0 of each of pulses P1 to P3, and a specific nugget 28 is formed at the interface between the steel sheets 12, 14.
    [0071] In the pulsation process of the present configuration example, the pulses P1 to P3 correspond to a current that passes in the pulsation process of the present invention. The range of
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    18/37 interruption t1 and the range of the final interruption time t2 in the pulsation process of the present configuration example each correspond to the interruption of current flow of the pulsation process of the present invention. In addition, the interruption time range t1 between pulse P1 and P2, and P2 and P3, in the present configuration example corresponds to the interruption of current stop between the adjacent current passes in the present invention, and the interval time final interruption t2 of the present configuration example corresponds to the final current passage interruption of the present invention.
    [0072] Furthermore, the direct current flow process is performed after the pulsation process of the present invention, as in the present configuration example, however the interruption of the final current flow of the pulsation process is always positioned before the direct current pass.
    [0073] Performing spot resistance welding with this method of current pass obtains the following beneficial effects.
    [0074] In the pulsation process, the current passing time, the interruption time, and the number of pulses are adjusted according to the type of material, plate thickness, and plate assembly. The resistance spot welding method of the present configuration example allows the conformity between the contact faces of the steel sheets to be lifted in a short period of time, initially providing the pulsation process.
    [0075] In particular, in cases where the hot-stamped steel sheets with treated surface covered with a film of high electrical resistance, such as zinc oxide, the high melting oxide layer can be effectively removed from the side of the weld portion due to being able to induce vibration on the contact faces by thermal expansion and contraction due to repetitions
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    19/37 of current passes and interruptions of current passes. In addition, a cooling effect of the electrode can be operated sufficiently due to repetitions of current pass interruptions and pulsating current pass interruptions, allowing a rapid increase in the nugget temperature 28 to be suppressed, and thus allowing the advantageous effect to increase the conformity between the contact faces of the steel sheets 12, 14 in a short period of time, while suppressing the generation of internal sparking and surface sparking.
    [0076] The time of passage of current t0 of each of the pulses P1 to P3 in the pulsation process is preferably 10 milliseconds to 60 milliseconds. When the current pass time t0 is less than 10 milli seconds, the heating time is short and there is insufficient heat generation in the contact faces of the steel sheets 12, 14. When the current pass time t0 exceeds 60 milliseconds, the heating time is very long, there is a concern to increase the probability of surface sparking and internal sparking being generated. The current pass time t0 is more preferably 15 milliseconds or more. The current pass time t0 is more preferably 45 milliseconds or less, with 25 milliseconds or less being even more preferable.
    [0077] The value of current I0 of the welding current in the pulsation process is preferably from 7.0 to 14.0 kA. Normally, when the current pass time is increased in the pulse, this results in the spark being generated at low current values, and then preferably the current value is adjusted appropriately in the pulse current pass in order to be in a range of 7.0 to 14.0 kA considering the balance with the current pass time.
    [0078] The interruption times t1 in the pulsation process, ex
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    20/37, including the final interruption time t2, are preferably 10 milliseconds to 60 milliseconds each time. When the interruption times t1 are less than 10 milli seconds, the interruptions are short, and the cooling of the steel sheets 12, 14 is insufficient, leading to a concern regarding the generation of internal sparking and surface sparking. However, when the interruption times t1 exceed 60 milli seconds, there is a very large cooling effect from the electrodes 16, 18, leading to a concern regarding the decrease in the amount of nugget formation 28 in the continuous current passing process. subsequent. Interruption times t1 are preferably 15 milliseconds or more. Interruption times t1 are more preferably 45 milliseconds or less, and are even more preferably 25 milliseconds or less.
    [0079] The final interruption time t2 in the pulsation process is preferably from 10 milliseconds to 120 milliseconds. When the final break time t2 is less than 10 milli seconds, there is insufficient cooling of nugget 28, so that the sparking is generated at a low current value during the continuous current passing process. However, when the final break time t2 exceeds 120 milli seconds, nugget 28 is cooled too much, increasing the current value in the direct current pass to obtain the standard nugget diameter giving a specific joint resistance, resulting in a band of adequate narrow current. The final dwell time t2 is more preferably 15 milliseconds or more. The final dwell time is more preferably 100 milliseconds or less, and is even more preferably 60 milliseconds or less.
    [0080] Providing the pulsation process as a preparatory current pass in this way, the current pass can be repeated, while the cooling effect of the electrodes is spread
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    21/37
    16, 18. Consequently, while the generation of spark is suppressed due to the rapid growth of nugget 28 on the contact faces of the steel sheets 12, 14, the conformity of the high-strength steel sheet with the other steel sheet can be promoted , allowing an increase in the current path at the interfaces between the steel sheets can be achieved.
    [0081] Thus, by inserting the continuous current passing process after the pulsation process, a drop in the current density due to the increase in the current path between the steel plates 12, 14 is suppressed, and the generation of sparking is suppressed by suppressing the increase in temperature in the contact portions between the steel plates, even in cases where the continuous current flow is for a period of time longer than the (maximum) current flow time t1 of the respective pulses P1 to P3 in the pulsation process. That is, the value of the current at which the spark is generated is increased.
    [0082] Furthermore, after the growth of nugget 28 has started in the pulsation process, the current is passed in the continuous current passing process to the current passing time t3 which is greater than the current passing time t1 of each pulse of the pulsation process, nugget 28 grows to the specific standard nugget diameter at a lower current value than when the single current pass is used (see Fig. 1).
    [0083] As a result, in the resistance spot welding method of the present configuration example, the appropriate current range is increased in the continuous current passing process.
    [0084] Here the reference to the appropriate current range indicates a range defined by a lower limit of a current value that produces a standard nugget diameter 4t 1/2 (where t is the plate thickness (mm), also referred to below as 4 ^ t) able to obtain a force
    Petition 870190081229, of 8/21/2019, p. 25/47
    22/37 of specific welding, and with an upper limit of the maximum current value at which sparking (expulsions) is not generated. Plate thickness t is the thickness (mm) of a steel plate between the two steel plates on which the nugget is formed. In cases where the thicknesses of the two steel sheets are different from each other, the thickness of the sheet t is that of the thinner steel sheet. In addition, in cases where there are three or more overlapping steel sheets, sheet thickness t is the thinnest of the steel sheets between the two steel sheets on which the nugget diameter is measured.
    [0085] Thus, using the resistance spot welding method according to the present configuration example, it allows a stable resistance spot welding to be performed, even for steel sheets including a hot-stamped steel sheet with surface treated that is liable to generate sparking.
    [0086] The resistance spot welding method according to the present configuration example allows the quality of the external appearance of a product to be increased by suppressing the generation of sparking. In addition, the operational availability of robots can be increased due to being able to prevent spark adherence to the moving parts of a welding robot. An improvement in productivity can also be achieved due to being able to omit the post-processing that accompanies sparking generation, such as burr removal.
    [0087] The number of pulses (current passes) in the pulsation process is at least two or more. This is because an advantageous sparking suppression effect cannot be achieved unless there are two or more pulses when using the hot stamped steel plate with treated surface. The number of pulses is more preferably three or more. Generally, the number of pulses
    Petition 870190081229, of 8/21/2019, p. 26/47
    23/37 must be increased as the thickness of the plate assembly increases. However, due to a tendency to saturation of the advantageous effect when there are more than nine pulses, the number of pulses is preferably nine times or less.
    [0088] In cases where the application is made on a hot-stamped steel plate with a treated surface that is liable to generate sparking, in the pulsation process, for example, preferably current passes from 7.5 kA to 12 kA for 16.6 milli seconds (one cycle at 60 Hz) at 20 milli seconds (one cycle at 50 Hz) and interruptions are performed repeatedly three to seven times.
    [0089] The resistance spot welding method of the present configuration example includes the continuous current passing process after the pulsation process. If only the pulsation process is employed, even if the current path can be increased, there is only a small effect in increasing the nugget's diameter; however, by providing the continuous current flow process after the pulsation process, heat generation is promoted at the interface between the steel plates 12, 14, allowing the nugget 28 to be formed to a sufficient size without causing internal sparking and surface sparking are generated.
    [0090] In the continuous current pass process, the current pass time t3 is preferably a continuous current pass performed from 100 milliseconds to 500 milliseconds. When the current pass time t3 in the continuous current pass process is less than 100 milliseconds, the time is insufficient to increase the nugget 28 and the effect is not obtained. When the current pass time t3 exceeds 500 milli seconds, there is saturation in the effect to increase nugget 28, leading to an increase in takt time. The current pass time t3 in the continuous current pass process is more preferably 120 milliseconds or more, and is more preferable Petition 870190081229, of 21/08/2019, pg. 27/47
    24/37 400 milliseconds or less.
    [0091] The current value I1 in the continuous current passing process is preferably from 5.0 kA to 12.0 kA. The current value I1 in the continuous current passing process is preferably the maximum current value I0 in the pulsation process or less. Making the current value I1 in the continuous current passing process less than the maximum current value I0 in the pulsation process is done to suppress the generation of sparking. In a continuous current pass process, the current value does not necessarily have to be constant, and a change can be made to the current value during the continuous current pass process, and an upward or downward slope of 16 milliseconds to 60 milliseconds can be included.
    [0092] When using a high-strength steel plate, such as a hot-stamped steel plate, another single chain pass or pulsing current pass can be performed after the continuous current pass process, to control the cooling process and increase the toughness of nugget 28 (see Fig. 11F, Fig. 11G). Performing another chain pass after the continuous chain passing process has the advantages of increasing the toughness of nugget 28 by smoothing the segregation in the solidification of phosphorus in nugget 28 and by transforming nugget 28 into a tempered martensite structure, allowing resistance to of the spot welded joint is increased.
    [0093] In the resistance spot welding method according to the present configuration example, another pressing retention process by electrodes 16, 18 without current flow can be provided after the pulsation process and the continuous current pass process described above have ended. The provision of the retention process allows the solidification fracture within the nugget 28
    Petition 870190081229, of 8/21/2019, p. 28/47
    25/37 is deleted. There are no particular limitations on the retention time when the retention process is provided; however, since the takt time increases when the retention time is too long, the retention time is preferably 300 milliseconds or less.
    [0094] The current value I0, the current pass time t0, and the interruption time t1 for each of the pulses P1 to P3 in the pulsation process can be constant, or they can vary for each pulse.
    [0095] That is, when resistance spot welding is performed on steel plates in a two-plate assembly, there is no limitation for a configuration in which, as in the present configuration example, the current pass time for each one of the pulses in the pulsation process and the interruption time of the current pass between each of the pulses is constant, and the current value of each pulse is constant.
    [0096] For example, as shown in Fig. 10A, control can be performed so that the current value increases after the first pulse P1 in the progression through pulses P2, P3. In addition, as shown in Fig. 10D, the increasing portion of the first pulse P1 can be tilted. In addition, as illustrated in Fig. 10E, the rising sides of each of the pulses P1 to P3 can be angled to give a sawtooth shape. In addition, as illustrated in Fig. 10G, a first interruption time t1 between the first pulse P1 and the second pulse P2 can be configured alone so that it is longer than another interruption time t12, increasing the cooling effect of the electrode of the first pulse P1 compared to another pulse P2.
    [0097] Using this method of current passing in the pulsation process suppresses the rapid growth of nugget 28 in the pulsation process (suppresses the rapid increase in temperature in that portion),
    Petition 870190081229, of 8/21/2019, p. 29/47
    26/37 allowing the generation of internal sparking and surface sparking to be suppressed.
    [0098] Furthermore, for example, as shown in Fig. 10H, a configuration in which the final interruption time t2 (the interruption time of the current pass between the final pulse P3 and the continuous process of current) is shorter than the other examples (see Fig. 10 to Fig. 10G). By making the final break time t2 shorter in this way, excessive cooling of the steel sheets 12, 14 by the electrodes 16, 18 is suppressed, allowing the electrical energy transmitted to the steel sheets (for example, the pass time current value) during the continuous current pass is suppressed.
    [0099] In addition, in cases where resistance spot welding is performed for an assembly of three steel plates in which a thin plate is superimposed on the outside of two thick plates, the following variation of the pass method of current can be considered in the pulsation process.
    [00100] For example, as illustrated in Fig. 10B, control can be performed in order to decrease the current value from the first pulse P1 in the progression towards the final pulse P3. In addition, as illustrated in Fig. 10C, the first pulse P1 alone can have a current pass with a higher current value than that of the other pulses P2. P3. In addition, as illustrated in Fig. 10F, the first pulse P1 alone can have a longer current pass time than the current pass time of the other pulses P2, P3.
    [00101] In this way, the electrical energy transmitted by the first pulse P1 to the assembly of three steel sheets is a higher electrical energy than that transmitted in the other pulses P2, P3. Due to the transmission of high electrical energy at the point of time when there is a high contact resistance between the thin plate and the thick plate,
    Petition 870190081229, of 8/21/2019, p. 30/47
    27/37 this also allows a high temperature to be achieved in the thin plate and the thick plate, and a nugget to be developed between them. [00102] Similarly, an explanation follows of the variations in the current pass method of the continuous current pass method of the spot welding method to the resistance of the present configuration example, in relation to Figs 11A to Fig. 11G.
    [00103] For example, as shown in Fig. 11A, by tilting the increase in the current waveform in the continuous current passing process, or, as shown in Fig. 11E, by adjusting the current value for the first half of the continuous current pass process less than the current value of the final half, a rapid increase in nugget temperature 28 can be suppressed the moment the continuous current pass is initiated, allowing the generation of internal sparking and of surface sparking is suppressed. [00104] Furthermore, there are no configurations in which, as illustrated in Fig. 11B, the current waveform drop of the continuous current passing process is inclined, or in which, as shown in Fig. 11C, the value current of the last half of the continuous current passing process is set less than the current value of the first half. Adopting such an approach allows the resistance of the welded joint to be increased, cooling gradually after welding in order to change the characteristics of the metal structure of the weld portion.
    [00105] In addition, for example, as illustrated in Figure 11F and Fig. 11G, there are also configurations in which, after the continuous current pass process, a single current pass is performed, or the pulsating current pass is performed executed. This improves the metal structure of the weld portion, and increases the strength of the weld joint.
    [00106] Furthermore, as illustrated in Fig. 11D, the growth of
    Petition 870190081229, of 8/21/2019, p. 31/47
    28/37 nugget is promoted between a thin plate and a thick plate by passing the chain through an assembly of plates of three superimposed plates, these being a thin plate, a thick plate, and a thin plate, with a high value of current initially in the continuous current passing process.
    Examples [00107] The explanation in relation to the examples follows; however, the present invention is not limited to these examples.
    Example 1 [00108] The welding machine used in the present examples is a spot welding machine with direct current inversion that uses a servo pressing method, and includes DR type electrodes (copper reinforced with alumina dispersion) having a radius external circumferential curvature of 6 mm, and a radius of curvature of 40 mm. The material to be welded are two overlapping sheets of hot-stamped steel sheets coated with aluminum of the 1500 Mpa class (the amount of cooling before hot stamping was 40 g / m 2 per side, and the heating conditions are heating in a gas oven at 900 ° C for 4 minutes) with a plate thickness of 1.2 mm and a dimension of 30 mm x 100 mm.
    [00109] The welding methods are listed in Table 1. Although the test points 6, 7 including a current pass before the continuous preparation process stream pass, they are tests in which a two - stage cross current runs without an interruption time between the preparatory chain pass and the continuous chain pass process. Test No. 8 is configured with a current pass interruption time (34 milli seconds) between the preparatory current pass and the continuous current pass process. In both examples of the present invention and examples
    Petition 870190081229, of 8/21/2019, p. 32/47
    29/37 comparative, the welding force was a constant value (300 kgf) in the pulsation process or in the preparatory current pass, and in the continuous current pass process.
    [00110] In each of the tests, spot welding was performed by varying the current value of the continuous current pass process while maintaining the conditions of the pulsation process or the constant preparatory current pass, the value is discovered minimum current (current 4 ^ t) in which the nugget diameter, this being the determinant of the resistance of the welding joint, reaches 4 t (where t is the plate thickness in mm) = 4.3 mm or more, and the maximum current value (maximum value without sparking) at which the sparking (internal sparking and surface sparking) is not generated is discovered. The range from current value 4 t to the maximum current value without sparking, that is, the range of current values for the continuous current passing process so that sparking is not generated, while still forming a nugget. which transmits a specific resistance to the weld joint, is the appropriate current range. The test results are shown in Table 1.
    [00111] Regarding the nugget diameter, after spot welding, a destructive test was performed using a chisel, and the fracture was measured using a Vernier calibrator. The presence or absence of sparking was confirmed by eye during spot welding.
    Petition 870190081229, of 8/21/2019, p. 33/47
    Table 1
    Test No. Pulsation process Continuous current passing process Test results (current values of the continuous current passing process)Welding current Current pass time Current interruption time other than end Final current interruption time Number of pulses Current pass time Chain4 <t Maximum non-sparking current value Suitable current range Comment (kA) (ms) (ms) (ms) (times) (ms) (kA) (kA) (kA) - 1 8.5 17 17 17 3 133 5.5 8 2.5 Examples of the present invention 2 8.5 17 17 60 3 133 5.5 8.2 2.7 3 7.5 34 34 34 3 133 5.8 8.5 2.7 4 7.5 17 17 51 9 133 4.6 7.8 3.2 5 - - - - - 250 5 5.5 0.5 Purchasing Examples 6 Preliminary current of 5.0 kA for 83 ms 133 5.8 6.2 0.4 7 Preliminary current of 5.0 kA for 83 ms 250 5.2 6 0.8 8 Preliminary current of 5.0 kA for 83 ms + 34 ms interruption 250 5.5 6.5 1
    30/37
    Petition 870190081229, of 8/21/2019, p. 34/47
    31/37 [00112] As shown in Table 1, the appropriate test current ranges of paragraphs 1 to 4 of the examples of the present invention include heartbeat process is three or more times larger than those of Tests Nos 5 to 7 of the comparative examples, which either do not have a preparatory current pass, or have a preparatory current pass but do not have an interruption time provided between the preparatory current pass and the continuous current pass. Furthermore, it was confirmed that the appropriate current ranges of tests Nos 1 to 4 of the examples of the present invention include heartbeat process (several repetitions of current passes and interrupts) are two or more times larger than those of the test from comparative example n ° 8 which has an interruption time provided between the preparatory current pass and the continuous current pass.
    Example 2 [00113] The welding machine used in the present examples is the same as in Example 1. The material to be welded were three overlapping sheets, these being a 270 MPa grade GA coated steel sheet with a sheet thickness of 0.7 mm and a dimension of 30 mm x 100 mm, a 1500 MPa grade GA coated hot stamped steel sheet with a sheet thickness of 1.2 mm (the amount of coating before hot stamping was 55 g / m 2 per side, and the heating conditions were the same as those of Example 1), and a 440 MPa grade uncoated steel sheet with a sheet thickness of 1.4 mm. The welding methods are listed in Table 2. The current pass methods of the comparative examples are similar to those of Example 1. In both examples of the present invention and the comparative examples, the welding force was a constant value (300 kgf) in the pulsation process or in the preparatory current pass, and in the continuous current pass process.
    Petition 870190081229, of 8/21/2019, p. 35/47
    32/37 [00114] Tests and test evaluation results were performed similarly to Example 1.
    [00115] The current value 4 t was determined as follows, due to the thickness being different in the three plates. Namely, the minimum current value at which the nugget diameters at the respective interfaces between the steel sheets respectively satisfied 4 t (where t is the thickness of the sheet in mm on the side of the thin sheet on an overlapping face) is the value of current 4 ^ t. Specifically, for the nugget at the interface between the 0.7 mm thick steel plate and the 1.2 mm thick steel plate and the 1.4 mm thick steel plate, the nugget diameter is 4 t when is 4 χ (0.7) 1/2 = 3.4 mm. For the nugget at the interface between the 1.2 mm thick steel plate and the 1.4 mm thick steel plate, the nugget diameter is 4 t when it is 4 χ (0.7) 1/2 (= 4.4 mm) or greater. Thus, the current value 4 t is the minimum current value in which the nugget diameters at both interfaces are respectively 4 t or greater.
    [00116] The test results are shown in Table 2.
    Petition 870190081229, of 8/21/2019, p. 36/47
    Table 2
    Test No. Pulsation process Continuous current passing process Test results (current values of the continuous current passing process)Welding current Current pass time Current interruption time other than end Final current interruption time Number of pulses Current pass time Chain4 <t Maximum non-sparking current value Suitable current range Comment(kA) (ms) (ms) (ms) (times) (ms) (kA) (kA) (kA) - 1 12 17 17 17 3 282 5.8 8.6 2.8 Examples of the present invention 2 12 17 17 34 3 282 6 8.8 2.8 3 12 17 17 17 3 500 5.6 8.8 3.2 4 - - - - - 282 5.8 6.6 0.8 Purchasing Examples 5 Preliminary current of 5.0 kA for 83 ms 282 5.8 6.6 0.8 6 Preliminary current of 5.0 kA for 83 ms + 34 ms interruption 282 6 7 1
    33/37
    Petition 870190081229, of 8/21/2019, p. 37/47
    34/37 [00117] As shown in Table 2 with the material to be welded of three superposed plates also including hot stamped material, it was confirmed that similarly to Example 1, the appropriate test current ranges of paragraphs 1 to 3 the present invention includes the heartbeat process is almost three times larger (2.0 kA or more) than those of tests Nos a6 4 of the comparative examples do not have a pass or preparatory chain, or have a pass preparatory current but do not have an interruption time provided between the preparatory current pass and the continuous current pass, or have an interruption time provided between the preparatory current pass and the continuous current pass.
    Example 3 [00118] The welding machine used in the present examples is a spot welding machine with direct current inversion that uses an air pressing method, and includes electrodes of the type DR (copper reinforced with alumina dispersion) having a external circumferential radius of curvature of 6 mm, and a radius of curvature of the tip of 40 mm. The material to be welded were two hot-stamped steel sheets of 1500 MPa grade coated with Al treated surface heated in an overlapping ZnO oven having a thickness of 1.6 mm and a dimension of 30 mm x 100 mm. The welding methods are listed in Table 3. The current passing methods in the comparative examples of the present invention are similar to those in example 1. The welding force in the examples was a constant value (350 kgf) in the pulsation process or in the pass preparatory current flow, and in the continuous current passing process.
    [00119] The tests and the evaluation of the test results were performed similarly to Example 1.
    [00120] The test results are shown in Table 3.
    Petition 870190081229, of 8/21/2019, p. 38/47
    Table 3
    Test No. Pulsation process Continuous current passing process Test results (current values of the continuous current passing process)Welding current Current pass time Current interruption time other than end Final current interruption time Number of pulses Current pass time Chain4 <t Maximum non-sparking current value Suitable current range Comment (kA) (ms) (ms) (ms) (times) (ms) (kA) (kA) (kA) - 1 7.5 17 17 50 7 333 5.7 7.3 1.6 Examples of the present invention 2 8.5 17 17 50 7 333 5.5 7.6 2.1 3 9.5 17 17 50 7 333 5.5 7.2 1.7 4 8.5 17 17 50 9 250 5.5 7.5 2 5 - - - - - 333 5.7 6.4 0.7 Purchasing Examples 6 - - - - - 600 5.5 6.5 1 7 Preliminary current of 5.0 kA for 83 ms 333 5.7 6.5 0.88 Preliminary current of 5.0 kA for 83 ms + 34 ms interruption 333 6.0 7.0 1
    35/37
    Petition 870190081229, of 8/21/2019, p. 39/47
    36/37 [00121] The hot-stamped steel sheet treated with ZnO film used in the present examples was produced by the following method.
    [00122] The cold-rolled steel sheet with a thickness of 1.6 mm was coated with Al using a Sendzimir process. The annealing temperature when this was done was about 800 ° C, and the Al coating bath contained 9% Si, and also contained Fe eluted from a steel strip. The amount of coating was then adjusted to 4 g / m 2 per side using a gas drying method. Water was sprayed in a spray during cooling after coating to adjust the surface roughness of the Al coating layer. After cooling the Al coated steel plate, a process liquid was coated onto the plate using a coating, and then burnt at about 80 ° C. The process liquid had a base of a ZnO paste from a NANOTEK (trademark) paste produced by CI Kasei Co. Ltd., to which water-soluble urethane resin was added as a binder at a maximum solid content of 30%, and carbon black for coloring to a maximum solid content of 10%. The amount adhered to was measured by the Zn content, and was adjusted to 0.8 g / m 2 . After the steel sheets produced in this way were heated in an oven at 900 ° C for 5 minutes in an air atmosphere, they were quickly cooled in a water-cooled mold to produce the test material.
    [00123] As shown in Table 3, with the material to be welded from the two hot-stamped steel sheets coated with Al treated with a ZnO film also, similarly to Examples 1, the upper current limit value in the continuous pass process current (the maximum current value without sparking) must be increased in tests Nos 1 to 4 of the present invention having a pulse process, compared with those of tests Nos 5 to 8 of the examples compa
    Petition 870190081229, of 8/21/2019, p. 40/47
    37/37 ratives that either do not have a preparatory chain pass, have a preparatory chain pass but do not have an interruption time provided between the preparatory chain pass and the continuous chain pass, or have an interruption time between the pass preparatory current and continuous current pass, and an extension of the appropriate current range (up to 1.5 kA or more) has been confirmed.
    [00124] The entire content of the Japanese Patent Application No. 2013-145380 description registered on July 11, 2013 is incorporated for reference in this specification.
    [00125] All publications, patent applications and technical standards mentioned in this specification are incorporated for reference in this specification to the same extent as if the individual publication, patent application, or technical standard was specifically or individually indicated to be incorporated for reference. .
    权利要求:
    Claims (10)
    [1]
    1. Resistance spot welding method, characterized by the fact that it consists of:
    a pulsation process of holding the assembly of sheets of two or more overlapping steel sheets (12, 14) including at least one high strength sheet using a pair of welding electrodes (16, 18) that are connected to a source of spot welding energy (24) using a direct current inversion method, and performing a plurality of repetitions of current passes and interruptions of current passes, while pressing the steel plates (12, 14) with the electrodes of welding (16, 18), and a continuous current pass process in which, after the pulsation process, the current is passed continuously for a period of time longer than the maximum current pass time of the pulsation process, while press the steel sheets (12, 14) with the welding electrodes (16,18).
    [2]
    2. Method, according to claim 1, characterized by the fact that in the pulsation process, the current passing times in the current passes are, each, from 10 milliseconds to 60 milliseconds.
    [3]
    3. Method, according to claim 1 or 2, characterized by the fact that in the pulsation process, the interruption times of the current passes between adjacent current passes are, each, from 10 milliseconds to 60 milliseconds.
    [4]
    Method according to any one of claims 1 to 3, characterized in that in the pulsation process, an interruption time of the final current pass between a final current pass and the continuous current pass process is 10 milliseconds to 120 milliseconds.
    [5]
    5. Method according to any of the claims
    Petition 870190081229, of 8/21/2019, p. 42/47
    2/2
    2 to 4, characterized by the fact that a current value of the current passes in the pulsation process is 7.0 kA to 14.0 kA.
    [6]
    Method according to any one of claims 2 to 5, characterized in that a current passing time in the continuous current passing process is from 100 milliseconds to 500 milliseconds.
    [7]
    7. Method, according to claim 6, characterized by the fact that the current value of a current pass in the continuous current passing process is from 5.0 kA to 12.0 kA.
    [8]
    8. Method according to claim 7, characterized by the fact that a maximum current value in the continuous current flow process is a maximum current value in the pulsation process or less.
    [9]
    Method according to any one of claims 1 to 8, characterized in that the high-strength steel sheet is a hot-stamped steel sheet having a surface covered with a zinc-based film or a foil with aluminum base.
    [10]
    Method according to any one of claims 1 to 9, characterized in that it executes another chain pass after the continuous chain pass process.
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US5483035A|1993-09-21|1996-01-09|Nadex Co., Ltd.|System for and method of controlling resistance welder|
    JP3291110B2|1994-02-24|2002-06-10|株式会社ナ・デックス|Control device and control method for resistance welding machine|
    JP3350216B2|1994-05-11|2002-11-25|株式会社ナ・デックス|Control device and control method for resistance welding machine|
    JP2003236674A|2002-02-15|2003-08-26|Mazda Motor Corp|Method and equipment of spot welding of high tensile steel|
    RU2243071C2|2002-07-01|2004-12-27|Открытое акционерное общество "АВТОВАЗ"|Method for contact spot welding of zinc-plated steel sheets|
    JP4753411B2|2004-12-28|2011-08-24|ダイハツ工業株式会社|Energization control method for spot resistance welding|
    JP4728926B2|2006-10-16|2011-07-20|新日本製鐵株式会社|Lap resistance spot welding method|
    US20090165455A1|2007-12-31|2009-07-02|Shlomo Gilboa|Methods and apparatus for energy production|
    KR100933846B1|2008-05-30|2009-12-24|주식회사 하이닉스반도체|Voltage generator and nonvolatile memory device having same|
    US9079266B2|2008-09-30|2015-07-14|Neturen Co., Ltd.|Welding equipment for metallic materials and method for welding metallic materials|
    JP5293227B2|2009-01-30|2013-09-18|Ｊｆｅスチール株式会社|Resistance spot welding method for high strength thin steel sheet|
    JP5359571B2|2009-02-12|2013-12-04|新日鐵住金株式会社|Resistance welding method for high strength steel sheet and manufacturing method for resistance welding joint|
    JP2010188408A|2009-02-20|2010-09-02|Honda Motor Co Ltd|Energization method for resistance welding|
    JP5332857B2|2009-04-20|2013-11-06|新日鐵住金株式会社|Resistance welding method for high strength steel sheet|
    JP5043236B2|2009-08-31|2012-10-10|新日本製鐵株式会社|Spot welding joint and spot welding method|
    KR101593642B1|2010-06-29|2016-02-16|한양대학교 산학협력단|Inverter dc resistance spot welding system, control method for welding process thereof and design method for fuzzy controller thereof|
    JP5653116B2|2010-08-03|2015-01-14|株式会社ダイヘン|Resistance welding control method for plated steel sheet|
    JP5333560B2|2011-10-18|2013-11-06|Ｊｆｅスチール株式会社|Resistance spot welding method and resistance spot welding joint of high strength steel plate|
    JP5923273B2|2011-10-21|2016-05-24|中央精機株式会社|Wheel rim upset welding method|EP3053693B1|2013-10-04|2018-02-21|JFE Steel Corporation|Resistance spot welding method|
    CN107427953B|2015-03-05|2019-10-08|杰富意钢铁株式会社|Resistance spot welding method and welding point|
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    法律状态:
    2019-06-11| B06A| Patent application procedure suspended [chapter 6.1 patent gazette]|
    2019-09-10| B25D| Requested change of name of applicant approved|Owner name: NIPPON STEEL CORPORATION (JP) |
    2019-11-12| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 26/06/2014, OBSERVADAS AS CONDICOES LEGAIS. (CO) 20 (VINTE) ANOS CONTADOS A PARTIR DE 26/06/2014, OBSERVADAS AS CONDICOES LEGAIS |
    2021-05-04| B21F| Lapse acc. art. 78, item iv - on non-payment of the annual fees in time|Free format text: REFERENTE A 7A ANUIDADE. |
    2021-08-24| B24J| Lapse because of non-payment of annual fees (definitively: art 78 iv lpi, resolution 113/2013 art. 12)|Free format text: EM VIRTUDE DA EXTINCAO PUBLICADA NA RPI 2626 DE 04-05-2021 E CONSIDERANDO AUSENCIA DE MANIFESTACAO DENTRO DOS PRAZOS LEGAIS, INFORMO QUE CABE SER MANTIDA A EXTINCAO DA PATENTE E SEUS CERTIFICADOS, CONFORME O DISPOSTO NO ARTIGO 12, DA RESOLUCAO 113/2013. |
    优先权:
    申请号 | 申请日 | 专利标题
    JP2013145380|2013-07-11|
    PCT/JP2014/067083|WO2015005134A1|2013-07-11|2014-06-26|Resistive spot welding method|
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