WO2014045431A1 - 継手強度に優れた高強度鋼板のスポット溶接方法 - Google Patents
継手強度に優れた高強度鋼板のスポット溶接方法 Download PDFInfo
- Publication number
- WO2014045431A1 WO2014045431A1 PCT/JP2012/074355 JP2012074355W WO2014045431A1 WO 2014045431 A1 WO2014045431 A1 WO 2014045431A1 JP 2012074355 W JP2012074355 W JP 2012074355W WO 2014045431 A1 WO2014045431 A1 WO 2014045431A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- energization
- steel plates
- strength
- spot welding
- thickness
- Prior art date
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K11/00—Resistance welding; Severing by resistance heating
- B23K11/16—Resistance welding; Severing by resistance heating taking account of the properties of the material to be welded
- B23K11/163—Welding of coated materials
- B23K11/166—Welding of coated materials of galvanized or tinned materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K11/00—Resistance welding; Severing by resistance heating
- B23K11/10—Spot welding; Stitch welding
- B23K11/11—Spot welding
- B23K11/115—Spot welding by means of two electrodes placed opposite one another on both sides of the welded parts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K11/00—Resistance welding; Severing by resistance heating
- B23K11/16—Resistance welding; Severing by resistance heating taking account of the properties of the material to be welded
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K11/00—Resistance welding; Severing by resistance heating
- B23K11/24—Electric supply or control circuits therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K11/00—Resistance welding; Severing by resistance heating
- B23K11/24—Electric supply or control circuits therefor
- B23K11/241—Electric supplies
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2101/00—Articles made by soldering, welding or cutting
- B23K2101/04—Tubular or hollow articles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/02—Iron or ferrous alloys
- B23K2103/04—Steel or steel alloys
Definitions
- the present invention relates to a spot welding method for a high strength steel plate having excellent joint strength, in which a welded portion is formed by spot welding in a process such as manufacture of automobile parts or assembly of a vehicle body.
- spot-welded joints The important characteristics of spot-welded joints (hereinafter referred to as spot-welded joints) include tensile strength and fatigue strength, but the most important is tensile strength.
- the tensile strength of spot welded joints includes tensile shear strength (TSS) measured by applying a tensile load in the shear direction and cross tensile strength (CTS) measured by applying a tensile load in the peeling direction. .
- the tensile strength of a spot welded joint is sufficiently high when there are no defects or cracks in the weld metal (nugget) and the weld metal has good properties, with a good fracture form and little variation in strength. TSS and CTS are obtained. Moreover, the tensile strength of a spot welded joint can also improve CTS by ensuring the nugget diameter (joining area) etc. sufficiently.
- two-stage energization is performed under certain conditions during welding energization, two-stage energization with cooling interposed, and three-stage energization. A spot welding method has been proposed (see, for example, Patent Document 1).
- the welded portion is cooled by holding the steel plate with the electrode held between the first step of forming the nugget by the main energization and the end of the first step.
- a method has been proposed that includes a second step and a third step of energizing a welding current higher than the main energization within a very short time after the end of the second step (for example, a patent). (Ref. 4).
- resistance spot welding is a welding consisting of three stages of a first stage, a second stage, and a third stage.
- a method is proposed in which high pressure, low current or the same current, long energization time or the same energization time is used, and the third stage repeats energization at a higher current than the second stage (for example, (See Patent Document 5).
- resistance spot welding is a welding consisting of three stages of a first stage, a second stage, and a third stage.
- a method has been proposed in which high pressure, low current or the same current, long energization time or the same energization time is used, and the third stage repeats high current energization at a higher pressure than the second stage. (For example, see Patent Document 6).
- the contact pressure (area) between the electrodes and the steel plates is increased by setting the pressure applied by the electrodes high, and the appropriate current range is prevented by preventing the occurrence of scattering.
- a method of ensuring a stable bonding area by enlarging is employed.
- the welding current is applied to the first step, the second step of applying 20% to 90% of the welding current of the first step, and the first step.
- a method that employs a welding energization pattern including a third step of energizing a larger welding current see, for example, Patent Document 7).
- the welding current is applied to the first step and 20% to 90% of the welding current of the first step, and the electrode pressing force is applied from the first step.
- a method has been proposed that employs a welding energization pattern that includes a second step that is set larger than the first step and a third step that increases the welding current and the applied pressure of the electrode as compared to the first step (for example, Patent Literature 1). 8).
- the present invention has been made in view of the above problems, and in particular, when spot-welding a high-strength steel sheet having a high tensile strength, the nugget diameter is ensured while suppressing the occurrence of indentation, and the occurrence of scattering. It is an object of the present invention to provide a spot welding method for a high strength steel sheet having excellent joint strength.
- a high strength steel sheet having a tensile strength of 780 MPa or more and 1850 MPa or less (hereinafter referred to as 780 to 1850 MPa) is welded by a resistance spot welding method.
- the electrode pressing force is set to an appropriate range according to the plate thickness of the steel plate, and further, the energization pattern is set to an appropriate range, thereby ensuring the nugget diameter while suppressing the occurrence of indentation and scattering. It has been found that it is possible to prevent the occurrence of.
- the gist of the present invention is as follows.
- Sheet thickness ratio ⁇ total thickness of steel plates ⁇ / ⁇ thickness of the steel plate on the thin side (plate thickness per sheet in the case of the same thickness) ⁇ is in the range of 3 or more and 6 or less
- the range is expressed by the following formula (1), 0.5 ⁇ P ⁇ 3.0t (1/3) (1)
- the welding current I1 is in a range of 30% or more and 90% or less of the welding current I2,
- Sheet thickness ratio ⁇ total thickness of steel plates ⁇ / ⁇ thickness of the steel plate on the thin side (plate thickness per sheet in the case of the same thickness) ⁇ is in the range of 3 or more and 6 or less
- the spot welding is a first energization step that is a pre-energization of a welding pressure P1 (k
- the applied pressures P1 and P2 are within the ranges represented by the following formulas (2) and (3), 0.5 ⁇ P2 ⁇ 3.0t (1/3) (2) 1.0 ⁇ P2 ⁇ P1 ⁇ 2.0 ⁇ P2 (3)
- the welding current I1 is in a range of 30% or more and 90% or less of the welding current I2, A spot welding method for a high strength steel sheet having excellent joint strength, wherein the second energization process is started within 0.1 (s) after the first energization process is completed.
- the gaps before spot welding of the stacked steel sheets are both less than 0.5 (mm). To do.
- the spot welding method of the high strength steel plate having excellent joint strength according to [2] at least one of the gaps before spot welding of the superposed steel plates is 0.5 (mm) or more. It is characterized by.
- the electrode pressing force is set to an appropriate range according to the plate thickness of the steel sheet, and an energization pattern consisting of pre-energization and main energization is optimized
- an energization pattern consisting of pre-energization and main energization is optimized
- FIG. 1 shows a state in which a weld metal part is formed by a resistance spot welding method, and is a cross-sectional view when two high-strength steel plates are stacked.
- FIG. 2 is a cross-sectional view showing a state in which a weld metal portion is formed by a resistance spot welding method, in which three steel plates including high-strength steel plates are stacked.
- FIG. 3 is a graph showing an example of the applied pressure and the energization pattern when forming the weld metal part by the resistance spot welding method in the first embodiment.
- FIG. 4 is a graph showing an example of a pressing force and an energization pattern when forming a weld metal part by a resistance spot welding method in the second embodiment.
- FIG. 1 shows a state in which a weld metal part is formed by a resistance spot welding method, and is a cross-sectional view when two high-strength steel plates are stacked.
- FIG. 2 is a cross
- FIG. 5 is a graph showing an example of a pressing force and an energization pattern when forming a weld metal part by a resistance spot welding method in the third embodiment.
- FIG. 6A is a schematic diagram showing a method for measuring the cross tensile strength.
- FIG. 6B is a schematic diagram showing a method for measuring the cross tensile strength.
- FIG. 3 is a diagram showing a list of production conditions and test results for each test piece in Example 1. It is a figure which shows the production conditions of each test piece in Example 2, and a list of test results. It is a figure which shows the production conditions of each test piece in Example 3, and the list of test results. It is a figure which shows the production conditions of each test piece in Example 4, and the list of test results.
- FIG. 1 is a schematic diagram showing a method for measuring the cross tensile strength.
- FIG. 3 is a diagram showing a list of production conditions and test results for each test piece in Example 1. It is a figure which shows the production conditions
- FIG. 11A is a schematic view showing a state in which a spacer steel plate is used in the method of measuring the cross tensile strength.
- FIG. 11B is a schematic view showing a state in which a spacer steel plate is used in the method of measuring the cross tensile strength.
- a high-strength steel plate is one having a tensile strength of 780 to 1850 MPa.
- Resistance spot welding method 1 and 2 are schematic views for explaining a resistance spot welding method used for welding the steel plate 1.
- two steel plates 1A and 1B which are materials to be welded, are overlapped.
- the two steel plates 1A and 1B are both high strength steel plates.
- the electrodes 2A and 2B made of copper alloy so as to be sandwiched from both sides with respect to the overlapping portion of the steel plates 1A and 1B, that is, as shown in FIG.
- a molten metal part is formed between the steel plates 1A and 1B.
- the molten metal portion is rapidly cooled and solidified by heat removal by the water-cooled electrodes 2A and 2B and heat conduction to the steel plates 1A and 1B, and then between the two steel plates 1A and 1B. Then, a nugget (welded metal part) 3 having an elliptical cross section is formed. By forming such a nugget 3, the two steel plates 1A and 1B are welded. Alternatively, as shown in FIG. 2, three steel plates 1A, 1B, and 1C are overlapped and energized while pressing the electrodes 2A and 2B in the same manner as described above, thereby nuggets (melted) between the three steel plates 1A to 1C.
- the three steel plates 1A to 1C are welded.
- the three steel plates 1A, 1B, and 1C are both high-strength steel plates, or two are high-strength steel plates, and the outer one (steel plate 1A) is a low-strength steel plate (tensile strength less than 780 MPa).
- the steel plates 1A to 1C may be simply referred to as the steel plate 1 for convenience.
- the energization pattern in which the pressure applied by electrodes 2A and 2B, pre-energization to main energization (welding energization), and post-energization is applied is defined within the appropriate range as described below To do. Thereby, it is possible to prevent the occurrence of scattering while suppressing the occurrence of indentation, and to form a highly reliable welded portion having a sufficiently high strength with good workability. .
- spot welding is a first energization step that is a pre-energization of the welding pressure P1 (kN) and the welding current I1 (kA), and a book of the welding pressure P2 (kN) and the welding current I2 (kA). It consists of the 2nd electricity supply process which is electricity supply.
- the welding current I1 is set to a range of 30% or more and 90% or less (hereinafter referred to as 30 to 90%) of the welding current I2. Furthermore, after the first energization process is completed, the second energization process is started within 0.1 (s).
- the steel plate 1 as the work piece includes two or more high-strength steel plates each having a tensile strength of 780 to 1850 MPa.
- the strength of the steel sheet has a great influence on the stress concentration state in the welded portion, and therefore has an influence on the deterioration of the fracture form, the accompanying strength variation, and the strength reduction. If the tensile strength of the steel sheet is less than 780 MPa, these problems are unlikely to occur, and if it exceeds 1850 MPa, it is difficult to improve the joint strength in order to prevent a decrease or variation in joint strength.
- the tensile strength is in the range of 780 to 1850 MPa and the high-strength steel plate capable of reducing the weight and improving the collision safety is included.
- high strength and, in some cases, high carbon equivalent are fundamental in order to ensure both strength and formability.
- hard martensite is formed in the weld metal portion and the heat affected zone. If the heat-affected zone around the weld metal part is hard and the strength of the base metal is high, deformation of the heat-affected zone and the surrounding base metal is difficult to occur, and stress concentration tends to occur on the weld metal part.
- the steel plate characteristics are defined in the conditions described below, and then spot welding is performed under each welding condition described in detail later.
- spot welding is performed under each welding condition described in detail later.
- Step grade There are no particular limitations on the type of steel sheet 1 to be welded.
- a two-phase structure type for example, a structure containing martensite in ferrite, a structure containing bainite in ferrite, etc.
- a work-induced transformation type ferrite
- Any type of steel sheet may be used such as a structure containing retained austenite), a quenching type (martensitic structure), a fine crystal type (ferrite main structure), and the like.
- High-strength steel sheets can be welded while being suppressed. As a result, a highly reliable spot-welded joint (welded portion) is obtained with a good fracture form, less variation in strength and lowering.
- plating With respect to the type of plating layer applied to the surface layer of the steel sheet 1 that is the workpiece, for example, Zn-based, Zn-Fe-based, Zn-Ni-based, Zn-Al-based, Zn-Mg-based, Pb-Sn-based, Any plating layer such as Sn—Zn and Al—Si may be used. Further, an inorganic or organic film (for example, a lubricating film) may be applied to the surface layer of the plating layer. Also, the basis weight of these plating layers is not particularly limited, but the basis weight on both sides is preferably 100 (g / m 2 ) / 100 g / m 2 ) or less. If the amount of plating exceeds 100 (g / m 2 ) per side, the plating layer may become an obstacle during welding.
- the plate thickness of the steel plate 1 to be welded is not particularly limited, and is a common plate thickness used in the field of automobile bodies, for example, a steel plate having a plate thickness of about 0.6 to 3.2 (mm). If so, the above effect can be stably obtained by applying the present invention. However, since the stress concentration at the welded portion increases as the plate thickness increases, the plate thickness of the steel plate 1 is more preferably in the range of 0.6 to 2.0 (mm).
- the energization pattern at the time of carrying out resistance spot welding of the steel plate 1 demonstrated below is shown in the graph of FIG.
- the energization pattern shown in FIG. 3 is an example of an energization pattern applicable to the spot welding method of the present invention.
- the vertical axis represents the welding currents I1 and I2 or the applied pressure P
- the horizontal axis represents the time T.
- the second energization process is performed immediately after the first energization process, or the second energization process is performed after the energization stop time within 0.1 (s).
- the welding current I1 in the first energization process is set lower than the welding current I2 in the second energization process.
- the current represents an effective value in the case of an AC power supply.
- the pressure P applied by the electrodes 2A and 2B is constant throughout the first energization process and the second energization process, and is also applied during the energization stop time between the first energization process and the second energization process. It is in a state.
- the rising pattern of the welding current I1 when starting the first energization process may be a pattern for raising the welding current I1 to a vertically set as shown in the graph of FIG. 3, or an up slope.
- a pattern (a stepwise pattern in which the current is gradually increased) may be used.
- the applied pressure P of the electrodes 2A and 2B has a great influence on the strength of the welded portion accompanying the occurrence of indentation, particularly the strength change in the peeling direction, as well as the occurrence of defects and cracks in the weld metal (nugget). . Therefore, as represented by the above formula (1), first, the upper limit of the pressing force P is limited as described above based on the average thickness t of the plurality of steel plates 1, and the pressing force is not too high. Indentation is suppressed from occurring on the surface of the steel plate 1. On the other hand, even if the applied pressure P is too low, scattering may occur during spot welding. Therefore, the lower limit of the applied pressure P that can suppress the generation of the scattered is set to 0.5 (kN).
- the applied pressure P exceeds the upper limit of the above range, the surface of the steel sheet 1 is recessed by the electrodes 2A and 2B, so that a large indentation is generated, the joint strength is lowered, and the appearance is impaired. . Further, when the applied pressure P is below the lower limit of the above range, the contact area is reduced, the current density is increased, and scattering is likely to occur, and the nugget size (joint area) is reduced or dispersed. Decrease in strength or variation occurs.
- the pressure P applied by the electrodes 2A and 2B is in the above range, and is defined in a range lower than a general pressure. Then, as will be described in detail later, by performing the first energization step (pre-energization) before the second energization step (main energization), the electrodes 2A and 2B can be suppressed while suppressing the occurrence of scattering with a lower welding current. And the steel plate 1 are made to conform to each other, and after each steel plate 1 is made to conform to each other, a pattern in which main energization is performed by the second energization process is adopted.
- the welding current I1 (kA) in the first energization process which is the pre-energization, is defined in the range of 30 to 90% of the welding current I2 (kA) in the second energization process, which is the main energization.
- the energization pattern is divided into a first energization process that is pre-energization and a second energization process that is main energization, and the welding current I1 in the first energization process is changed to the welding current in the second energization process. It is lower than I2.
- the second energization process which has a higher welding current I2 than the first energization process, it is possible to ensure a sufficient bonding area by sufficiently melting the base material.
- the pre-energization at a low current in the first energization step makes the electrodes 2A, 2B and the steel plate 1 become familiar, and the steel plates 1 become familiar, and the contact area is sufficiently secured.
- the occurrence of scattering can also be suppressed in the two energization process.
- the electrodes 2A and 2B and the steel plate 1 are familiarized by pre-energization and the steel plates 1 are adapted to each other. It becomes difficult to obtain the effect.
- the welding current I1 in the first energization process exceeds 90% with respect to the welding current I2 in the second energization process, the current density at the joint becomes high and scattering may occur.
- the second energization process as the main energization is started within 0.1 (s). That is, a pattern in which the second energization process is performed immediately after the first energization process or the second energization process is performed after the energization stop time within 0.1 (s) can be adopted.
- the energization stop time from the end of the first energization process to the start of the second energization process exceeds 0.1 (s)
- the preheating effect due to the pre-energization in the first energization process is lost.
- the pause time is as short as possible, and it is more preferable that there is no pause time between the first energization step and the second energization step.
- the upper limit of the energization pause time, 0.1 (s) is, for example, a pause time of 5 cycles (0.1 (s)) when a commercial power supply of 50 Hz is used as the power source of the welding machine, and 60 Hz When the commercial power source is used, the suspension time is 6 cycles (0.1 (s)).
- the 2nd electricity supply process is started immediately after a 1st electricity supply process, or the method of providing the electricity supply stop time below 0.1 (s) as mentioned above is demonstrated, it is limited to this. Not.
- an upslope pattern that gradually increases the current between the first energization process and the second energization process may be used.
- Specific numerical values such as the welding current and energization time are not particularly limited, and may be set to the same level as the current value and energization time conventionally employed in the resistance spot welding method for welding steel plates.
- a conventionally known resistance spot welding equipment provided with electrodes 2A and 2B as illustrated in FIG. 1 can be employed without any limitation.
- the power source that supplies current to the electrodes 2A and 2B may be either an AC power source, a DC inverter, or an AC inverter.
- the size and shape of the electrodes 2A and 2B are not particularly limited, but it is preferable to use electrodes having an electrode tip diameter of about 6 to 8 (mm) in order to obtain an appropriate surface pressure at the electrode tip.
- the pressure P of the electrodes 2A and 2B is set to the average plate thickness of the steel plate 1.
- the applied pressure P not too high, it is possible to suppress the occurrence of indentation in the steel sheet 1 and to make the lower limit of the applied pressure P appropriate, thereby generating the scattering. Can be prevented.
- the pre-energization in the first energization process under the above conditions the nugget diameter is ensured while suppressing the occurrence of indentation, and sufficient joint strength is obtained.
- the spot welding method of the high-strength steel plate according to the second embodiment is a method of welding two steel plates 1A and 1B or three steel plates 1A to 1C by resistance spot welding as in the first embodiment.
- the applied pressure of the electrodes 2A and 2B in the first energization process when at least one of the overlapped steel plates 1 before spot welding (hereinafter simply referred to as a gap) is 0.5 (mm) or more.
- the point which changes the applied pressure in a 2nd electricity supply process differs from the said 1st Embodiment.
- the spot welding is a first energization step that is a pre-energization of the welding pressure P1 (kN) and the welding current I1 (kA), and a book of the welding pressure P2 (kN) and the welding current I2 (kA). It consists of the 2nd electricity supply process which is electricity supply.
- the pressures P1 and P2 are set to ranges represented by the following formulas (2) and (3) when the average plate thickness of the plurality of steel plates 1 is t (mm). 0.5 ⁇ P2 ⁇ 3.0t (1/3) (2) 1.0 ⁇ P2 ⁇ P1 ⁇ 2.0 ⁇ P2 (3)
- the welding current I1 is set in a range of 30 to 90% of the welding current I2. Furthermore, after the first energization process is completed, the second energization process is started within 0.1 (s).
- the applied pressure P1 is higher than that in the second energization process that is main energization.
- the high-strength steel sheet 1 is pressurized with a pressure P1 that is more than 1.0 times and less than 2.0 times P2.
- the welding current is set to the same condition as the welding current I1 (kA) in the first energization process described in the first embodiment.
- the same applied pressure as the applied pressure P in the first embodiment that is, the application of the range represented by the following expression ⁇ 0.5 ⁇ P2 ⁇ 3.0t (1/3) ⁇
- the main energization is performed at the pressure P2 and the welding current I2 under the same conditions as described above.
- the second energization process is defined under the same conditions as in the first embodiment.
- a method of performing the second energization process after performing the pre-energization in the first energization process with a high pressure P1 is adopted.
- the contact area between the electrodes 2A and 2B and the steel plate 1 is sufficiently ensured in the first energization process, and the occurrence of scattering is suppressed in the subsequent second energization process, while the base material is melted in the second energization process. As a result, sufficient bonding area can be secured.
- the energization pattern of the second embodiment is the same as the energization pattern of the first embodiment. Then, as shown in the graph of FIG. 4, in the first energization process and the energization stop time, the applied pressure by the electrodes 2A and 2B is set to a higher applied pressure P1 than the applied pressure P2 in the subsequent second energized process. A pressure pattern is used.
- the pressurizing force P1 in the first energizing step is less than the lower limit defined by the above formula (3), that is, 1.0 times or less of the pressurizing force P2 in the second energizing step, as described above, It is difficult to obtain the effect of securing the contact area between the steel plates 1 having gaps between them. Further, if the applied pressure P1 exceeds the upper limit defined by the above equation (3), that is, 2.0 times the applied pressure P2 in the second energization process, the welding current I1 in the first energization process is low and the applied pressure is increased.
- the base material in the second energization step is sufficiently melted, and the bonding area and the nugget diameter are ensured. be able to.
- the applied pressure P2 in the second energization step is outside the range defined by the above equation (2), the same problem as described in the first embodiment may occur.
- the dimension of the clearance gap between the steel plates 1 was 0.5 (mm) or more, this is a dimension comparable to the general clearance produced in the assembly process of the vehicle body etc. of a motor vehicle.
- the upper limit of the clearance gap between the steel plates 1 is not specifically limited, As for the clearance gap which arises in the said process, about 2.0 (mm) is generally the maximum value.
- the clearance gap between each steel plate 1 is less than 0.5 (mm), sufficient effect of joint strength improvement is acquired by applying each condition in the said 1st Embodiment.
- the first energization process and the second energization process when at least one of the gaps in the steel sheet 1 is 0.5 (mm) or more.
- the spot welding method of the high-strength steel sheet according to the third embodiment has the third energization process under the following conditions after the completion of the second energization process, which is the main energization, in obtaining the spot welded joint 10.
- a third energization process that is post-energization is provided after the second energization process that is main energization.
- the welding current is I3 (kA)
- the energization time is T3 (s)
- the non-energization time between the second energization process and the third energization process is TC (s).
- the welding current I3 is in the range of 3 (kA) to 15 (kA) (hereinafter referred to as 3 to 15 (kA)).
- the non-energization time TC is set in a range of 0 (s) or more and 0.2 (s) or less (hereinafter referred to as 0 to 0.2 (s)).
- the relationship between the welding current I3 and the energization time T3 is set to a range represented by the following equation (4). I3 ⁇ T3 ⁇ 0.7 + TC (4)
- the pressurizing force of the electrodes 2A and 2B can be the same as the pattern (pressing force P) in the first embodiment or the pattern (pressing force P1, P2) in the second embodiment.
- the pressurizing force in the third energizing step is the pressurizing force in the previous second energizing step, that is, the pressurizing pressure P in the first embodiment,
- the pressure can be the same as the pressure P2 in the second embodiment.
- the graph of FIG. 5 shows the relationship between the energization pattern and the pressure pattern in the third embodiment.
- the pressure pattern is the same pattern as in the first embodiment, that is, after a constant pressure P is applied in the first energization process, the energization pause time, and the second energization process. Furthermore, the pressure P is constant in the subsequent non-energization time and the third energization process.
- the first energization process, the energization stop time, and the second energization process are the same patterns as in the first embodiment and the second embodiment, and then the non-energization time ( TC) and a third energization step are provided.
- the welding current I3 is defined in the range of 3 to 15 (kA). This welding current I3 has a particularly great influence on the structure of the weld metal part and the heat-affected part and the segregation state. By setting the welding current I3 in the third energization step within this range, the effect of improving joint strength by multi-stage energization can be obtained more remarkably. If the welding current I3 in the third energization step is less than 3 (kA), it is difficult to obtain the effect of improving joint strength by post-energization, and if it exceeds 15 (kA), scattering tends to occur and the above effect is obtained. It will be reduced.
- the non-energization time TC between the second energization process and the third energization process is in the range of 0 to 0.2 (s), that is, immediately after the second energization process is completed, the third energization process is performed.
- the process is started, or after the completion of the second energization process, a condition is set such that the third energization process is started within 0.2 (s).
- the non-energization time TC within the above range, the effect of improving the joint strength by post-energization can be obtained more remarkably.
- the non-energization time TC in the third energization process exceeds 0.2 (s)
- the process time becomes longer and the productivity is lowered, and the effect of improving the joint strength by post-energization may be reduced. There is.
- a pattern is described in which the third energization process is started immediately after the second energization process is completed, or the third energization process is started within a predetermined time. It is not limited to. For example, a down slope pattern in which the current is gradually decreased can be formed between the second energization process and the third energization process.
- the energization time T3 (s) of the third energization process is not particularly limited in the range as an absolute value, but is defined by a calculated value obtained by multiplying the above-described welding current I3.
- the energization time T3 has a particularly great influence on the weld metal, the structure of the heat-affected zone, and the segregation state, similarly to the welding current I3.
- the pressure P of the electrodes 2A and 2B is set to an appropriate range according to the average thickness t of the steel plate 1, and the first energization step (pre-energization step) ) And the second energization process (main energization) are optimally controlled, so that the nugget diameter can be secured while the occurrence of indentation is suppressed, and the occurrence of scattering can be prevented. Thereby, it is possible to form the spot welded joint 10 having high reliability and excellent joint strength while maintaining good workability.
- the applied pressure P1 in the first energization process which is the pre-energization
- the applied pressure P2 in the second energization process which is the main energization
- at least one of the gaps in the steel sheet 1 is 0.5 ( mm) or more, the gap can be filled and the contact area can be secured, a sufficient joint area can be secured, and the occurrence of scattering during welding can be effectively prevented. Thereby, it becomes possible to obtain the spot welded joint 10 excellent in joint strength with good workability.
- the spot-welded joint 10 in which the joint strength is further improved by including the third energization step that is post-energization in which the non-energization time TC, the welding current I3, and the energization time T3 are optimized. . Therefore, for example, in the process of manufacturing automobile parts, assembling the vehicle body, etc., it is possible to fully enjoy the merits of reducing fuel consumption and reducing carbon dioxide (CO 2 ) emissions by reducing the weight of the entire vehicle body. The social contribution is immeasurable.
- CO 2 carbon dioxide
- the present invention will be described in more detail by giving examples of the spot welding method for high-strength steel sheets according to the present invention.
- the present invention is not limited to the following examples, and can be implemented with appropriate modifications within a range that can be adapted to the purpose described above and below. It is included in the technical scope.
- Example 1 is for demonstrating 1st Embodiment. Using a steel plate of the plate thickness and steel type as shown in FIG. 7, a 40 ⁇ 40 (mm) structure observation specimen was prepared. Among the steel types shown in FIG. 7, CR1470HP and CR1780HP indicate hot press (hot stamping) steel sheets disclosed in Japanese Patent Laid-Open No. 2000-234153. GA1180Y indicates a Japan Iron and Steel Federation standard product (JAC1180Y). CR980Y indicates JSC980Y of the Japan Iron and Steel Federation standard product, and CR270D indicates JSC270D. In addition, CR means a cold rolled steel sheet and GA means an alloyed galvanized steel sheet.
- a cross tensile test piece was prepared based on the cross tension test method (JIS Z3137) for resistance spot welded joints.
- the test pieces were overlapped in a cross shape as shown in FIGS. 6A and 6B, and the conditions shown in FIG. Spot welding was performed to prepare a cross tensile test piece.
- Three cross tension test pieces were produced under the same conditions. Then, as indicated by reference numeral 6 in FIGS. 6A and 6B, the load is applied in the direction in which the upper test piece is in the upward direction and the lower test piece is in the downward direction, and in the direction in which they are peeled from each other.
- a cross tensile test was carried out to measure the cross tensile strength (CTS).
- the cross tensile strength should be 2.5 (kN) or more. It can be said that it has sufficient CTS.
- the thickness t of the thinnest steel plate is 1.0 (mm), 1.6 (mm), and 2.0 (mm)
- the cross tensile strength is 5 (kN) and 9 (kN), respectively.
- 11 (kN) or more it can be said that it has sufficient CTS.
- FIG. 7 shows a list of production conditions and test results for each test piece.
- Example 1 is for demonstrating 1st Embodiment, and pressurizing force P1 and P2 are made into the same numerical value (pressing force P) in each condition number.
- Condition Nos. 1 to 5 are examples in which two or three CR1470HPs having a plate thickness of 1.0 (mm) are spot welded.
- condition numbers 2 to 4 are examples of the present invention in which spot welding is performed under the spot welding conditions within the range described in the first embodiment.
- Condition number 4 is an example in which spot welding was performed with three high-strength steel plates stacked.
- condition numbers 1 and 5 are comparative examples in which spot welding is performed under spot welding conditions outside the range described in the first embodiment.
- Condition Nos. 6 to 8 are examples in which two GA1180Y plates having a thickness of 2.0 (mm) are overlapped and spot-welded.
- Condition No. 7 is an example of the present invention in which spot welding is performed under the spot welding conditions within the range described in the first embodiment.
- condition numbers 6 and 8 are comparative examples in which spot welding was performed under spot welding conditions outside the range described in the first embodiment.
- Condition Nos. 9 to 11 are examples in which two sheets of CR1780HP having a plate thickness of 1.0 (mm) are overlapped and spot-welded.
- the condition number 10 is an example of the present invention in which spot welding is performed under the spot welding conditions within the range described in the first embodiment.
- condition numbers 9 and 11 are comparative examples in which spot welding was performed under spot welding conditions outside the range described in the first embodiment. Specifically, it is outside the condition that the welding current I1 is in the range of 30 to 90% of the welding current I2.
- Condition numbers 12 to 14 are examples in which two CR980Y plates having a thickness of 0.7 (mm) are overlapped and spot-welded.
- Condition No. 13 is an example of the present invention in which spot welding is performed under the spot welding conditions within the range described in the first embodiment.
- condition numbers 12 and 14 are comparative examples in which spot welding was performed under spot welding conditions outside the range described in the first embodiment.
- Condition number 15 is an example in which two sheets of CR980Y having a thickness of 0.7 (mm) and CR980Y having a thickness of 4.0 (mm) are overlapped and spot-welded, but there is a difference in the thickness. After that, joining itself was impossible.
- Condition Nos. 16 to 18 are examples in which two CR980Y plates having a thickness of 1.6 (mm) and two CR980D plates having a thickness of 0.7 (mm) on the outside are overlapped and spot-welded. It is.
- condition number 17 is an example of the present invention in which spot welding is performed under the spot welding conditions within the range described in the first embodiment.
- condition numbers 16 and 18 are comparative examples in which spot welding was performed under spot welding conditions outside the range described in the first embodiment.
- the maximum indentation depth is 0. It was confirmed that the nugget diameter was all secured at 4.2 (mm) or more.
- the cross tensile strength (CTS) by the cross tension test is 2.5 (kN) or more when the thickness t is 0.7 (mm), and the thickness t is 1 (mm). In this case, 5.0 (kN) or more, 10 (kN) or more when the thickness t is 1.6 (mm), and 11 (kN) or more when the thickness t is 2.0 (mm). It was revealed that the joint strength was excellent. Moreover, in the example of this invention, it has confirmed that there was no scattering by visual observation at the time of spot welding.
- condition numbers 1-5 6, 8, 9, 11, 12, 14, 16, and 18 it was confirmed that the nugget diameter tends to decrease while the indentation depth increases. . Further, in the comparative example, the cross tensile strength (CTS) was lower than that of the present invention example, and it was revealed that the joint strength was inferior. In condition numbers 16 to 18, the nugget diameter was measured at the plate interface of CR980Y, which is a high-strength steel plate. Further, the cross tensile strength (CTS) was also measured by pulling the CR980Y apart, that is, the strength of the welded portion between the CR980Y.
- CTS cross tensile strength
- the applied pressure P is 0.4 (kN), which is lower than the range defined in the first embodiment. Therefore, in comparison with the inventive examples 2 and 3, the nugget diameter is 3. It was as small as 1 (mm), and the indentation depth was as large as 0.4 (mm). For this reason, in condition number 1, the cross tensile strength was 2.1 (kN) and the joint strength was low. Moreover, in the condition number 1, since the pressurizing force P was low, it was confirmed that scattering occurred by visual observation during spot welding.
- condition number 5 since the applied pressure P exceeds 4.0 (kN) and the range defined in the first embodiment, the nugget diameter in comparison with the inventive examples 2 and 3 is Although 5.3 (mm) was sufficient, the indentation depth was as large as 0.3 (mm). For this reason, in condition number 5, the cross tensile strength was 3.5 (kN) and the joint strength was low.
- condition number 6 the applied pressure P is 0.4 (kN), which is less than the range defined in the first embodiment, and therefore, in comparison with the inventive example 7, the nugget diameter is 5. It was as small as 5 (mm) and the indentation depth was as large as 0.3 (mm). For this reason, in condition number 6, the cross tensile strength was 7.0 (kN) and the joint strength was low. Further, in condition number 6, occurrence of scattering was confirmed.
- condition number 8 the applied pressure P is 4.5 (kN), which exceeds the range defined in the first embodiment, and therefore the nugget diameter is 6. 7 (mm) was sufficient, but the indentation depth was as large as 0.3 (mm). For this reason, in condition number 8, the cross tensile strength was 6.2 (kN) and the joint strength was low.
- condition number 9 since the welding current I1 is less than 30% of the welding current I2, in comparison with the inventive example 10, the nugget diameter is as small as 4.4 (mm). The depth of the station became as large as 0.3 (mm). For this reason, in condition number 9, the cross tensile strength was 4.1 (kN) and the joint strength was low. In condition number 9, the occurrence of scattering was confirmed.
- condition number 11 since the welding current I1 exceeds 90% of the welding current I2, in comparison with the inventive example 10, the nugget diameter was 4.9 (mm), which was sufficient. The depth of indentation was as large as 0.3 (mm). For this reason, in condition number 11, the cross tensile strength was 4.2 (kN) and the joint strength was low.
- condition number 12 the applied pressure P is 0.4 (kN), which is lower than the range defined in the first embodiment. Therefore, in comparison with the inventive example 13, the nugget diameter is 3.3 ( mm) and the indentation depth was as large as 0.3 (mm). For this reason, in condition number 12, the cross tensile strength was 2.0 (kN) and the joint strength was low. In addition, in condition number 12, occurrence of scattering was confirmed.
- the applied pressure P is 3.5 (kN), which exceeds the range defined in the first embodiment, and therefore, in comparison with the inventive example 13, the nugget diameter is 4. 4 (mm) was sufficient, but the indentation depth was as large as 0.2 (mm). For this reason, in condition number 14, the cross tensile strength was 1.9 (kN) and the joint strength was low.
- condition number 16 the applied pressure P is 0.3 (kN), which is lower than the range defined in the first embodiment. Therefore, in comparison with the inventive example 17, the nugget diameter is 5.2 ( mm) and the indentation depth was as large as 0.3 (mm). For this reason, in condition number 16, the cross tensile strength was 6.8 (kN) and the joint strength was low. Further, in condition number 16, occurrence of scattering was confirmed.
- condition number 18 since the applied pressure P exceeds 5.0 (kN) and the range prescribed
- Example 2 is for demonstrating 2nd Embodiment.
- a structure observation test piece and a cross tensile test piece were prepared in the same procedure as in Example 1, and various tests were performed in the same manner.
- the overlapping gap between the steel plates 1 was set by sandwiching a spacer steel plate having a thickness corresponding to a predetermined gap between the steel plates 1 to be evaluated for welding.
- the spacer steel plates 11 were arranged on both outer sides of the welded portion evaluated with an interval of 40 mm, and a predetermined gap was secured between the steel plates 1.
- FIG. 8 shows a list of production conditions and test results for each test piece.
- Example 2 is for demonstrating 2nd Embodiment, and sets the applied pressure P1 in a 1st electricity supply process (pre-energization) and the applied pressure P2 in a 2nd electricity supply process (main electricity supply) as a different numerical value. Yes.
- Condition Nos. 21 to 26 are examples in which two or three CR1470HPs having a plate thickness of 1.0 (mm) are overlapped and spot welded.
- condition numbers 22 and 25 are examples of the present invention in which spot welding is performed under the spot welding conditions within the range described in the second embodiment.
- condition numbers 21, 23, 24, and 26 are comparative examples in which spot welding was performed under spot welding conditions outside the range described in the second embodiment.
- the relationship between the applied pressures P1 and P2 is out of the range represented by the above equation (3).
- Condition numbers 27 to 29 are examples in which two GA1180Y plates having a thickness of 2.0 (mm) are overlapped and spot welded.
- condition number 28 is an example of the present invention in which spot welding is performed under the spot welding conditions within the range described in the second embodiment.
- condition numbers 27 and 29 are comparative examples in which spot welding was performed under spot welding conditions outside the range described in the second embodiment.
- the relationship between the applied pressures P1 and P2 is out of the range represented by the above equation (3).
- Condition numbers 30 to 32 are examples in which two sheets of CR1780HP having a plate thickness of 1.0 (mm) are overlapped and spot-welded.
- condition number 31 is an example of the present invention in which spot welding is performed under the spot welding conditions within the range described in the second embodiment.
- condition numbers 30 and 32 are comparative examples in which spot welding was performed under spot welding conditions outside the range described in the second embodiment.
- the relationship between the applied pressures P1 and P2 is out of the range represented by the above equation (3).
- Condition numbers 33 to 35 are examples in which two sheets of CR980Y having a thickness of 0.7 (mm) are overlapped and spot-welded.
- condition number 34 is an example of the present invention in which spot welding is performed under the spot welding conditions within the range described in the second embodiment.
- condition numbers 33 and 35 are comparative examples in which spot welding was performed under spot welding conditions outside the range described in the second embodiment.
- the relationship between the applied pressures P1 and P2 is out of the range represented by the above equation (3).
- Condition Nos. 36 to 38 are examples in which two CR980Y plates having a thickness of 1.6 (mm) and two CR980D plates having a thickness of 0.7 (mm) on the outside are overlapped and spot welded. It is.
- condition number 37 is an example of the present invention in which spot welding is performed under the spot welding conditions within the range described in the second embodiment.
- condition numbers 36 and 38 are comparative examples in which spot welding is performed under spot welding conditions outside the range described in the second embodiment.
- the relationship between the applied pressures P1 and P2 is out of the range represented by the above equation (3).
- the indentation depth is 0.2 (maximum) regardless of the steel type used. It was confirmed that the nugget diameter was all secured at 4.2 (mm) or more.
- the cross tensile strength (CTS) by the cross tension test is 2.5 (kN) or more when the thickness t is 0.7 (mm), and the thickness t is 1 (mm). In this case, 5.0 (kN) or more, 10 (kN) or more when the thickness t is 1.6 (mm), and 11 (kN) or more when the thickness t is 2.0 (mm). It was revealed that the joint strength was excellent. Moreover, in the example of this invention, it has confirmed that there was no scattering by visual observation at the time of spot welding.
- condition numbers 21, 23, 24, 26, 27, 29, 30, 32, 33, 35, 36, and 38 the nugget diameter tends to decrease while the indentation depth increases.
- the cross tensile strength (CTS) was lower than that of the present invention example, and it was revealed that the joint strength was inferior.
- the nugget diameter was measured at the plate interface of CR980Y, which is a high-strength steel plate.
- the cross tensile strength (CTS) was also measured by pulling the CR980Y apart, that is, the strength of the welded portion between the CR980Y.
- the pressure ratio P1 / P2 is 1.0, which is lower than the range described in the second embodiment. Therefore, in comparison with the inventive example 22, the nugget diameter is 3.2 ( mm) and the indentation depth was as large as 0.3 (mm). For this reason, in condition number 21, the cross tensile strength was 2.4 (kN) and the joint strength was low. In addition, in condition number 21, occurrence of scattering was confirmed.
- the pressure ratio P1 / P2 is 2.4, which exceeds the range described in the second embodiment, and therefore, in comparison with the inventive example 22, the nugget diameter is 4. It was as small as 7 (mm), and the indentation depth was as large as 0.2 (mm). For this reason, in condition number 23, the cross tensile strength was 4.2 (kN) and the joint strength was low. In addition, in condition number 23, occurrence of scattering was confirmed.
- condition number 24 the pressure ratio P1 / P2 is 1.0, which is lower than the range described in the second embodiment. Therefore, in comparison with the inventive example 25, the nugget diameter is 3.0 ( mm) and the indentation depth was as large as 0.4 (mm). For this reason, in condition number 24, the cross tensile strength was 3.6 (kN) and the joint strength was low. Further, in condition number 24, occurrence of scattering was confirmed.
- the pressure ratio P1 / P2 is 2.2, which exceeds the range described in the second embodiment, and therefore, in comparison with the inventive example 25, the nugget diameter is 4. It was as small as 3 (mm), and the indentation depth was as large as 0.4 (mm). For this reason, in condition number 26, the cross tensile strength was 3.7 (kN) and the joint strength was low. Moreover, in the condition number 26, occurrence of scattering was confirmed.
- the pressure ratio P1 / P2 is 1.0, which is lower than the range described in the second embodiment. Therefore, in comparison with the inventive example 28, the nugget diameter is 3.7 ( mm) and the indentation depth was as large as 0.4 (mm). For this reason, in condition number 27, the cross tensile strength was 5.5 (kN) and the joint strength was low. Further, in condition number 27, the occurrence of scattering was confirmed.
- condition number 29 the pressure ratio P1 / P2 is 2.7, which exceeds the range described in the second embodiment, so the nugget diameter is 5. It was as small as 0 (mm) and the depth of indentation was as large as 0.4 (mm). For this reason, in condition number 29, the cross tensile strength was 7.5 (kN) and the joint strength was low. Further, in condition number 29, occurrence of scattering was confirmed.
- the pressing force ratio P1 / P2 is 1.0, which is lower than the range described in the second embodiment. Therefore, in comparison with the inventive example 31, the nugget diameter is 3.9 ( mm) and the indentation depth was as large as 0.4 (mm). For this reason, in condition number 30, the cross tensile strength was 4.1 (kN) and the joint strength was low. In addition, in condition number 30, occurrence of scattering was confirmed.
- the pressure ratio P1 / P2 is 2.2, which exceeds the range described in the second embodiment, so that the nugget diameter is 4 in comparison with the inventive example 31. It was as small as 7 (mm), and the indentation depth was as large as 0.3 (mm). For this reason, in condition number 32, the cross tensile strength was 4.8 (kN) and the joint strength was low. In addition, in condition number 32, occurrence of scattering was confirmed.
- condition number 33 the pressure ratio P1 / P2 is 1.0, which is lower than the range described in the second embodiment. Therefore, in comparison with the inventive example 34, the nugget diameter is 3.9 ( mm) and the indentation depth was as large as 0.2 (mm). For this reason, in condition number 33, the cross tensile strength was 1.9 (kN) and the joint strength was low. In addition, in condition number 33, occurrence of scattering was confirmed.
- the pressure ratio P1 / P2 is 2.4, which exceeds the range described in the second embodiment, so that the nugget diameter is 3. It was as small as 5 (mm) and the depth of indentation was as large as 0.3 (mm). For this reason, in condition number 35, the cross tensile strength was 1.7 (kN) and the joint strength was low. In addition, in condition number 35, occurrence of scattering was confirmed.
- the pressing force ratio P1 / P2 is 1.0, which is lower than the range described in the second embodiment. Therefore, in comparison with the inventive example 37, the nugget diameter is 5.3 ( mm) and the indentation depth was as large as 0.2 (mm). For this reason, in condition number 36, the cross tensile strength was 6.9 (kN) and the joint strength was low. Further, in the condition number 36, occurrence of scattering was confirmed.
- the pressure ratio P1 / P2 is 2.2, which exceeds the range described in the second embodiment, and therefore, in comparison with the inventive example 37, the nugget diameter is 5. It was as small as 2 (mm) and the indentation depth was as large as 0.2 (mm). For this reason, in condition number 38, the cross tensile strength was 7.2 (kN) and the joint strength was low. Further, in the condition number 38, occurrence of scattering was confirmed.
- Example 3 is for demonstrating the case where it has the 3rd electricity supply process which is a post-energization after the 2nd electricity supply process in 1st Embodiment among 3rd Embodiment.
- a structure observation test piece and a cross tensile test piece were prepared in the same procedure as in Example 1, and various tests were performed in the same manner.
- FIG. 9 shows a list of production conditions and test results for each test piece.
- Example 3 is for demonstrating the third embodiment. In the first energization process and the second energization process, the spot welding conditions within the range described in the first embodiment are satisfied.
- Condition Nos. 41 to 45 are examples in which two sheets of CR1470HP having a plate thickness of 1.0 (mm) are overlapped and spot-welded.
- condition numbers 41, 42, and 45 are examples of the present invention in which spot welding is performed under the spot welding conditions within the range described in the third embodiment.
- condition numbers 43 and 44 are comparative examples in which spot welding was performed under spot welding conditions outside the range described in the third embodiment. Specifically, by changing the non-energization time TC, the welding current I3 and the energization time T3 in the third energization process, the left side-right side of the equation (4) exceeds zero.
- Condition Nos. 46 to 49 are examples in which three sheets of CR1470HP having a plate thickness of 1.0 (mm) are overlapped and spot-welded.
- condition numbers 46 and 47 are examples of the present invention in which spot welding is performed under the spot welding conditions within the range described in the third embodiment.
- condition numbers 48 and 49 are comparative examples in which spot welding was performed under spot welding conditions outside the range described in the third embodiment. Specifically, by changing the non-energization time TC, the welding current I3 and the energization time T3 in the third energization process, the left side-right side of the equation (4) exceeds zero.
- condition numbers 41, 42, and 45 to 47 the cross tensile strength (by the cross tension test) (compared to the comparative examples with condition numbers 43, 44, 48, and 49) CTS) was found to be high.
- Condition numbers 41, 42, and 45 are the same as condition number 2 except for the presence / absence of the third energization step. However, in condition numbers 41, 42, and 45, the cross in the cross tension test is greater than condition number 2. It became clear that tensile strength (CTS) became high.
- Example 4 is for demonstrating the case where it has the 3rd electricity supply process which is a post-energization after the 2nd electricity supply process in 2nd Embodiment among 3rd Embodiment.
- a structure observation specimen and a cross tensile specimen were prepared in the same procedure as in Example 1, and various tests were performed in the same manner.
- FIG. 10 shows a list of production conditions and test results for each test piece.
- Example 4 is for demonstrating 3rd Embodiment, and shall satisfy the spot-welding conditions in the range demonstrated by 2nd Embodiment in a 1st electricity supply process and a 2nd electricity supply process.
- Condition numbers 51 to 55 are examples in which two sheets of CR1470HP having a plate thickness of 1.0 (mm) are overlapped and spot-welded.
- condition numbers 51, 52, and 55 are examples of the present invention in which spot welding is performed under the spot welding conditions within the range described in the third embodiment.
- condition numbers 53 and 54 are comparative examples in which spot welding is performed under spot welding conditions outside the range described in the third embodiment. Specifically, by changing the non-energization time TC, the welding current I3 and the energization time T3 in the third energization process, the left side-right side of the equation (4) exceeds zero.
- Condition numbers 56 to 59 are examples in which three sheets of CR1470HP having a plate thickness of 1.0 (mm) are overlapped and spot-welded.
- condition numbers 56 and 57 are examples of the present invention in which spot welding was performed under the spot welding conditions within the range described in the third embodiment.
- condition numbers 58 and 59 are comparative examples in which spot welding was performed under spot welding conditions outside the range described in the third embodiment. Specifically, by changing the non-energization time TC, the welding current I3 and the energization time T3 in the third energization process, the left side-right side of the equation (4) exceeds zero.
- condition numbers 51, 52, 55 to 57 were found to be high.
- Condition numbers 51, 52, and 55 are the same as condition number 22 except for the presence or absence of the third energization step.
- CTS tensile strength
- condition numbers 56 and 57 and condition number 25 are the same conditions except for the presence or absence of the third energization step.
- condition numbers 56 and 57 the cross tensile strength by the cross tension test is larger than condition number 25. It became clear that (CTS) became high.
- the nugget diameter is secured while suppressing the occurrence of indentation, and the occurrence of scattering is prevented. Can do.
- This makes it possible to obtain a highly reliable welded joint having a sufficiently high strength with good workability. Therefore, by applying high-strength steel sheets in the automobile field, etc., it is possible to fully enjoy the merits of reducing fuel consumption and reducing carbon dioxide (CO 2 ) emissions associated with the weight reduction of the entire vehicle body. Contribution is immeasurable.
Abstract
Description
高強度鋼板をスポット溶接して形成させたスポット溶接継手の十字引張強さを向上させる方法として、溶接通電時において一定の条件下で2段通電、冷却を挟んだ2段通電、3段通電するスポット溶接方法が提案されている(例えば、特許文献1を参照)。
一方、散りの発生を抑制するために電極の加圧力を高めた場合には、大きなインデンテーションが発生して継手強度が低下するという問題があった。
即ち、本発明の要旨は以下のとおりである。
前記複数の鋼板は、
引張強さが共に780MPa以上、1850MPa以下である2枚の鋼板であって、板厚比={鋼板の板厚の総和}/{薄い側の鋼板の板厚(同厚の場合は1枚当たりの板厚)}が2以上、5以下の範囲となる2枚の鋼板である、
あるいは、引張強さが共に780MPa以上、1850MPa以下である3枚の鋼板、又は、引張強さが共に780MPa以上、1850MPa以下である2枚の鋼板とその外側の引張強さが780MPa未満である1枚の鋼板であって、板厚比={鋼板の板厚の総和}/{薄い側の鋼板の板厚(同厚の場合は1枚当たりの板厚)}が3以上、6以下の範囲となる3枚の鋼板であり、
前記スポット溶接は、加圧力P1(kN)、溶接電流I1(kA)の前通電である第1通電工程と、加圧力P2(kN)、溶接電流I2(kA)の本通電である第2通電工程とからなり、
前記加圧力P1、P2を、前記第1通電工程、前記第2通電工程を通して一定の加圧力P=P1=P2とするとともに、前記複数の鋼板の平均板厚をt(mm)とするとき、下記(1)式で表される範囲とし、
0.5≦P≦3.0t(1/3) ・・・(1)
前記溶接電流I1を、前記溶接電流I2の30%以上、90%以下の範囲とし、
前記第1通電工程が終了した後、0.1(s)以内に前記第2通電工程を開始することを特徴とする継手強度に優れた高強度鋼板のスポット溶接方法。
[2] 複数の鋼板を重ね合わせて抵抗スポット溶接する、継手強度に優れた高強度鋼板のスポット溶接方法であって、
前記複数の鋼板は、
引張強さが共に780MPa以上、1850MPa以下である2枚の鋼板であって、板厚比={鋼板の板厚の総和}/{薄い側の鋼板の板厚(同厚の場合は1枚当たりの板厚)}が2以上、5以下の範囲となる2枚の鋼板である、
あるいは、引張強さが共に780MPa以上、1850MPa以下である3枚の鋼板、又は、引張強さが共に780MPa以上、1850MPa以下である2枚の鋼板とその外側の引張強さが780MPa未満である1枚の鋼板であって、板厚比={鋼板の板厚の総和}/{薄い側の鋼板の板厚(同厚の場合は1枚当たりの板厚)}が3以上、6以下の範囲となる3枚の鋼板であり、
前記スポット溶接は、加圧力P1(kN)、溶接電流I1(kA)の前通電である第1通電工程と、加圧力P2(kN)、溶接電流I2(kA)の本通電である第2通電工程とからなり、
前記加圧力P1、P2を、前記複数の鋼板の平均板厚をt(mm)とするとき、下記(2)式、(3)式で表される範囲とし、
0.5≦P2≦3.0t(1/3) ・・・(2)
1.0×P2<P1≦2.0×P2 ・・・(3)
前記溶接電流I1を、前記溶接電流I2の30%以上、90%以下の範囲とし、
前記第1通電工程が終了した後、0.1(s)以内に前記第2通電工程を開始することを特徴とする継手強度に優れた高強度鋼板のスポット溶接方法。
[3] [1]に記載の継手強度に優れた高強度鋼板のスポット溶接方法において、前記重ね合わされた鋼板のスポット溶接前の隙間がいずれも0.5(mm)未満であることを特徴とする。
[4] [2]に記載の継手強度に優れた高強度鋼板のスポット溶接方法において、前記重ね合わされた鋼板のスポット溶接前の隙間のうち少なくとも1箇所が0.5(mm)以上であることを特徴とする。
[5] [1]又は[2]に記載の継手強度に優れた高強度鋼板のスポット溶接方法において、
本通電である前記第2通電工程の後に、後通電である第3通電工程を有し、
前記第3通電工程の溶接電流をI3(kA)とし、通電時間をT3(s)とし、前記第2通電工程と該第3通電工程との間の無通電時間をTC(s)で表したとき、
前記溶接電流I3を3(kA)以上、15(kA)以下の範囲とし、
前記無通電時間TCを0(s)以上、0.2(s)以内の範囲として、
前記溶接電流I3と前記通電時間T3との関係を下記(4)式で表される範囲とする
I3×T3≦0.7+TC ・・・(4)
ことを特徴とする。
図1、図2は、鋼板1を溶接するのに用いられる抵抗スポット溶接方法を説明するための模式図である。
図1に示すように、まず、被溶接材である2枚の鋼板1A、1B同士を重ね合わせる。2枚の鋼板1A、1Bは共に高強度鋼板である。そして、鋼板1A、1Bの重ね合わせ部分に対して両側から、即ち、図1に示すように上下方向から挟み込むように、銅合金からなる電極2A、2Bを押し付けつつ通電することにより、2枚の鋼板1A、1Bの間に溶融金属部を形成させる。この溶融金属部は、溶接通電が終了した後、水冷された電極2A、2Bによる抜熱や鋼板1A、1Bへの熱伝導によって急速に冷却されて凝固し、2枚の鋼板1A、1Bの間に、断面楕円形状のナゲット(溶接金属部)3が形成される。このようなナゲット3が形成されることにより、2枚の鋼板1A、1Bが溶接される。
あるいは、図2に示すように、3枚の鋼板1A、1B、1Cを重ね合わせ、上記同様に電極2A、2Bを押し付けつつ通電することにより、3枚の鋼板1A~1Cの間にナゲット(溶融金属部)3が形成されることで、3枚の鋼板1A~1Cが溶接される。3枚の鋼板1A、1B、1Cは、共に高強度鋼板であるか、2枚が高強度鋼板であって、外側の1枚(鋼板1A)が低強度鋼板(引張強さ780MPa未満)である。
なお、以下の説明では、便宜上、鋼板1A~1Cを単に鋼板1として記す場合もある。
本発明に係る高強度鋼板のスポット溶接方法の第1の実施形態について、以下に説明する。第1の実施形態の高強度鋼板のスポット溶接方法は、図1、図2に示すようなスポット溶接継手10を得るにあたり、2枚の鋼板1A、1B、あるいは3枚の鋼板1A~1Cを抵抗スポット溶接によって溶接する方法である。
具体的には、図1に示すように、2枚の鋼板1A、1Bをスポット溶接する場合、これら2枚の鋼板1A、1Bは、引張強さが共に780~1850MPaである。そして、板厚比={鋼板の板厚の総和}/{薄い側の鋼板の板厚(同厚の場合は1枚当たりの板厚)}が2以上、5以下の範囲にある。
図2に示すように、3枚の鋼板1A~1Cをスポット溶接する場合、これら3枚の鋼板1A~1Cは、引張強さが共に780~1850MPaである、又は、2枚の引張強さが共に780~1850MPaであり、その外側の1枚の引張強さが780MPa未満である。そして、板厚比={鋼板の板厚の総和}/{薄い側の鋼板の板厚(同厚の場合は1枚当たりの板厚)}が3以上、6以下の範囲にある。
第1の実施形態では、重ね合わされた鋼板1のスポット溶接前の隙間(以下、単に隙間と呼ぶ)がいずれも0.5(mm)未満である場合を想定する。
そして、加圧力P1、P2を、第1通電工程、第2通電工程を通して一定の加圧力P=P1=P2とするとともに、複数の鋼板1の平均板厚をt(mm)とするとき、下記(1)式で表される範囲とする。
0.5≦P≦3.0t(1/3) ・・・(1)
また、溶接電流I1を、溶接電流I2の30%以上、90%以下(以下、30~90%と記す)の範囲とする。
さらに、第1通電工程が終了した後、0.1(s)以内に第2通電工程を開始する。
以下に、被溶接物である鋼板1(図1に示す高強度鋼板1A、1B、又は図2に示す鋼板1A~1C)の特性の限定理由について詳述する。
被溶接物である鋼板1には、1枚あたりの引張強さが780~1850MPaの高強度鋼板が2枚以上含まれる。
鋼板の強度は、溶接部における応力集中状態にも大きな影響を及ぼすことから、破断形態劣化やそれに伴う強度ばらつき、強度低下にも影響を及ぼす。鋼板の引張強さが780MPa未満では、これらの問題は起こり難く、また、1850MPaを超えると、継手強度の低下やばらつきを防止するための改善が困難となる。
そこで、まず、鋼板特性を以下に説明する条件に規定した上で、詳細を後述する各溶接条件でスポット溶接を行う。これにより、高強度鋼板をスポット溶接した場合でも、スポット溶接継手の破断形態が良好で、また、インデンテーションの発生を抑制しながら強度のばらつきや低下を防止でき、信頼性の高い溶接部を形成させることが可能となる。
被溶接物である鋼板1の鋼種については特に限定されず、例えば、2相組織型(例えば、フェライト中にマルテンサイトを含む組織、フェライト中にベイナイトを含む組織等)、加工誘起変態型(フェライト中に残留オーステナイトを含む組織)、焼入れ型(マルテンサイト組織)、微細結晶型(フェライト主体組織)等、何れの型の鋼板であっても良い。何れの鋼種からなる高強度鋼板であっても、本発明を適用することにより、鋼板の特性を損なうことなく、スポット溶接の際に、インデンテーションの発生を抑制しつつ、且つ、散りの発生を抑制しながら、高強度鋼板を溶接することができる。これにより、破断形態が良好で強度のばらつきや低下が少なく、信頼性の高いスポット溶接継手(溶接部)が得られる。
被溶接物である鋼板1の表層に施されるめっき層の種類については、例えば、Zn系、Zn-Fe系、Zn-Ni系、Zn-Al系、Zn-Mg系、Pb-Sn系、Sn-Zn系、Al-Si系等、何れのめっき層であっても良い。また、めっき層の表層に無機系、有機系の皮膜(例えば、潤滑皮膜等)が施されていても良い。また、これらのめっき層の目付量についても、特に限定されないが、両面の目付け量で100(g/m2)/100g/m2)以下とすることが好ましい。めっきの目付け量が片面あたりで100(g/m2)を越えると、めっき層が溶接の際の障害となる場合がある。
被溶接物である鋼板1の板厚については、特に限定されず、自動車車体等の分野で用いられる一般的な板厚、例えば、0.6~3.2(mm)程度の板厚の鋼板であれば、本発明を適用することで上記効果が安定して得られる。しかしながら、板厚の増加とともに溶接部での応力集中も増加するので、鋼板1の板厚は、0.6~2.0(mm)の範囲であることがより好ましい。
以下に、抵抗スポット溶接の際の溶接条件について、その限定理由を詳述する。
第1通電工程において前通電を行った後、0.1(s)以内に第2通電工程による本通電を行う。即ち、第1通電工程の後、直ちに第2通電工程を行うか、あるいは、0.1(s)以内の通電休止時間の後に第2通電工程を行うパターンとしている。その際に、第1通電工程の溶接電流I1を、第2通電工程の溶接電流I2よりも低い電流としている。ここで、電流とは、交流電源の場合には、その実効値を表すものとする。
また、電極2A、2Bによる加圧力Pは、第1通電工程及び第2通電工程を通して一定とされており、さらに、第1通電工程と第2通電工程との間の通電休止時間においても加圧状態とされている。
第1通電工程及び第2通電工程を行う際の、溶接通電を行う際の、電極2A、2Bの鋼板1に対する加圧力P(kN)を、下記(1)式で表される範囲に規定する。
0.5≦P≦3.0t(1/3) ・・・(1)
但し、上記(1)式において、P:電極2A、2Bによる加圧力(kN)、t:鋼板1の平均板厚(mm)を示す。
前通電である第1通電工程における溶接電流I1(kA)を、本通電である第2通電工程における溶接電流I2(kA)の30~90%の範囲に規定している。
前通電である第1通電工程が終了した後、0.1(s)以内に本通電である第2通電工程を開始する。即ち、第1通電工程の後、直ちに第2通電工程を行うか、あるいは、0.1(s)以内の通電休止時間の後に第2通電工程を行うパターンとすることができる。
溶接電流や通電時間等の具体的な数値に関しては特に限定されず、鋼板を溶接する抵抗スポット溶接方法において、従来から採用されている電流値及び通電時間と同程度とすれば良い。
本発明に係る高強度鋼板のスポット溶接方法の第2の実施形態について、以下に説明する。なお、第2の実施形態では、上記第1の実施形態と同じ図面を参照してその構成を説明するとともに、共通する構成については同じ符号を付し、その詳しい説明を省略する。
第2の実施形態では、スポット溶接は、加圧力P1(kN)、溶接電流I1(kA)の前通電である第1通電工程と、加圧力P2(kN)、溶接電流I2(kA)の本通電である第2通電工程とからなる。
そして、加圧力P1、P2を、複数の鋼板1の平均板厚をt(mm)とするとき、下記(2)式、(3)式で表される範囲とする。
0.5≦P2≦3.0t(1/3) ・・・(2)
1.0×P2<P1≦2.0×P2 ・・・(3)
また、溶接電流I1を、溶接電流I2の30~90%の範囲とする。
さらに、第1通電工程が終了した後、0.1(s)以内に第2通電工程を開始する。
本発明に係る高強度鋼板のスポット溶接方法の第3の実施形態について、以下に説明する。なお、第3の実施形態では、上記第1、2の実施形態と同じ図面を参照してその構成を説明するとともに、共通する構成については同じ符号を付し、その詳しい説明を省略する。
具体的には、上記第1の実施形態又は第2の実施形態で説明した方法において、本通電である第2通電工程の後に、後通電である第3通電工程を設けている。そして、この第3通電工程においては、溶接電流をI3(kA)とし、通電時間をT3(s)とし、第2通電工程と第3通電工程との間の無通電時間をTC(s)で表したとき、溶接電流I3を3(kA)以上、15(kA)以下(以下、3~15(kA)と記す)の範囲とする。
また、無通電時間TCを0(s)以上、0.2(s)以内(以下、0~0.2(s)と記す)の範囲とする。
さらに、溶接電流I3と前記通電時間T3との関係を下記(4)式で表される範囲とする。
I3×T3≦0.7+TC ・・・(4)
電極2A、2Bの加圧力については、上記第1の実施形態におけるパターン(加圧力P)、あるいは、第2の実施形態におけるパターン(加圧力P1、P2)と同様とすることができる。また、これらの加圧力のパターンを採用するにあたり、第3通電工程における加圧力については、その前の第2通電工程における加圧力、即ち、第1の実施形態における加圧力Pか、あるいは、第2の実施形態における加圧力P2と同じ加圧力とすることができる。
第1通電工程(前通電)、第2通電工程(本通電)に加え、上記条件の第3通電工程(後通電)を有することで、多段通電による継手強度向上の効果が顕著に得られる。このような後通電の条件は、溶接金属部や熱影響部の組織、偏析状態に大きな影響を及ぼす。第3の実施形態では、後通電である第3通電工程の各条件を、以下に詳述するような条件に既定する。
第3通電工程では、まず、溶接電流I3を3~15(kA)の範囲の範囲に規定する。この溶接電流I3は、溶接金属部や熱影響部の組織、偏析状態に対して、特に大きな影響を及ぼす。第3通電工程における溶接電流I3をこの範囲とすることで、多段通電による継手強度向上の効果がより顕著に得られる。
第3通電工程における溶接電流I3が3(kA)未満だと、後通電による継手強度向上の効果が得られ難く、また、15(kA)を超えると、散りが発生し易くなって上記効果が低減してしまう。
第3通電工程では、第2通電工程と第3通電工程の間の無通電時間TCを、0~0.2(s)の範囲、即ち、第2通電工程が終了した後、直ちに第3通電工程を開始するか、あるいは、第2通電工程の終了後、0.2(s)以内に第3通電工程を開始する条件で既定する。
第3通電工程では、溶接電流I3と通電時間T3との関係を、次式{I3×T3≦0.7+TC}で表される関係を満たす範囲、即ち、溶接電流I3と通電時間T3とを乗じて得られる値の範囲を、上記無通電時間TCを基に規定している。
従って、例えば、自動車用部品の製造や車体の組立等の工程においては、車体全体の軽量化による低燃費化や炭酸ガス(CO2)の排出量削減等のメリットを十分に享受することができ、その社会的貢献は計り知れない。
実施例1は、第1の実施形態を実証するためのものである。
図7に示すような板厚、鋼種の鋼板を用い、40×40(mm)の組織観察用試験片を作製した。図7に示す鋼種のうち、CR1470HPやCR1780HPは、特開2000-234153号公報等に開示されているホットプレス(ホットスタンピング)鋼板を示す。GA1180Yは、日本鉄鋼連盟規格品(JAC1180Y)を示す。CR980Yは、日本鉄鋼連盟規格品のJSC980Yを、CR270DはJSC270Dをそれぞれ示す。なお、CRは冷延鋼板を、GAは合金化亜鉛めっき鋼板を意味する。
そして、光学顕微鏡を用いて断面のマクロ組織観察を行い、ナゲット径を測定した。
また、高強度鋼板の表面に発生したインデンテーションについて、その深さを溶接部断面にて測定した。
そして、剥離方向、即ち、図6A、図6Bの符号6で示すように、上側の試験片を上方向に、下側の試験片を下方向に、相互に剥離する方向で荷重を付加することで十字引張試験を実施し、十字引張強さ(CTS)を測定した。ここで、一般に、高強度鋼板を重ね合わせてスポット溶接した場合、最も薄い鋼板の板厚tが0.7(mm)の場合には、十字引張強さが2.5(kN)以上であれば、十分なCTSを有していると言うことができる。同様に、最も薄い鋼板の板厚tが1.0(mm)、1.6(mm)、2.0(mm)の場合には、それぞれ十字引張強さが5(kN)、9(kN)、11(kN)以上であれば、十分なCTSを有していると言うことができる。
また、上記の手順で、第1の実施形態で説明した範囲外の溶接条件で抵抗スポット溶接を行い、上記の方法で各種試験を行った(図7の比較例を参照)。
図7に、各試験片の作製条件並びに試験結果の一覧を示す。実施例1は、第1の実施形態を実証するためのものであり、各条件番号において加圧力P1、P2を同じ数値(加圧力P)としている。
また、条件番号15は、板厚0.7(mm)のCR980Yと、板厚4.0(mm)のCR980Yとを2枚重ね合わせてスポット溶接した例であるが、板厚に差があり過ぎて、接合自体が不可であった。
なお、条件番号16~18では、ナゲット径は高強度鋼板であるCR980Yの板界面でのナゲット径を測定した。また、十字引張強さ(CTS)もCR980Y同士を引き離すように引張った値、即ち、CR980Y間の溶接部の強度を測定した。
実施例2は、第2の実施形態を実証するためのものである。
図8に示すような板厚、鋼種の鋼板を用い、実施例1と同様の手順で組織観察用試験片及び十字引張試験片を作製し、同様の方法で各種試験を行った。なお、鋼板1間の重ね隙間は、所定の隙間に相当する板厚のスペーサー用鋼板を溶接評価される鋼板1の間に挟み込むことで設定した。具体的には、図11A、図11Bに示すように、スペーサー用鋼板11を、その間隔を40mmとして評価される溶接部の両外側に配して、鋼板1間に所定の隙間を確保した。
図8に、各試験片の作製条件並びに試験結果の一覧を示す。実施例2は、第2の実施形態を実証するためのものであり、第1通電工程(前通電)における加圧力P1と、第2通電工程(本通電)における加圧力P2とを異なる数値としている。
なお、条件番号36~38では、ナゲット径は高強度鋼板であるCR980Yの板界面でのナゲット径を測定した。また、十字引張強さ(CTS)もCR980Y同士を引き離すように引張った値、即ち、CR980Y間の溶接部の強度を測定した。
実施例3は、第3の実施形態のうち、第1の実施形態における第2通電工程の後に、後通電である第3通電工程を有するようにした場合を実証するためのものである。
図9に示すような板厚、鋼種の鋼板を用い、実施例1と同様の手順で組織観察用試験片及び十字引張試験片を作製し、同様の方法で各種試験を行った。
図9に、各試験片の作製条件並びに試験結果の一覧を示す。実施例3は、第3の実施形態を実証するためのものであり、第1通電工程、第2通電工程では第1の実施形態で説明した範囲内のスポット溶接条件を満たすものとしている。
また、条件番号41、42、45と、条件番号2とは第3通電工程の有無以外は同じ条件であるが、条件番号41、42、45では、条件番号2に比べて十字引張試験による十字引張強さ(CTS)が高くなることが明らかとなった。
実施例4は、第3の実施形態のうち、第2の実施形態における第2通電工程の後に、後通電である第3通電工程を有するようにした場合を実証するためのものである。
図10に示すような板厚、鋼種の鋼板を用い、実施例1と同様の手順で組織観察用試験片及び十字引張試験片を作製し、同様の方法で各種試験を行った。
図10に、各試験片の作製条件並びに試験結果の一覧を示す。実施例4は、第3の実施形態を実証するためのものであり、第1通電工程、第2通電工程では第2の実施形態で説明した範囲内のスポット溶接条件を満たすものとしている。
また、条件番号51、52、55と、条件番号22とは第3通電工程の有無以外は同じ条件であるが、条件番号51、52、55では、条件番号22に比べて十字引張試験による十字引張強さ(CTS)が高くなることが明らかとなった。
同様に、条件番号56、57と、条件番号25とは第3通電工程の有無以外は同じ条件であるが、条件番号56、57では、条件番号25に比べて十字引張試験による十字引張強さ(CTS)が高くなることが明らかとなった。
Claims (6)
- 複数の鋼板を重ね合わせて抵抗スポット溶接する、継手強度に優れた高強度鋼板のスポット溶接方法であって、
前記複数の鋼板は、
引張強さが共に780MPa以上、1850MPa以下である2枚の鋼板であって、板厚比={鋼板の板厚の総和}/{薄い側の鋼板の板厚(同厚の場合は1枚当たりの板厚)}が2以上、5以下の範囲となる2枚の鋼板である、
あるいは、引張強さが共に780MPa以上、1850MPa以下である3枚の鋼板、又は、引張強さが共に780MPa以上、1850MPa以下である2枚の鋼板とその外側の引張強さが780MPa未満である1枚の鋼板であって、板厚比={鋼板の板厚の総和}/{薄い側の鋼板の板厚(同厚の場合は1枚当たりの板厚)}が3以上、6以下の範囲となる3枚の鋼板であり、
前記スポット溶接は、加圧力P1(kN)、溶接電流I1(kA)の前通電である第1通電工程と、加圧力P2(kN)、溶接電流I2(kA)の本通電である第2通電工程とからなり、
前記加圧力P1、P2を、前記第1通電工程、前記第2通電工程を通して一定の加圧力P=P1=P2とするとともに、前記複数の鋼板の平均板厚をt(mm)とするとき、下記(1)式で表される範囲とし、
0.5≦P≦3.0t(1/3) ・・・(1)
前記溶接電流I1を、前記溶接電流I2の30%以上、90%以下の範囲とし、
前記第1通電工程が終了した後、0.1(s)以内に前記第2通電工程を開始することを特徴とする継手強度に優れた高強度鋼板のスポット溶接方法。 - 複数の鋼板を重ね合わせて抵抗スポット溶接する、継手強度に優れた高強度鋼板のスポット溶接方法であって、
前記複数の鋼板は、
引張強さが共に780MPa以上、1850MPa以下である2枚の鋼板であって、板厚比={鋼板の板厚の総和}/{薄い側の鋼板の板厚(同厚の場合は1枚当たりの板厚)}が2以上、5以下の範囲となる2枚の鋼板である、
あるいは、引張強さが共に780MPa以上、1850MPa以下である3枚の鋼板、又は、引張強さが共に780MPa以上、1850MPa以下である2枚の鋼板とその外側の引張強さが780MPa未満である1枚の鋼板であって、板厚比={鋼板の板厚の総和}/{薄い側の鋼板の板厚(同厚の場合は1枚当たりの板厚)}が3以上、6以下の範囲となる3枚の鋼板であり、
前記スポット溶接は、加圧力P1(kN)、溶接電流I1(kA)の前通電である第1通電工程と、加圧力P2(kN)、溶接電流I2(kA)の本通電である第2通電工程とからなり、
前記加圧力P1、P2を、前記複数の鋼板の平均板厚をt(mm)とするとき、下記(2)式、(3)式で表される範囲とし、
0.5≦P2≦3.0t(1/3) ・・・(2)
1.0×P2<P1≦2.0×P2 ・・・(3)
前記溶接電流I1を、前記溶接電流I2の30%以上、90%以下の範囲とし、
前記第1通電工程が終了した後、0.1(s)以内に前記第2通電工程を開始することを特徴とする継手強度に優れた高強度鋼板のスポット溶接方法。 - 前記重ね合わされた鋼板のスポット溶接前の隙間がいずれも0.5(mm)未満であることを特徴とする請求項1に記載の継手強度に優れた高強度鋼板のスポット溶接方法。
- 前記重ね合わされた鋼板のスポット溶接前の隙間のうち少なくとも1箇所が0.5(mm)以上であることを特徴とする請求項2に記載の継手強度に優れた高強度鋼板のスポット溶接方法。
- 本通電である前記第2通電工程の後に、後通電である第3通電工程を有し、
前記第3通電工程の溶接電流をI3(kA)とし、通電時間をT3(s)とし、前記第2通電工程と該第3通電工程との間の無通電時間をTC(s)で表したとき、
前記溶接電流I3を3(kA)以上、15(kA)以下の範囲とし、
前記無通電時間TCを0(s)以上、0.2(s)以内の範囲として、
前記溶接電流I3と前記通電時間T3との関係を下記(4)式で表される範囲とする
I3×T3≦0.7+TC ・・・(4)
ことを特徴とする請求項1に記載の継手強度に優れた高強度鋼板のスポット溶接方法。 - 本通電である前記第2通電工程の後に、後通電である第3通電工程を有し、
前記第3通電工程の溶接電流をI3(kA)とし、通電時間をT3(s)とし、前記第2通電工程と該第3通電工程との間の無通電時間をTC(s)で表したとき、
前記溶接電流I3を3(kA)以上、15(kA)以下の範囲とし、
前記無通電時間TCを0(s)以上、0.2(s)以内の範囲として、
前記溶接電流I3と前記通電時間T3との関係を下記(4)式で表される範囲とする
I3×T3≦0.7+TC ・・・(4)
ことを特徴とする請求項2に記載の継手強度に優れた高強度鋼板のスポット溶接方法。
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020157002933A KR101744427B1 (ko) | 2012-09-24 | 2012-09-24 | 조인트 강도가 우수한 고강도 강판의 스폿 용접 방법 |
US14/417,075 US10040145B2 (en) | 2012-09-24 | 2012-09-24 | Spot welding method of high-strength steel sheets excellent in joint strength |
CN201280075980.0A CN104661784B (zh) | 2012-09-24 | 2012-09-24 | 接头强度优异的高强度钢板的点焊方法 |
MX2015001909A MX364023B (es) | 2012-09-24 | 2012-09-24 | Metodo de soldadura por puntos para lamina de acero de alta resistencia excelente en resistencia de union. |
IN600DEN2015 IN2015DN00600A (ja) | 2012-09-24 | 2012-09-24 | |
JP2013513324A JP5418726B1 (ja) | 2012-09-24 | 2012-09-24 | 継手強度に優れた高強度鋼板のスポット溶接方法 |
PCT/JP2012/074355 WO2014045431A1 (ja) | 2012-09-24 | 2012-09-24 | 継手強度に優れた高強度鋼板のスポット溶接方法 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2012/074355 WO2014045431A1 (ja) | 2012-09-24 | 2012-09-24 | 継手強度に優れた高強度鋼板のスポット溶接方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014045431A1 true WO2014045431A1 (ja) | 2014-03-27 |
Family
ID=50287178
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/074355 WO2014045431A1 (ja) | 2012-09-24 | 2012-09-24 | 継手強度に優れた高強度鋼板のスポット溶接方法 |
Country Status (7)
Country | Link |
---|---|
US (1) | US10040145B2 (ja) |
JP (1) | JP5418726B1 (ja) |
KR (1) | KR101744427B1 (ja) |
CN (1) | CN104661784B (ja) |
IN (1) | IN2015DN00600A (ja) |
MX (1) | MX364023B (ja) |
WO (1) | WO2014045431A1 (ja) |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2014184472A (ja) * | 2013-03-25 | 2014-10-02 | Nisshin Steel Co Ltd | 抵抗熱により接合されたステンレス鋼板製成型品 |
WO2016088319A1 (ja) * | 2014-12-01 | 2016-06-09 | Jfeスチール株式会社 | 抵抗スポット溶接方法 |
CN107405717A (zh) * | 2015-03-16 | 2017-11-28 | 杰富意钢铁株式会社 | 电阻点焊方法和电阻点焊接头的制造方法 |
JP2018030178A (ja) * | 2014-05-07 | 2018-03-01 | 新日鐵住金株式会社 | スポット溶接方法 |
JP2018079503A (ja) * | 2016-11-18 | 2018-05-24 | マツダ株式会社 | スポット溶接物の製造方法およびスポット溶接電極 |
JP2019136748A (ja) * | 2018-02-13 | 2019-08-22 | トヨタ自動車株式会社 | 抵抗スポット溶接方法 |
JP2020049541A (ja) * | 2018-09-28 | 2020-04-02 | 日本製鉄株式会社 | スポット溶接継手の製造方法 |
JP2020514071A (ja) * | 2017-03-07 | 2020-05-21 | アルセロールミタル | 亜鉛被覆鋼板を接合するための抵抗スポット溶接方法 |
WO2020105267A1 (ja) * | 2018-11-19 | 2020-05-28 | 株式会社神戸製鋼所 | 接合構造体及び接合構造体の製造方法 |
WO2020105266A1 (ja) * | 2018-11-19 | 2020-05-28 | 株式会社神戸製鋼所 | 接合構造体及び接合構造体の製造方法 |
KR20200086730A (ko) | 2017-12-19 | 2020-07-17 | 닛폰세이테츠 가부시키가이샤 | 저항 스폿 용접 조인트의 제조 방법 |
JPWO2019180923A1 (ja) * | 2018-03-23 | 2020-12-03 | 本田技研工業株式会社 | スポット溶接方法 |
WO2021070836A1 (ja) | 2019-10-09 | 2021-04-15 | Jfeスチール株式会社 | 抵抗スポット溶接方法および溶接部材の製造方法 |
JP2021079416A (ja) * | 2019-11-20 | 2021-05-27 | トヨタ自動車株式会社 | 抵抗スポット溶接方法 |
JP2021159919A (ja) * | 2020-03-30 | 2021-10-11 | フタバ産業株式会社 | 接合部材の製造方法 |
JP7355281B1 (ja) | 2022-06-03 | 2023-10-03 | Jfeスチール株式会社 | 溶接継手、溶接部材およびその製造方法、ならびに、抵抗スポット溶接方法 |
WO2023233704A1 (ja) * | 2022-06-03 | 2023-12-07 | Jfeスチール株式会社 | 溶接継手、溶接部材およびその製造方法、ならびに、抵抗スポット溶接方法 |
Families Citing this family (31)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5333560B2 (ja) * | 2011-10-18 | 2013-11-06 | Jfeスチール株式会社 | 高張力鋼板の抵抗スポット溶接方法及び抵抗スポット溶接継手 |
US20160082543A1 (en) * | 2013-06-05 | 2016-03-24 | Nippon Steel & Sumitomo Metal Corporation | Spot-welded joint and spot welding method |
JP6481270B2 (ja) * | 2014-07-03 | 2019-03-13 | 新日鐵住金株式会社 | 高強度低比重鋼板の抵抗スポット溶接方法及び溶接継手 |
JP6409470B2 (ja) * | 2014-09-30 | 2018-10-24 | 新日鐵住金株式会社 | スポット溶接方法 |
CN107848061B (zh) * | 2015-07-10 | 2021-03-09 | 杰富意钢铁株式会社 | 电阻点焊方法 |
JP6052480B1 (ja) * | 2015-07-10 | 2016-12-27 | Jfeスチール株式会社 | 抵抗スポット溶接方法 |
WO2017038981A1 (ja) * | 2015-09-03 | 2017-03-09 | 新日鐵住金株式会社 | スポット溶接方法 |
JP6108018B2 (ja) * | 2015-09-03 | 2017-04-05 | 新日鐵住金株式会社 | スポット溶接方法 |
JP6108017B2 (ja) * | 2015-09-03 | 2017-04-05 | 新日鐵住金株式会社 | スポット溶接方法 |
US10272515B2 (en) * | 2015-09-15 | 2019-04-30 | GM Global Technology Operations LLC | Power pulse method for controlling resistance weld nugget growth and properties during steel spot welding |
CA3001971A1 (en) * | 2015-10-21 | 2017-04-27 | Nippon Steel & Sumitomo Metal Corporation | Method of resistance spot welding a plurality of steel sheets |
CN105478982A (zh) * | 2015-12-03 | 2016-04-13 | 天津大学 | 一种铝合金-高强钢的电阻塞焊方法 |
EP3427891B1 (en) | 2016-03-08 | 2021-05-05 | Nippon Steel Corporation | Flux-cored wire, weld joint manufacturing method and weld joint |
US11065712B2 (en) * | 2016-06-09 | 2021-07-20 | Jfe Steel Corporation | Resistance spot welding method |
CN106994551A (zh) * | 2017-05-17 | 2017-08-01 | 中南大学 | 一种能有效提高先进高强钢钢板焊点强度的电阻点焊工艺 |
WO2019002924A1 (fr) * | 2017-06-30 | 2019-01-03 | Aperam | Procédé de soudage par points de tôles d'acier inoxydable martensitique |
KR102010073B1 (ko) | 2017-12-22 | 2019-08-12 | 주식회사 포스코 | 스폿 용접 방법 |
CN108127215A (zh) * | 2017-12-26 | 2018-06-08 | 重庆平伟汽车科技股份有限公司 | 一种减少点焊飞溅的方法 |
WO2019160141A1 (ja) * | 2018-02-19 | 2019-08-22 | Jfeスチール株式会社 | 抵抗スポット溶接方法および溶接部材の製造方法 |
JP7026532B2 (ja) * | 2018-02-28 | 2022-02-28 | ダイハツ工業株式会社 | スポット溶接方法 |
US20200016679A1 (en) * | 2018-07-13 | 2020-01-16 | GM Global Technology Operations LLC | Pretreatment of weld flanges to mitigate liquid metal embrittlement cracking in resistance welding of galvanized steels |
JP2020019027A (ja) * | 2018-07-30 | 2020-02-06 | ダイハツ工業株式会社 | インダイレクトスポット溶接用の溶接電極の先端形状の評価方法 |
JP7094374B2 (ja) * | 2018-09-05 | 2022-07-01 | 本田技研工業株式会社 | スポット溶接方法 |
US20200114459A1 (en) * | 2018-10-15 | 2020-04-16 | GM Global Technology Operations LLC | Quality welding of similar and dissimilar metal welds with space between workpieces |
CN112955271B (zh) * | 2018-11-26 | 2022-10-04 | 本田技研工业株式会社 | 点焊方法 |
JP7112602B2 (ja) * | 2019-08-20 | 2022-08-03 | 本田技研工業株式会社 | スポット溶接方法 |
US11383319B2 (en) | 2019-09-05 | 2022-07-12 | GM Global Technology Operations LLC | Method of joining steel having different resistivities |
US11590601B2 (en) | 2019-09-20 | 2023-02-28 | GM Global Technology Operations LLC | Method of joining steel work-pieces having different gauge ratios |
EP4043140A4 (en) * | 2019-10-09 | 2022-12-21 | JFE Steel Corporation | METHOD OF RESISTANCE SPOT WELDING AND METHOD OF MANUFACTURING A WELDED PART |
JP7335196B2 (ja) * | 2020-04-15 | 2023-08-29 | 株式会社神戸製鋼所 | 抵抗溶接部材の製造方法 |
JP7208193B2 (ja) * | 2020-07-08 | 2023-01-18 | フタバ産業株式会社 | 抵抗スポット溶接方法及び抵抗スポット溶接装置 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1058157A (ja) * | 1996-06-13 | 1998-03-03 | Kawasaki Heavy Ind Ltd | スポット溶接の制御方法および装置 |
JP2006043731A (ja) * | 2004-08-04 | 2006-02-16 | Daihatsu Motor Co Ltd | スポット溶接の通電制御方法 |
JP2006095572A (ja) * | 2004-09-30 | 2006-04-13 | Daihen Corp | 抵抗溶接制御方法 |
JP2010115706A (ja) * | 2008-10-16 | 2010-05-27 | Jfe Steel Corp | 高強度鋼板の抵抗スポット溶接方法 |
JP2011152574A (ja) * | 2010-01-28 | 2011-08-11 | Honda Motor Co Ltd | 抵抗溶接方法 |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3114440B2 (ja) * | 1993-07-22 | 2000-12-04 | 日産自動車株式会社 | スポット溶接装置 |
DE19917896B4 (de) * | 1998-04-20 | 2019-02-21 | Nissan Motor Co., Ltd. | Punktschweißverfahren |
JP2009190046A (ja) | 2008-02-12 | 2009-08-27 | Kobe Steel Ltd | 高張力鋼板のスポット溶接方法と高張力鋼板の溶接継手 |
JP5151615B2 (ja) | 2008-03-28 | 2013-02-27 | 新日鐵住金株式会社 | 高強度鋼板のスポット溶接方法 |
JP5599553B2 (ja) | 2008-03-31 | 2014-10-01 | Jfeスチール株式会社 | 抵抗スポット溶接方法 |
CN100562396C (zh) * | 2008-07-11 | 2009-11-25 | 广州(从化)亨龙机电制造实业有限公司 | 一种电阻焊方法 |
JP5573128B2 (ja) | 2008-11-28 | 2014-08-20 | Jfeスチール株式会社 | 抵抗スポット溶接方法 |
JP5415896B2 (ja) * | 2009-01-29 | 2014-02-12 | Jfeスチール株式会社 | インダイレクトスポット溶接方法 |
JP5293227B2 (ja) | 2009-01-30 | 2013-09-18 | Jfeスチール株式会社 | 高強度薄鋼板の抵抗スポット溶接方法 |
JP5359571B2 (ja) | 2009-02-12 | 2013-12-04 | 新日鐵住金株式会社 | 高張力鋼板の抵抗溶接方法および抵抗溶接継手の製造方法 |
JP5640409B2 (ja) | 2009-03-17 | 2014-12-17 | Jfeスチール株式会社 | 抵抗スポット溶接継手の製造方法 |
JP5640410B2 (ja) | 2009-03-17 | 2014-12-17 | Jfeスチール株式会社 | 抵抗スポット溶接継手の製造方法 |
JP5427074B2 (ja) * | 2009-03-31 | 2014-02-26 | 本田技研工業株式会社 | 抵抗溶接方法及びその装置 |
JP5332857B2 (ja) | 2009-04-20 | 2013-11-06 | 新日鐵住金株式会社 | 高張力鋼板の抵抗溶接方法 |
CN101961814A (zh) * | 2009-07-24 | 2011-02-02 | 宝山钢铁股份有限公司 | 一种热镀铝锌钢板的点焊方法 |
JP2011067853A (ja) * | 2009-09-28 | 2011-04-07 | Nippon Steel Corp | 高強度鋼板のスポット溶接方法 |
-
2012
- 2012-09-24 IN IN600DEN2015 patent/IN2015DN00600A/en unknown
- 2012-09-24 CN CN201280075980.0A patent/CN104661784B/zh active Active
- 2012-09-24 MX MX2015001909A patent/MX364023B/es active IP Right Grant
- 2012-09-24 KR KR1020157002933A patent/KR101744427B1/ko active IP Right Grant
- 2012-09-24 WO PCT/JP2012/074355 patent/WO2014045431A1/ja active Application Filing
- 2012-09-24 US US14/417,075 patent/US10040145B2/en active Active
- 2012-09-24 JP JP2013513324A patent/JP5418726B1/ja active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1058157A (ja) * | 1996-06-13 | 1998-03-03 | Kawasaki Heavy Ind Ltd | スポット溶接の制御方法および装置 |
JP2006043731A (ja) * | 2004-08-04 | 2006-02-16 | Daihatsu Motor Co Ltd | スポット溶接の通電制御方法 |
JP2006095572A (ja) * | 2004-09-30 | 2006-04-13 | Daihen Corp | 抵抗溶接制御方法 |
JP2010115706A (ja) * | 2008-10-16 | 2010-05-27 | Jfe Steel Corp | 高強度鋼板の抵抗スポット溶接方法 |
JP2011152574A (ja) * | 2010-01-28 | 2011-08-11 | Honda Motor Co Ltd | 抵抗溶接方法 |
Cited By (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2014184472A (ja) * | 2013-03-25 | 2014-10-02 | Nisshin Steel Co Ltd | 抵抗熱により接合されたステンレス鋼板製成型品 |
JP2018030178A (ja) * | 2014-05-07 | 2018-03-01 | 新日鐵住金株式会社 | スポット溶接方法 |
EP3228414A4 (en) * | 2014-12-01 | 2017-12-13 | JFE Steel Corporation | Resistance spot welding method |
CN107000109A (zh) * | 2014-12-01 | 2017-08-01 | 杰富意钢铁株式会社 | 电阻点焊方法 |
US20170312846A1 (en) * | 2014-12-01 | 2017-11-02 | Jfe Steel Corporation | Resistance spot welding method |
JPWO2016088319A1 (ja) * | 2014-12-01 | 2017-04-27 | Jfeスチール株式会社 | 抵抗スポット溶接方法 |
KR101906084B1 (ko) * | 2014-12-01 | 2018-10-08 | 제이에프이 스틸 가부시키가이샤 | 저항 스폿 용접 방법 |
WO2016088319A1 (ja) * | 2014-12-01 | 2016-06-09 | Jfeスチール株式会社 | 抵抗スポット溶接方法 |
US10625365B2 (en) | 2014-12-01 | 2020-04-21 | Jfe Steel Corporation | Resistance spot welding method |
CN107405717A (zh) * | 2015-03-16 | 2017-11-28 | 杰富意钢铁株式会社 | 电阻点焊方法和电阻点焊接头的制造方法 |
US10625368B2 (en) | 2015-03-16 | 2020-04-21 | Jfe Steel Corporation | Resistance spot welding method and method for manufacturing resistance spot welded joint |
EP3272451A4 (en) * | 2015-03-16 | 2018-05-02 | JFE Steel Corporation | Resistance spot welding method and method for manufacturing resistance spot welded joint |
CN107405717B (zh) * | 2015-03-16 | 2019-11-05 | 杰富意钢铁株式会社 | 电阻点焊方法和电阻点焊接头的制造方法 |
JP2018079503A (ja) * | 2016-11-18 | 2018-05-24 | マツダ株式会社 | スポット溶接物の製造方法およびスポット溶接電極 |
JP2020514071A (ja) * | 2017-03-07 | 2020-05-21 | アルセロールミタル | 亜鉛被覆鋼板を接合するための抵抗スポット溶接方法 |
KR20200086730A (ko) | 2017-12-19 | 2020-07-17 | 닛폰세이테츠 가부시키가이샤 | 저항 스폿 용접 조인트의 제조 방법 |
US11135671B2 (en) | 2018-02-13 | 2021-10-05 | Toyota Jidosha Kabushiki Kaisha | Resistance spot welding method |
JP2019136748A (ja) * | 2018-02-13 | 2019-08-22 | トヨタ自動車株式会社 | 抵抗スポット溶接方法 |
JP7010720B2 (ja) | 2018-02-13 | 2022-01-26 | トヨタ自動車株式会社 | 抵抗スポット溶接方法 |
JP7038193B2 (ja) | 2018-03-23 | 2022-03-17 | 本田技研工業株式会社 | スポット溶接方法 |
JPWO2019180923A1 (ja) * | 2018-03-23 | 2020-12-03 | 本田技研工業株式会社 | スポット溶接方法 |
JP7139847B2 (ja) | 2018-09-28 | 2022-09-21 | 日本製鉄株式会社 | スポット溶接継手の製造方法 |
JP2020049541A (ja) * | 2018-09-28 | 2020-04-02 | 日本製鉄株式会社 | スポット溶接継手の製造方法 |
JP2020082104A (ja) * | 2018-11-19 | 2020-06-04 | 株式会社神戸製鋼所 | 接合構造体及び接合構造体の製造方法 |
WO2020105266A1 (ja) * | 2018-11-19 | 2020-05-28 | 株式会社神戸製鋼所 | 接合構造体及び接合構造体の製造方法 |
WO2020105267A1 (ja) * | 2018-11-19 | 2020-05-28 | 株式会社神戸製鋼所 | 接合構造体及び接合構造体の製造方法 |
WO2021070836A1 (ja) | 2019-10-09 | 2021-04-15 | Jfeスチール株式会社 | 抵抗スポット溶接方法および溶接部材の製造方法 |
JP2021079416A (ja) * | 2019-11-20 | 2021-05-27 | トヨタ自動車株式会社 | 抵抗スポット溶接方法 |
JP7201570B2 (ja) | 2019-11-20 | 2023-01-10 | トヨタ自動車株式会社 | 抵抗スポット溶接方法 |
JP2021159919A (ja) * | 2020-03-30 | 2021-10-11 | フタバ産業株式会社 | 接合部材の製造方法 |
JP7152439B2 (ja) | 2020-03-30 | 2022-10-12 | フタバ産業株式会社 | 接合部材の製造方法 |
US11590600B2 (en) | 2020-03-30 | 2023-02-28 | Futaba Industrial Co., Ltd. | Manufacturing method of joined member |
JP7355281B1 (ja) | 2022-06-03 | 2023-10-03 | Jfeスチール株式会社 | 溶接継手、溶接部材およびその製造方法、ならびに、抵抗スポット溶接方法 |
WO2023233704A1 (ja) * | 2022-06-03 | 2023-12-07 | Jfeスチール株式会社 | 溶接継手、溶接部材およびその製造方法、ならびに、抵抗スポット溶接方法 |
Also Published As
Publication number | Publication date |
---|---|
US20150174690A1 (en) | 2015-06-25 |
KR20150023936A (ko) | 2015-03-05 |
CN104661784A (zh) | 2015-05-27 |
MX2015001909A (es) | 2015-06-05 |
CN104661784B (zh) | 2017-11-07 |
JP5418726B1 (ja) | 2014-02-19 |
US10040145B2 (en) | 2018-08-07 |
JPWO2014045431A1 (ja) | 2016-08-18 |
KR101744427B1 (ko) | 2017-06-07 |
IN2015DN00600A (ja) | 2015-06-26 |
MX364023B (es) | 2019-04-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5418726B1 (ja) | 継手強度に優れた高強度鋼板のスポット溶接方法 | |
US11426820B2 (en) | Hot-formed previously welded steel part with very high mechanical resistance and production method | |
JP6194765B2 (ja) | 高強度鋼板のスポット溶接方法 | |
TWI587954B (zh) | Point welding joints and point welding method | |
KR101588257B1 (ko) | 고장력 강판의 저항 스폿 용접 방법 및 저항 스폿 용접 조인트 | |
TWI601588B (zh) | Resistance point welding method | |
JP5626025B2 (ja) | 溶接部の遅れ破壊特性並びに静的強度特性に優れた自動車用構造部材、および、その製造方法 | |
JP6409470B2 (ja) | スポット溶接方法 | |
JP5299257B2 (ja) | 高強度鋼板のスポット溶接方法 | |
JP5708350B2 (ja) | プロジェクション溶接継手およびその製造方法 | |
JP2011067853A (ja) | 高強度鋼板のスポット溶接方法 | |
KR20220127335A (ko) | 저항 스폿 용접 방법 및 저항 스폿 용접 이음매의 제조 방법 | |
JP2017047476A (ja) | スポット溶接方法 | |
JP6379819B2 (ja) | 重ね溶接部材、重ね溶接部材の重ね抵抗シーム溶接方法及び重ね溶接部を備える自動車用重ね溶接部材 | |
JP2017047475A (ja) | スポット溶接方法 | |
JP6168246B1 (ja) | 抵抗スポット溶接方法および溶接部材の製造方法 | |
JP6879345B2 (ja) | 抵抗スポット溶接方法、抵抗スポット溶接継手の製造方法 | |
JP6315161B1 (ja) | 抵抗スポット溶接方法 | |
JPWO2020036198A1 (ja) | 抵抗スポット溶接部材及びその製造方法 | |
JP2010240739A (ja) | 抵抗スポット溶接継手の製造方法 | |
TWI498178B (zh) | Fitting method of high strength steel plate with excellent joint strength | |
JP7435935B1 (ja) | 溶接部材およびその製造方法 | |
WO2024063010A1 (ja) | 溶接部材およびその製造方法 | |
JP7485242B1 (ja) | 溶接部材およびその製造方法 | |
WO2024063009A1 (ja) | 溶接部材およびその製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
ENP | Entry into the national phase |
Ref document number: 2013513324 Country of ref document: JP Kind code of ref document: A |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12884750 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14417075 Country of ref document: US |
|
ENP | Entry into the national phase |
Ref document number: 20157002933 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: MX/A/2015/001909 Country of ref document: MX |
|
WWE | Wipo information: entry into national phase |
Ref document number: IDP00201501672 Country of ref document: ID |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 12884750 Country of ref document: EP Kind code of ref document: A1 |