PRODUCTION METHOD FOR RESISTANCE SPOT WELDED JOINT

WIPO Patent Application WO/2018/181231

A1

The present invention is for producing a resistance spot welded joint that comprises a stack of: aluminum sheets; and at least one type of steel sheet selected from among plated steel sheets, cold-rolled steel sheets, and hot-rolled steel sheets. The sheets are combined such that one of the outermost sheets is an aluminum sheet and the other is a steel sheet. The present invention includes: a first electrification step that is for applying a current I1 (kA) for an electrification time t1 (ms); an electrification suspension step that is after the first electrification step and is for suspending electrification for an electrification suspension time tc (ms); and a second electrification step that is after the electrification suspension step and is for applying a current I2 (kA) for an electrification time t2 (ms). The present invention satisfies expressions (1)-(6), in which TFe (mm) is the total thickness of the stacked steel sheets, RFe (mm) is the radius of curvature of the tip of an electrode that is made to contact the steel sheets, and DFe (mm) is the diameter of the tip of the electrode that is made to contact the steel sheets: (1) I1t2, (3) t1≥40, (4) tc≥5, (5) 3+0.04×√(I1 2×t1×TFe/DFe)≤tc≤495+√(I1 2×t1×TFe/DFe), and (6) RFe≥20.

SAWANISHI CHIKAUMI (JP)
MATSUDA HIROSHI (JP)
IKEDA RINSEI (JP)

PCT/JP2018/012259

October 04, 2018

March 27, 2018

Click for automatic bibliography generation  

JFE STEEL CORP (JP)

B23K11/20; B23K11/11; B23K11/18; B23K11/30

JP2013151018A	2013-08-08
JP2010172946A	2010-08-12
JPH11156556A	1999-06-15
JP2013111586A	2013-06-10

KUMASAKA Akira et al. (JP)

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