RESISTANCE SPOT WELDING METHOD

Title:

RESISTANCE SPOT WELDING METHOD

Document Type and Number:

WIPO Patent Application WO/2015/099192

Kind Code:

A1

Abstract:

The objective of the invention is to provide a resistance spot welding method with which a nugget having a suitable diameter can be obtained even under special welding conditions, without increasing the energization time and without the generation of expulsions. The invention is a resistance spot welding method in which an energization pattern is divided into multi-stage steps having two or more stages, and in which test welding and main welding are performed. In the test welding, the energization is performed using a constant current that has a different current value for each step, and the time variation of the instantaneous amount of heat generated per unit volume, and the accumulated amount of heat generated per unit volume are stored as target values. In the main welding, if the amount of time variation of the instantaneous amount of heat generated per unit volume deviates from the results of the test welding during any step, the amount of energization is controlled in such a way that the difference is compensated for during the remaining energization time in said step. The configuration is such that in the test welding, if the energization current in a first step is Ia and the energization current in second and subsequent steps is Ix, the relationship 0.3 × Ix ≤ Ia < Ix is satisfied.

Inventors:

SAWANISHI CHIKAUMI (JP)
OKITA YASUAKI (JP)
IKEDA RINSEI (JP)

Application Number:

PCT/JP2014/084741

Publication Date:

July 02, 2015

Filing Date:

December 22, 2014

Export Citation:

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Assignee:

JFE STEEL CORP (JP)

International Classes:

B23K11/24; B23K11/11

Domestic Patent References:

WO2014136507A1	2014-09-12
WO2014156290A1	2014-10-02

Foreign References:

JP2010221284A	2010-10-07
JP2010247215A	2010-11-04
JP2010240740A	2010-10-28
JPH1133743A	1999-02-09
JPH09216071A	1997-08-19
JPH1094883A	1998-04-14
JPH1133743A	1999-02-09
JP2013047180A	2013-03-07

Other References: