Title:
METHOD FOR WELDING ZINC-COATED HIGH-STRENGTH STEEL RESISTANCE SPOT HAVING GOOD JOINT PROPERTIES
Document Type and Number:
WIPO Patent Application WO/2018/082425
Kind Code:
A1
Abstract:
A method for welding a zinc-coated high-strength steel resistance spot having good joint properties, which comprises using three welding pulses within one spot-welding cycle: a first welding pulse and a second welding pulse are used to generate a nugget and suppress generation of liquid-metal-embrittlement (LME) cracks, wherein the first welding pulse generates a nugget having a diameter of 3.75T1/2—4.25T1/2, wherein T is thickness of a plate; the second welding pulse makes the nugget grow slowly; a third welding pulse is a slow-cooling pulse, which is used to improve plasticity of solder joints. For the first welding pulse, a welding current I1 of the first welding pulse is obtained by means of setting a time t1 of the first welding pulse and by means of an experiment, wherein the welding current I1 of the first welding pulse is a welding current corresponding to when a nugget having a diameter of 3.75T1/2—4.25T1/2 is generated; a welding current I2 and time t2 of the second welding pulse and a welding current I3 and time t3 of the third welding pulse are calculated from the welding current I1 and time t1 of the first welding pulse. The method for welding a zinc-coated high-strength steel resistance spot may effectively suppress the problem of LME cracks which occur during spot welding of a high-strength zinc-coated steel sheet, while increasing plasticity of the solder joints, thereby increasing the probability of a button fracture occurring in the solder joints during breakage detection. Therefore, joints of high-strength zinc-coated steel sheet spot welding having more reliable quality and superior performance are acquired, and the method provides useful guidance for high-strength zinc-coated steel plate welding production.
Inventors:
LEI MING (CN)
PAN HUA (CN)
ZUO DUNGUI (CN)
SU YONGCHAO (CN)
JIANG HAOMIN (CN)
SHI LEI (CN)
PAN HUA (CN)
ZUO DUNGUI (CN)
SU YONGCHAO (CN)
JIANG HAOMIN (CN)
SHI LEI (CN)
Application Number:
PCT/CN2017/104710
Publication Date:
May 11, 2018
Filing Date:
September 30, 2017
Export Citation:
Assignee:
BAOSHAN IRON & STEEL (CN)
International Classes:
B23K11/11
Foreign References:
| CN104722905A | 2015-06-24 | |||
| CN105636735A | 2016-06-01 | |||
| CN102500901A | 2012-06-20 | |||
| CN102950373A | 2013-03-06 | |||
| CN105358284A | 2016-02-24 | |||
| PL395525A1 | 2013-01-07 | |||
| CN102489859A | 2012-06-13 | |||
| CN102500936A | 2012-06-20 |
Other References:
ROUHOLAH ASHIRI ET AL.: "liquid metal embrittlement-free welds of Zn-coated twinning induced plasticity steels", SCRIPTA MATERIALIA (SCRIPTA MATERIALIA, vol. 114, 2016, pages 41 - 47, XP029389443, DOI: doi:10.1016/j.scriptamat.2015.11.027
See also references of EP 3536435A4
See also references of EP 3536435A4
Attorney, Agent or Firm:
WATSON & BAND INTELLECTUAL PROPERTY AGENT LTD. (CN)
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