The new generation ultrahigh strength Q & P (Quenching and Partitioning) steel owns both high strength and fine ductility, it has wide application prospect in automobile industry. However, after carrying out resistance spot welding experiment on the galvanized high strength Q & P980 steel plates, cracks were detected on the surface of joint, former researches showed that the cracks were caused by liquid metal embrittlement (LME), that was the steel plates were intergranular fractured under the effect of liquid zinc and stress. Experiment results indicated that process parameters (including welding current, welding time and electrode force) and process conditions (including electrode morphology, pressure mode and electrode alignment) were found to have influence on the LME cracks of joints. Thus, there is a possibility to reduce the crack sensibility by adjusting the process parameters and conditions.
KONG Liang
,
LING Zhanxiang
,
WANG Ze
,
WANG Min
,
PAN Hua
,
LEI Ming
. Study on influence factors of liquid metal embrittlement cracks in resistance spot welded joints of galvanized Q & P980 steel[J]. Transactions of The China Welding Institution, 2018
, 39(7)
: 37
-41
.
DOI: 10.12073/j.hjxb.2018390171
[1] 刁可山, 蒋浩民, 陈新平. 基于成形特性的宝钢QP980试验研究及典型应用[J]. 锻压技术, 2012, 37(6):113-115. Diao Keshan, Jiang Haomin, Chen Xinping. Research and typical application of QP980 steel produced by BaoSteel based on formability[J]. Forging & Stamping Technology, 2012, 37(6):113-115.[DOI:10.3969/j.issn.1000-3940.2012.06.029]
[2] Pouranvari M, Marashi S P H. Critical review of automotive steels spot welding:process, structure and properties[J]. Science and Technology of Welding and Joining, 2013, 18(5):361-403.[DOI:10.1179/1362171813Y.0000000120]
[3] Kim Y G, Kim I J, Kim J S, et al. Evaluation of surface crack in resistance spot welds of Zn-coated steel[J]. Materials Transactions, 2014, 55(1), 171-175.[DOI:10.2320/matertrans.M2013244]
[4] Ashiri R, Haque M A, Ji C W, et al. Supercritical area and critical nugget diameter for liquid metal embrittlement of Zn-coated twining induced plasticity steels[J]. Scripta Materialia, 2015, 109, 6-10.[DOI:10.1016/j.scriptamat.2015.07.006]
[5] Ashiri R, Shamanian M, Salimijazi H R, et al. Liquid metal embrittlement-free welds of Zn-coated twinning induced plasticity steels[J]. Scripta Materialia, 2016, 114, 41-47.[DOI:10.1016/j.scriptamat.2015.11.027]
