Advanced high strength steels used in automotive structural components are commonly protected using zinc coatings. However, the steel/zinc system creates the potential for liquid metal embrittlement (LME) during welding. Although LME cracks are known to form, limited research has found any detrimental impact of LME cracks on weld strength. In this work, a comparison of zinc coated and uncoated advanced high strength steel joints showed LME decreased strength in welds from transformation induced plasticity type microstructures and an 1100 MPa ultimate tensile strength by 43.6%. LME cracks were observed to propagate until final fracture. However, only cracks located in the periphery of the weld area were found contribute to a loss in strength.
CreutzigBF, JochemP, EdelenboschOY, Transport: a roadblock to climate change mitigation?Science. 2015; 350:911–912. (80-.). doi: 10.1126/science.aac8033
5.
ParkesD, WesterbaanD, NayakSS, Tensile properties of fiber laser welded joints of high strength low alloy and dual-phase steels at warm and low temperatures. Mater Des. 2014; 56:193–199. doi: 10.1016/j.matdes.2013.10.087
6.
ParkesD, XuW, WesterbaanD, Microstructure and fatigue properties of fiber laser welded dissimilar joints between high strength low alloy and dual-phase steels. Mater Des. 2013; 51:665–675. doi: 10.1016/j.matdes.2013.04.076
7.
XuW, WesterbaanD, NayakSS, Tensile and fatigue properties of fiber laser welded high strength low alloy and DP980 dual-phase steel joints. Mater Des. 2013; 43:373–383. doi: 10.1016/j.matdes.2012.07.017
8.
KimchiM, PhillipsDH.Resistance spot welding, fundamentals and applications for the automotive industry. Columbus (OH): Morgan Claypool Publ; 2017.
9.
InaK, KoizumiH.Penetration of liquid metals into solid metals and liquid metal embrittlement. Mater Sci Eng A. 2004; 387–389:390–394. doi: 10.1016/j.msea.2004.05.042
10.
JosephB, BarbierF, DagouryG, Rapid penetration of liquid Bi along Cu grain boundaries. Scr Mater. 1998; 39:775–781. doi: 10.1016/S1359-6462(98)00230-9
11.
KimYG, KimIJ, KimJS, Evaluation of surface crack in resistance spot welds of Zn-coated steel. Mater Trans. 2014; 55:171–175. doi: 10.2320/matertrans.M2013244
JungG, WooIS, SuhDW, Liquid Zn assisted embrittlement of advanced high strength steels with different microstructures. Met Mater Int. 2016; 22:187–195. doi: 10.1007/s12540-016-5579-7
15.
BealC, KleberX, FabregueD, Embrittlement of a zinc coated high manganese TWIP steel. Mater Sci Eng A. 2012; 543:76–83. doi: 10.1016/j.msea.2012.02.049
16.
MarashiP, PouranvariM, SanaeeSMH, Relationship between failure behaviour and weld fusion zone attributes of austenitic stainless steel resistance spot welds. Mater Sci Technol. 2008; 24:1506–1512. Available from: https://www.tandfonline.com/doi/full/10.1179/174328408X262418
17.
ZhangH, QiuX, XingF, Failure analysis of dissimilar thickness resistance spot welded joints in dual-phase steels during tensile shear test. Mater Des.2014; 55:366–372. Available from: http://dx.doi.org/10.1016/j.matdes.2013.09.040
18.
Russo SpenaP, De MaddisM, D'AntonioG, Weldability and monitoring of resistance spot welding of Q &P and TRIP steels. Metals (Basel). 2016; 6:270. Available from: http://www.mdpi.com/2075-4701/6/11/270 doi: 10.3390/met6110270
19.
KhanMI, KuntzML, ZhouY.Effects of weld microstructure on static and impact performance of resistance spot welded joints in advanced high strength steels. Sci Technol Weld Join. 2008; 13:294–304. Available from: http://www.tandfonline.com/doi/full/10.1179/174329308X271733
PouranvariM.Critical assessment: dissimilar resistance spot welding of aluminium/steel: challenges and opportunities. Mater Sci Technol. (United Kingdom). 2017; 33:1705–1712. doi: 10.1080/02670836.2017.1334310
23.
ChoiD-Y, UhmS-H, EnloeCM, Liquid metal embrittlement of resistance spot welded 1180TRIP steel- effects of crack geometry on weld mechanical performance. Mater Sci Technol. 2017: 454–462.
24.
BenlatrecheY, Ghassemi-ArmakiH, DuchetM, Spot-Weld integrity of Zn-coated 3rd Gen. advanced high strength steel in presence of LME. Int Automot Body Congr. (IABC 2017 Dearborn). 2017: 9–18.
25.
KimYG, KimIJ, KimJS, Evaluation of surface crack in resistance spot welds of Zn-coated steel. Japan inst. Met Mater. 2014; 55:171–175.
26.
American Welding Society. American Welding Society: Test Method for Evaluating the Resistance Spot Welding Behavior of Automotive Sheet Steel Materials (AWS D 8.9M). 2012. p. 1–107.
27.
BoriwalL, SarviyaRM, MahapatraMM.Failure modes of spot welds in quasi - static tensile - shear loading of coated steel sheets. Shear l Mater Today Proc. 2017; 4:3672–3677. Available from: http://dx.doi.org/10.1016/j.matpr.2017.02.261.
AshiriR, HaqueMA, JiC-W, . Supercritical area and critical nugget diameter for liquid metal embrittlement of Zn-coated twining induced plasticity steels. Scr. Mater.2015; 109:6–10.
30.
ChoL, KangH, LeeC, Microstructure of liquid metal embrittlement cracks on Zn-coated 22MnB5 press-hardened steel. Scr. Mater. 2014; 90-91:25–28. Available from: http://dx.doi.org/10.1016/j.scriptamat.2014.07.008
