Effect of Al-Si Coating on Weldability of Press-Hardened Steels

  • RuiMing Chen
  • ChaoQun Zhang
  • Ming Lou
  • YongBing LiEmail author
  • Blair E. Carlson


Resistance spot welding (RSW) of Al-Si-coated PHS was undertaken, and the effect of Al-Si coating on nugget formation and mechanical properties was investigated. Press-hardened steel (PHS) has long been applied to automotive body structure construction to support mass and corresponding greenhouse gas emission reductions. PHS materials are often combined with an Al-Si coating applied as an oxidation barrier though unfortunately, the Al-Si coating poses a challenge to the resistance spot welding (RSW) of PHS containing stack-ups. As a newly developed coating for the hot stamping process, the property of Al-Si coating is different from base metal and traditional coatings, and the influence mechanism of Al-Si coating on the welding process is not clear. It would remain at nugget edge and might cause severe stress concentration. To investigate this problem, RSW of 1.5-mm Al-Si-coated PHS was undertaken, and the results indicate that a large portion of the Al-Si coating is extruded and forms a sharp notch close to the nugget edge during the welding process. During the post-weld cooling stage, a thin layer of residual coating is formed between the nugget and notch root. The mechanical performance of the welded joints is limited by the thin residual Al-Si layer which acts as a preexisting crack and supports the interfacial fracture. The presence of the Al-Si coating at the faying interface also significantly delays nugget formation, though it contributes to a larger nugget size by inhibiting expulsion events at the faying interface.


Al-Si coating press-hardened steel resistance spot welding ultrahigh-strength steel 



The authors would like to acknowledge the supports of GM Research and Development Center. The authors gratefully acknowledge the supports of National Natural Science Foundation of China (Grant Nos. U1564204, U1764251, and 51805323).


  1. 1.
    T. Senuma, Physical Metallurgy of Modern High Strength Steel Sheets, ISIJ Int., 2001, 41(6), p 520–532CrossRefGoogle Scholar
  2. 2.
    A.N. Bhagat, A. Singh, N. Gope, and T. Venugopalan, Development of Cold-rolled High-strength Formable Steel for Automotive Applications, Mater. Manuf. Processes, 2010, 25(1-3), p 202–205CrossRefGoogle Scholar
  3. 3.
    M. Alizadeh-Sh, S.P.H. Marashi, and M. Pouranvari, Microstructure-Properties Relationships in Martensitic Stainless Steel Resistance Spot Welds, Sci. Technol. Weld. Join., 2014, 19(7), p 595–602CrossRefGoogle Scholar
  4. 4.
    Y. Li, H.W. Liu, Y.H. Du, and P. Zhang, Applications and Developments of AHSS in Automobile Industry, Mater. Rev. A, 2011, 25(7), p 101–104 (in Chinese)Google Scholar
  5. 5.
    J. Lechler and M. Merklein, Hot Stamping of Ultra High Strength Steels as a Key Technology for Lightweight Construction, Mater. Sci. Technol., 2008, 9, p 1698–1709Google Scholar
  6. 6.
    H. Karbasian and A.E. Tekkaya, A Review on Hot Stamping, J. Mater. Process. Technol., 2010, 210(15), p 2103–2118CrossRefGoogle Scholar
  7. 7.
    M. Merklein, J. Lechler, and T. Stoehr, Characterization of Tribological and Thermal Properties of Metallic Coatings for hot Stamping Boron Manganese Steels. Proceedings of the Seventh International Conference on Coatings in Manufacturing Engineering, (2008), pp. 1–3Google Scholar
  8. 8.
    N.N., Stahl-Informations-Zentrum. Stahl im Automobil, Leicht und sicher, 2009.
  9. 9.
    L. Cho, H. Kang, C. Lee et al., Microstructure of Liquid Metal Embrittlement Cracks on Zn-Coated 22MnB5 Press-Hardened Steel, Scr. Mater., 2014, 90, p 25–28CrossRefGoogle Scholar
  10. 10.
    P. Drillet, R. Grigorieva, G. Leuillier, et al., Study of Cracks Propagation Inside the Steel on Press Hardened Steel Zinc Based Coatings. La Metallurgia Italiana 1 (2013)Google Scholar
  11. 11.
    C.W. Lee, D.W. Fan, I.R. Sohn et al., Liquid-Metal-Induced Embrittlement of Zn-Coated Hot Stamping Steel, Metall. Mater. Trans. A, 2012, 43(13), p 5122–5127CrossRefGoogle Scholar
  12. 12.
    S.S. Park, Y.M. Choi, D.G. Nam et al., Evaluation of Resistance Spot Weld Interfacial Fractures in Tensile-Shear Tests of TRIP 1180 Steels, J. Weld. Join., 2008, 26(6), p 81–91CrossRefGoogle Scholar
  13. 13.
    S.J. Chen, Y. Yu, C. Wang et al., Study on Spot Welding of UHSS Using IF Inverter and Servo Welding Gun System, Dianhanji Electr. Weld. Mach., 2010, 40(5), p 70–73Google Scholar
  14. 14.
    Y. Yu, C. Wang, S.J. Chen et al., Study on Intermediate Frequency Spot Welding Process of Hot Stamping High Strength Steel, Adv. Mater. Res., 2011, 339(1), p 375–378CrossRefGoogle Scholar
  15. 15.
    H.S. Choi, G.H. Park, W.S. Lim et al., Evaluation of Weldability for Resistance Spot Welded Single-Lap Joint Between GA780DP and Hot-Stamped 22MnB5 Steel Sheets, J. Mech. Sci. Technol., 2011, 25(6), p 1543–1550CrossRefGoogle Scholar
  16. 16.
    C.W. Ji, I. Jo, H. Lee et al., Effects of Surface Coating on Weld Growth of Resistance Spot-Welded Hot-Stamped Boron Steels, J. Mech. Sci. Technol., 2014, 28(11), p 4761–4769CrossRefGoogle Scholar
  17. 17.
    M. Windmann, A. Röttger, and W. Theisen, Formation of Intermetallic Phases in Al-Coated Hot-Stamped 22MnB5 Sheets in Terms of Coating Thickness and Si Content, Surf. Coat. Technol., 2014, 246(10), p 17–25CrossRefGoogle Scholar
  18. 18.
    W.J. Cheng and C.J. Wang, Microstructural Evolution of Intermetallic Layer in Hot-Dipped Aluminide Mild Steel with Silicon Addition, Surf. Coat. Technol., 2011, 205(19), p 4726–4731CrossRefGoogle Scholar
  19. 19.
    G. Eggeler, W. Auer, and H. Kaesche, On the Influence of Silicon on the Growth of the Alloy Layer During Hot Dip Aluminizing, J. Mater. Sci., 1986, 21(9), p 3348–3350CrossRefGoogle Scholar
  20. 20.
    M. Windmann, A. Röttger, and W. Theisen, Phase Formation at the Interface Between a Boron Alloyed Steel Substrate and an Al-Rich Coating, Surf. Coat. Technol., 2013, 226, p 130–139CrossRefGoogle Scholar
  21. 21.
    T. Heumann and S. Dittrich, Effect of Bevel Angle on Microstructure and Mechanical Property of Al/Steel Butt Joint Using Laser Welding-Brazing Method, Z. Met., 1959, 50, p 617–625Google Scholar
  22. 22.
    D.W. Fan and B.C. De Cooman, State-of-the-Knowledge on Coating Systems for Hot-Stamped Parts, Steel Res. Int., 2012, 83(5), p 412–413CrossRefGoogle Scholar
  23. 23.
    M. Pouranvari and S.P.H. Marashi, Failure Mode Transition in AHSS Resistance Spot Welds. Part I. Controlling Factors, Mater. Sci. Eng. A, 2011, 528(29-30), p 8337–8343CrossRefGoogle Scholar
  24. 24.
    M. Pouranvari, S.P.H. Marashi, and D.S. Safanama, Failure Mode Transition in AHSS Resistance Spot Welds. Part II: Experimental Investigation and Model Validation, Mater. Sci. Eng. A, 2011, 528(29–30), p 8344–8352CrossRefGoogle Scholar
  25. 25.
    T.K. Eller, L. Greve, M.T. Andres et al., Plasticity and Fracture Modeling of Quench-Hardenable Boron Steel with Tailored Properties, J. Mater. Process. Technol., 2014, 214(6), p 1211–1227CrossRefGoogle Scholar
  26. 26.
    B. Varbai, C. Sommer, M. Szabó et al., Shear Tension Strength of resistant Spot Welded Ultra High Strength Steels, Thin-Walled Struct., 2019, 142, p 64–73CrossRefGoogle Scholar
  27. 27.
    L. Ying, P. Andrea, A. Tim et al., Subcritical Heat Affected Zone Softening in Hot-Stamped Boron Steel During Resistance Spot Welding, Mater. Des., 2018, 155, p 170–184CrossRefGoogle Scholar

Copyright information

© ASM International 2020

Authors and Affiliations

  • RuiMing Chen
    • 1
  • ChaoQun Zhang
    • 1
  • Ming Lou
    • 1
  • YongBing Li
    • 1
    Email author
  • Blair E. Carlson
    • 2
  1. 1.Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, State Key Laboratory of Mechanical System and Vibration, School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghaiPeople’s Republic of China
  2. 2.Manufacturing Systems Research LabGeneral Motors Research & Development CenterWarrenUSA

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