Highly Enhanced Cross Tensile Strength of the Resistance Spot Welded Medium Manganese Steel by Optimized Post-heating Pulse

  • Yuanfang Wang
  • Kai DingEmail author
  • Bingge Zhao
  • Yuanheng Zhang
  • Guanzhi Wu
  • Tao Wei
  • Hua PanEmail author
  • Yulai GaoEmail author
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)


The role of the post-heating pulse in the microstructure evolution and cross tensile strength (CTS) variation of the resistance spot welded 7Mn medium manganese steel (MMS) was studied. The results showed that the microstructure in the nugget fabricated by 4.0 kA was tempered martensite, yet the one by 4.5 kA was martensite. According to the cross tensile test results, the CTS was improved from 2.0 to 3.0 kN with the current of post-heating pulse increased from 2.5 to 4.0 kA, while the strength decreased to 1.8 kN when the current increased to 4.5 kA. In particular, the post-heating pulse over 4.0 kA to result in the nugget remelting and subsequently martensite formation were the crucial factors to decrease the CTS. The enhancement of CTS for the resistance spot welded 7Mn MMS could be attributed to the microstructure transition from martensite to tempered martensite.


Medium manganese steel Resistance spot welding Cross tensile strength Post-heating pulse 



This work was supported by the National Natural Science Foundation of China (Grant no. U1760102), the State Key Laboratory of Development and Application Technology of Automotive Steels (Baosteel Group) and the financial support by the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning.


  1. 1.
    Yu S, Du LX, Hu J, Misra RDK (2018) Effect of hot rolling temperature on the microstructure and mechanical properties of ultra-low carbon medium manganese steel. Mater Sci Eng, A 731:149–155CrossRefGoogle Scholar
  2. 2.
    Lee YK, Han J (2015) Current opinion in medium manganese steel. Mater Sci Technol 31(7):843–856CrossRefGoogle Scholar
  3. 3.
    Chen J, Lv M, Tang S, Liu Z, Wang G (2015) Correlation between mechanical properties and retained austenite characteristics in a low-carbon medium manganese alloyed steel plate. Mater Charact 106:108–111CrossRefGoogle Scholar
  4. 4.
    Cao WQ, Wang C, Shi J, Wang MQ, Hui WJ, Dong H (2011) Microstructure and mechanical properties of Fe–0.2C–5Mn steel processed by ART-annealing. Mater Sci Eng A 528(22-23):6661–6666CrossRefGoogle Scholar
  5. 5.
    Ma Y (2017) Medium-manganese steels processed by austenite-reverted-transformation annealing for automotive applications. Mater Sci Technol 33(15):1713–1727CrossRefGoogle Scholar
  6. 6.
    Zou Y, Xu YB, Hu ZP, Gu XL, Peng F, Tan XD, Chen SQ, Han DT, Misra RDK, Wang GD (2016) Austenite stability and its effect on the toughness of a high strength ultra-low carbon medium manganese steel plate. Mater Sci Eng A 675:153–163CrossRefGoogle Scholar
  7. 7.
    Zhang Y, Wang L, Findley KO, Speer JG (2017) Influence of temperature and grain size on austenite stability in medium manganese steels. Metall Mater Trans A 48(5):2140–2149CrossRefGoogle Scholar
  8. 8.
    Zou Y, Xu YB, Hu ZP, Gu XL, Peng F, Tan XD, Chen SQ, Han DT, Misra RDK, Wang GD (2016) Austenite stability and its effect on the toughness of a high strength ultra-low carbon medium manganese steel plate. Mater Sci Eng A 675:153–163CrossRefGoogle Scholar
  9. 9.
    Li ZC, Ding H, Misra RDK, Cai ZH, Li HX (2016) Microstructural evolution and deformation behavior in the Fe-(6, 8.5)Mn-3Al-0.2C TRIP steels. Mater Sci Eng A 672:161–169CrossRefGoogle Scholar
  10. 10.
    Li SS, Yang SL, Lu Q, Luo HW, Tao W (2019) A novel shim-assisted resistance spot welding process to improve weldability of medium-Mn transformation-induced plasticity steel. Metall Mater Trans B 50(1):585–585CrossRefGoogle Scholar
  11. 11.
    Park G, Kim K, Uhm S, Lee C (2019) A comparison of cross-tension properties and fracture behavior between similar and dissimilar resistance spot-weldments in medium-Mn TRIP steel. Mater Sci Eng A 752:206–216CrossRefGoogle Scholar
  12. 12.
    Pouranvari M, Marashi SPH (2013) Critical review of automotive steels spot welding: process, structure and properties. Sci Technol Weld Joining 18(5):361–403CrossRefGoogle Scholar
  13. 13.
    Saha DC, Cho Y, Park YD (2013) Metallographic and fracture characteristics of resistance spot welded TWIP steels. Sci Technol Weld Joining 18(8):711–720CrossRefGoogle Scholar
  14. 14.
    Wang B, Hua L, Wang X, Li J (2016) Effects of multi-pulse tempering on resistance spot welding of DP590 steel. Int J Adv Manuf Technol 86:2927–2935CrossRefGoogle Scholar
  15. 15.
    Wan X, Wang Y, Fang C (2014) Welding defects occurrence and their effects on weld quality in resistance spot welding of AHSS steel. ISIJ Int 54(8):1883–1889CrossRefGoogle Scholar
  16. 16.
    Heo NH, Nam JW, Heo YU, Kim SJ (2013) Grain boundary embrittlement by Mn and eutectoid reaction in binary Fe–12Mn steel. Acta Mater 61(11):4022–4034CrossRefGoogle Scholar
  17. 17.
    Kuzmina M, Ponge D, Raabe D (2015) Grain boundary segregation engineering and austenite reversion turn embrittlement into toughness: example of a 9 wt.% medium Mn steel. Acta Mater 86:182–192CrossRefGoogle Scholar
  18. 18.
    Chabok A, Van Der Aa E, De Hosson JTM, Pei YT (2017) Mechanical behavior and failure mechanism of resistance spot welded DP1000 dual phase steel. Mater Des 124:171–182CrossRefGoogle Scholar
  19. 19.
    Chao YJ (2003) Failure mode of spot welds: interfacial versus pullout. Sci Technol Weld Joining 8(2):133–137Google Scholar
  20. 20.
    Li H, Duan Q, Zhang P, Zhang Z (2019) The relationship between strength and toughness in tempered steel: trade-off or invariable? Adv Eng Mater 21(4).
  21. 21.
    Li HF, Wang SG, Zhang P, Qu RT, Zhang ZF (2018) Crack propagation mechanisms of AISI 4340 steels with different strength and toughness. Mater Sci Eng A 729:130–140CrossRefGoogle Scholar

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© The Minerals, Metals & Materials Society 2020

Authors and Affiliations

  1. 1.School of Materials Science and EngineeringCenter for Advanced Solidification Technology (CAST), Shanghai UniversityShanghaiPeople’s Republic of China
  2. 2.State Key Laboratory of Development and Application Technology of Automotive SteelsShanghaiPeople’s Republic of China
  3. 3.Automobile Steel Research Institute, R&D Center, Baoshan Iron & Steel Co., Ltd.ShanghaiPeople’s Republic of China

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