Effect of Heat Treatment on Microstructure and Mechanical Property of 30Si2MnCrMoV Welded Joint

Abstract:

The effect of different heat treatments on microstructure and mechanical property of 30Si2MnCrMoV steel weld specimen was studied in this paper．A stress relieving annealing on the specimen was carried out immediately after welding. And then two heat treatments were carried out on the specimen. Observation results showed that the original microstructure of 30Si2MnCrMoV welded joints was granular pearlite and the microstructure of weld bead was coarse martensite. Lots of tempered martensite exited in the weld specimen under quenching-tempering heat treatment, the carbide was coarse and the content of retained austenite was little. Under Quenching and Partitioning (Q&P) heat treatment, the content of retained austenite increased to 7% and a small number of coarse carbides existed. The determination of mechanical properties showed that, comparing with quenching-tempering process, the plasticity and toughness of weld specimen treated by Q&P was enhanced significantly, the percentage elongation increased 30%, the impact energy increased 25% ,the intensity reduced little and comprehensive mechanical property was excellent. The tensile fracture of 30Si2MnCrMoV steel under Q&P presented dimples. The retained austenite which exited along the lath boundaries of lath martensite was the main reason of the reduction of secondary cracks and the improvement of plasticity and toughness.

• Periodical: Advanced Materials Research (Volume 664)
• Pages: 754-759
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.664.754
• Online since: February 2013
• Authors: Q. Wang, C.L. Qi, D.L. Sun, X.L. Han, D.Q. Wang
• Keywords: Heat Treatment, Mechanical Property, Microstructure, Steel

References

[1] X.L. Lin, Y.H. Guo. China's Manganese Industry. Vol. 22(2004), p.41.

[2] M. G. Srinivas. Bulletin of Materials Science. Vol. 17(1994), p.73.

[3] B. B. Zhe, G. G. Hui. Journal of Iron and Steel Research. Vol. 18(2011), p.112.

[4] P. Zhang, W. Zhang, S.B. Wang. Aerospace Manufacturing Technology. Vol. 4(2011), p.12.

[5] Mohrbacher. Journal of Iron and Steel Research. Vol. 18(2011, p.893.

[6] P. Zhou, Shanghai Jiaotong University, Doctoral Dissertation, (2012).

[7] H.P. Liu. Shanghai Jiaotong University, Doctoral Dissertation, (2011).

[8] C. Dong, Y. L Chen, H.T. Jiang, D. Tang. Hot Working Technology. Vol. 38(2009), p.121.

[9] S. Zhu, Y.L. Kang, S.C. Li, K.K. Ren. Hot Working Technology. Vol. 40(2011), p.176.

[10] L.J. Wang, Q.W. Cai, W. Yui, H.B. Wu. Materials for Mechanical Engineering. Vol. 34(2010), p.1.

[11] H. Li, Z.L. Mii, C. Zhao, H.T. Jiang, S.S. Zhao. Hot Working Technology. Vol. 37(2008), p.39.

[12] C.Y. Wang, J. Shi, S. Liu, H. Dong. Iron & Steel. Vol. 45, (2010), p.79.