Effect of Heat Imput on Microstructure and Toughness of High Strength Bridge Steel

Abstract:

The coarse grain heat affected zone(CGHAZ) at different parameters t8/5 of high-strength bridge steel Q460q were simulated with thermal simulation machine. the microstructure of CGHAZ and the effect of granular bainite on the toughness were analyzed in this paper.The results show that: When t8/5<60s, lath bainite and granular bainite intertwine, and the quantity of strip M-A constituents in granular bainite decreased, so toughness is higher.When t8/5>60s, the quantity of eutectoid ferrite and granular bainite increased, coarse M-A constituent resulting in the grain size of effective crack propagation becoming coarser and toughness decreased significantly.

• Periodical: Advanced Materials Research (Volumes 194-196)
• Pages: 255-258
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.194-196.255
• Online since: February 2011
• Authors: Kun Ning Jia
• Keywords: Granular Bainite, M-A Constituent, Toughness

References

[1] Dewei Tian , Bainian Qian , Zhongyao Si. Etching Methodf or The Tmage Measured by M-A Phase. physics test in 1994, the second phase, p.35. in chinese.

[2] Dewei Tian , Bainian Qian , Zhongyao Si. Comparative Study of the Corrosion Method by Image Elements of M-A . Physical examination - Physical Testing, Vol. 30. No. 1 (1994). in chinese.

[3] Guiquan Yin, Xianzhu Cha, BaizhongLu . STE355 Steel Microstructure after Welding in the Grain Shell and its Effect on Toughness. Welding Technology, Vol. 24 No2(2003), p.55. in Chinese.

[4] Lin Zhao , Xudong Zhang , Wuzhu Chen. Study on HAZ Toughness of 800 MPa Low Alloy Steel . Metal Technology, Vol. 41 No. 4(2005), p.392. in chinese.

[5] Tian-Hui Xi, Chen Xiao, Chen Yan Tang. Zr microalloyed HSLA steel coarse grain heat affected zone microstructure and properties. Special steel, Vol. 26. No2 (2005), 16~19. In chinese.