Homogeneous specimens of the laser-arc hybrid welding heated affected zone (HAZ) of low alloy high strength steel were prepared by welding thermal simulation technology. The instrumented impact test and microstructure characterization technologies were used to analysis the relationship between the microstructure and toughness of the simulated specimens. The results showed that the simulated coarse grained HAZ (CGHAZ) and fine grained HAZ (FGHAZ) composed of lath martensite (LM) and the inter-critical HAZ (ICHAZ) compose of LM and grain boundary carbide, the sub-critical HAZ (SCHAZ) is comprised of tempered martensite. The peak temperature has little effect on the crack initiation energy, but large effect on the crack propagation energy. The simulated ICHAZ and CGHAZ specimens have poor resistance to crack propagation. When the peak temperature is the same, the impact energy of the simulated CGHAZ specimens have little change with various the cooling rates. The peak temperature mainly affects the crack stable propagation energy and the crack stable propagation energy decrease as the peak temperature increase. The fracture process of the simulated CGHAZ specimen was controlled by the crack propagation, and the block was the microstructure unit controlling the crack stable propagation.
BAO Liangliang
,
PAN Chunyu
,
LIU Fujian
,
ZHANG Xinming
,
HAN Tao
. Microstructure and impact toughness of laser-arc hybrid welding simulated heat affected zone of high strength low alloy steel[J]. Transactions of The China Welding Institution, 2022
, 43(5)
: 90
-97
.
DOI: 10.12073/j.hjxb.20210817001
[1] Zeng Huilin, Xu Yuanbin, Wang Changjiang, et al. Research on laser-arc hybrid welding technology for long-distance pipeline construction[J]. China Welding, 2018, 27(3): 53 ? 58.
[2] 严春妍, 易思, 张浩, 等. S355钢激光-MIG复合焊接头显微组织和残余应力[J]. 焊接学报, 2020, 41(6): 12 ? 18
Yan Chunyan, Yi Si, Zhang Hao, et al. Investigation of microstructure and stress in laser-MIG hybrid welded S355 steel plates[J]. Transactions of the China Welding Institution, 2020, 41(6): 12 ? 18
[3] 滕彬, 李小宇, 雷振, 等. 低合金高强钢激光-电弧复合热源焊接冷裂纹敏感性分析[J]. 焊接学报, 2010, 31(11): 61 ? 64
Teng Bin, Li Xiaoyu, Lei Zhen, et al. Analysis on cold crack sensitivity of low alloy high strength steel weld by laser-arc hybrid welding[J]. Transactions of the China welding institution, 2010, 31(11): 61 ? 64
[4] 王治, 王春明, 胡伦骥, 等. 激光-电弧复合焊接的应用[J]. 电焊机, 2006, 36(2): 38 ? 41
Wang Zhi, Wang Chunming, Hu Lunji, et al. Application of laser-arc hybrid welding in industry[J]. Electric Welding Machine, 2006, 36(2): 38 ? 41
[5] Zhang Shenghai, Shen Yifu, Qiu Huijuan. The technology and welding joint properties of hybrid laser-TIG welding on thick plate[J]. Optics Laser Technology, 2013(48): 381 ? 388.
[6] Hao Kangda, Zhang Chen, Zeng Xiaoyan, et al. Effect of heat input on weld microstructure and toughness of laser-arc hybrid welding of martensitic stainless steel[J]. Journal of Materials Processing Technology, 2017(245): 7 ? 14.
[7] Subashini L, Prabhakar K V P, Ghosh S, et al. Comparison of laser-MIG hybrid and autogenous laser welding of M250 maraging steel thick sections-understanding the role of filler wire addition[J]. The International Journal of Advanced Manufacturing Technology, 2020, 107(3): 1581 ? 1594.
[8] Bao Liangliang, Wang Yong, Han Tao. Microstructure and mechanical characterization of high strength low alloy steel welded joint by hybrid laser arc welding[C]//International Conference on Mechanical Engineering, Materials Science and Civil Engineering 2019. IOP Conference Series Materials science and Engineering. 2020: 12045.
[9] Bao Liangliang, Wang Yong, Han Tao. Study on microstructure-toughness relationship in heat affected zone of EQ70 steel by laser-arc hybrid welding[J]. Materials Characterization, 2020, 171: 110788.
[10] 鲍亮亮, 王勇, 张洪杰, 等. EQ70钢激光电弧复合焊焊接热循环及其对热影响区组织演变的影响[J]. 焊接学报, 2021, 42(3): 26 ? 33
Bao Liangliang, Wang Yong, Zhang Hongjie, et al. Welding thermal cycle of the laser-arc hybrid welding of the EQ70 steel and its effects on the microstructure evolution of the heat affected zone[J]. Transactions of the China Welding Institution, 2021, 42(3): 26 ? 33
[11] Swarr T, Kruss G. The effect of structure on the deformation of as-quenched and tempered martensite in an Fe-0.2 pct C alloy[J]. Metallurgical Transactions A, 1976(7): 41 ? 48.
[12] Inoue T, Matsuda S, Okamra Y, et al. The fracture of a low carbon tempered martensite[J]. Transactions of the Japan Institute of Metals, 1970, 11(1): 36 ? 43.
[13] Morris J W. On the ductile-brittle transition in lath martensitic steel[J]. Isij International, 2011, 51(10): 1569 ? 1575.
