Citation: | Liu Gang, Du Aiguo, Wang Weiqi, et al. Crack characteristic analysis of welded joints of 10MnNi2MoV low alloy steel pipe[J]. Welding & Joining, 2023(7):59 − 64. DOI: 10.12073/j.hj.20220706001 |
Welded joints of 10MnNi2MoV low alloy steel pipe in service in a power plant was taken as the research object, whose surface crack location, morphology, microstructure and fracture were studied and analyzed systematically. The results showed that serrated cracks were easy to produce in ЭА-395/9 surfacing layer near the cosmetic weld of welded joints of 10MnNi2MoV steel pipe, which usually expanded along the growth direction of columnar crystals. At the same time, it was easy to produce strip and granular precipitates, T-shaped grain boundaries and other microstructure and features in migration grain boundary near the surface of the surfacing layer. These microstructures provided internal conditions for formation of ductility dip cracking of welded joints of 10MnNi2MoV low alloy steel pipe. For welded joints of low alloy steel that have been in service for a long time in thermal power plants, ductility dip cracking is easy to occur in the surfacing layer of welded joints, and once the crack is formed, it will expand rapidly, which seriously threatens safe operation of power plant units.
[1] |
Kiser S D, Zhang R, Baker B A. A new welding material for improved resistance to ductility dip cracking [C]//Pine Mountain, Georgia, USA: Trends in Welding Research: Proceedings of the 8th International Conference, 2008: 639 − 644.
|
[2] |
Bendeich P J, Muránsky O, Hamelin C J, et al. Validated numerical analysis of residual stresses in safety relief valve (SRV) nozzle mock-ups: Influence of axial restraint on distortion and residual stress predictions[J]. Computational Materials Science, 2012, 62:285 − 288. doi: 10.1016/j.commatsci.2012.05.042
|
[3] |
Ramirez A J, Lippold J C. High temperature behavior of Ni-base weld metal: Part II–Insight into the mechanism for ductility dip cracking[J]. Materials Science and Engineering: A, 2004, 380(1-2):245 − 258. doi: 10.1016/j.msea.2004.03.075
|
[4] |
Collins M G, Ramirez A J, Lippold J C. An investigation of ductility-dip cracking in nickel-based weld metals–Part III[J]. Welding Journal, 2004, 83(2):39S − 49S.
|
[5] |
曹睿, 刘刚, 陈剑虹, 等. 镍基材料焊接中高温失塑裂纹DDC的生成机理及研究进展[J]. 焊接, 2018(7):7 − 13.
|
[6] |
Wang Jixiao, Wang Li, Wang Jun, et al. Study on sensitivity of Nb to high-temperature ductility dip crack of inconel 690[J]. China Welding, 2020, 29(4):54 − 59.
|
[7] |
冯杰才, 刘树磊, 骆传万, 等. 核电异种金属焊接材料及方法研究现状[J]. 焊接, 2022(3):52 − 57. doi: 10.12073/j.hj.20211001001
|
[8] |
陈静青, 陆皓, 陈辉, 等. 晶粒尺度对镍基高温合金的高温失塑裂纹敏感性的影响[J]. 电焊机, 2015, 45(6):21 − 25.
|
1. |
马良冬,刘震,任宗强,皮月亮,任义志,倪伟,欧阳康. 座舱盖作动筒接管嘴断裂研究及施胶粘接密封改进. 机械研究与应用. 2024(03): 111-114 .
![]() |