Impact toughness variations of multi-pass, multi-layer CrMoV submerged arc welding weld metal

TIAN Hongwei; LU Li; ZHAO Chongyang; SHI Xiangwen; LI Kejian

doi:10.16511/j.cnki.qhdxxb.2021.22.004

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Journal of Tsinghua University(Science and Technology) ›› 2021, Vol. 61 ›› Issue (11) : 1273-1280. DOI: 10.16511/j.cnki.qhdxxb.2021.22.004

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Impact toughness variations of multi-pass, multi-layer CrMoV submerged arc welding weld metal

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Abstract

After post-welding heat treatment, the impact toughness of CrMoV weld metal from multi-pass, multi-layer submerged arc welding fluctuated greatly at room temperature. The microstructures and crack propagation paths of various samples were characterized using optical and scanning electron microscopes with the fracture surface morphology observed using a scanning electron microscope. In addition, the carbides in the matrix were analyzed using an Auger electron spectroscope. The results show that the reheated coarse-grained zone of the weld metal is the weakest microstructure component for the impact toughness and that the necklace-like distributed Fe₃C carbides and nonmetallic inclusions can lead to crack initiation. The location of the V-shaped notch in the weld metal is the key factor determining the impact absorbed energy. A larger distance between the V-shaped notch and the reheated coarse-grained zone in the direction along the crack propagation path increases the weld metal impact toughness.

Key words

multi-pass, multi-layer welding / impact toughness / crack initiation / carbides / notch location

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TIAN Hongwei, LU Li, ZHAO Chongyang, SHI Xiangwen, LI Kejian. Impact toughness variations of multi-pass, multi-layer CrMoV submerged arc welding weld metal[J]. Journal of Tsinghua University(Science and Technology). 2021, 61(11): 1273-1280 https://doi.org/10.16511/j.cnki.qhdxxb.2021.22.004

References

[1] 宁保群, 刘永长, 殷红旗, 等. 超高临界压发电厂锅炉管用铁素体耐热钢的发展现状与研究前景[J]. 材料导报, 2006, 20(12):83-86. NING B Q, LIU Y C, YIN H Q, et al. Development and investigation of ferritic heat resistant steels for boiler tube of the advanced power plants[J]. Materials Review, 2006, 20(12):83-86. (in Chinese)
[2] 罗永飞, 李占雷. 电站锅炉智能化焊接现状和发展趋势[J]. 电焊机, 2016, 46(3):7-10. LUO Y F, LI Z L. Current situation and development trend of intelligent welding of the power station boiler[J]. Electric Welding Machine, 2016, 46(3):7-10. (in Chinese)
[3] 蔡志鹏, 黄欣泉, 潘际銮, 等. 汽轮机焊接转子接头残余应力研究一:25Cr2Ni2MoV钢核电转子模拟件热处理前后残余应力的对比[J]. 热力透平, 2011, 40(3):159-164. CAI Z P, HUANG X Q, PAN J L, et al. Study on residual stress of joints of welded turbine rotors, part 1:Residual stress comparison before and after tempering of models of 25Cr2Ni2MoV steel nuclear turbine rotor[J]. Thermal Turbine, 2011, 40(3):159-164. (in Chinese)
[4] 袁军军, 禅志善, 曹睿, 等. 多层多道平焊接头冲击性能不稳定的原因分析[J]. 焊接学报, 2017, 38(5):100-103. YUAN J J, CHAN Z S, CAO R, et al. Analysis of impact toughness variation for flat position multi-pass weld joint[J]. Transactions of the China Welding Institution, 2017, 38(5):100-103. (in Chinese)
[5] 邓贤辉. 高强度焊缝金属韧性波动影响因素研究[J]. 材料开发与应用, 2012, 27(4):13-15, 20. (in Chinese)DENG X H. Research on factors affecting toughness fluctuation of high strength weld metals[J]. Development and Application of Materials, 2012, 27(4):13-15, 20. (in Chinese)
[6] QUINTANA M A, BABU S S, MAJOR J, et al. Weld metal toughness:Sources of variation[C]//Proceedings of the 8th International Pipeline Conference. Calgary, Canada, 2010:599-608.
[7] LI X D, MA X P, SUBRAMANIAN S V, et al. Influence of prior Austenite grain size on Martensite-Austenite constituent and toughness in the heat affected zone of 700 MPa high strength linepipe steel[J]. Materials Science and Engineering:A, 2014, 616:141-147.
[8] LI X D, FAN Y R, MA X P, et al. Influence of Martensite-Austenite constituents formed at different intercritical temperatures on toughness[J]. Materials & Design, 2015, 67:457-463.
[9] 陈剑虹, 曹睿. 焊缝金属解理断裂微观机理[J]. 金属学报, 2017, 53(11):1427-1444. CHEN J H, CAO R. Micromechanism of cleavage fracture of weld metals[J]. Acta Metallurgica Sinica, 2017, 53(11):1427-1444. (in Chinese)
[10] 杨锋平, 许彦, 曹国飞, 等. X80管线钢环焊缝力学性能及缺陷成因分析[J]. 压力容器, 2020, 37(1):68-73. YANG F P, XU Y, CAO G F, et al. Analysis of key mechanical properties and defect causes of X80 girth weld[J]. Pressure Vessel Technology, 2020, 37(1):68-73. (in Chinese)
[11] WANG X L, NAN Y R, XIE Z J, et al. Influence of welding pass on microstructure and toughness in the reheated zone of multi-pass weld metal of 550 MPa offshore engineering steel[J]. Materials Science and Engineering:A, 2017, 702:196-205.
[12] CHEN J H, CAO R. Micromechanism of cleavage fracture of metals:A comprehensive microphysical model for cleavage cracking in metals[M]. Oxford, UK:Elsevier, Butterworth-Heinemann, 2015.
[13] 阎澄, 陈剑虹, 罗永春. 低合金高强钢多层焊缝薄弱环节的组织及韧性[J]. 焊接学报, 1992, 13(1):21-25. YAN C, CHEN J H, LUO Y C. Microstructures and toughness of local brittle zone of HSLA steel multipass weld metals[J]. Transactions of the China Welding Institution, 1992, 13(1):21-25. (in Chinese)