Abstract
An ultra-low carbon steel plate with the yield strength of 690 MPa was produced in the laboratory. The coarse-grain heat-affected zone (CGHAZ) was simulated on a thermal simulator based on the welding heat inputs of 25 kJ/cm and 100 kJ/cm, under which the microstructure and impact toughness were characterized compared with the base metal (BM). The results showed that the investigated steel exhibited a favorable low-temperature impact toughness at the heat input of 25 kJ/cm. Although high heat input was not conducive to the impact toughness, the average impact energy can still reach ⁓40 J at − 20℃ at the heat input of 100 kJ/cm. The welding thermal cycle led to the formation of more low-angle boundaries in the prior austenite grains, which was not conducive to the crack arrest behavior, resulting in a significant decrease of toughness in CGHAZ. Obvious decrease of high-angle boundaries in CGHAZ was mainly responsible for the deterioration of total impact absorbed energy. Besides, the martensite-austenite (M-A) constituents provided favorable conditions for crack initiation. In general, the mechanism of impact toughness deterioration of CGHAZ under high heat input condition was discussed in detail. The microstructure and low-temperature impact toughness of CGHAZ under different heat inputs can provide a theoretical basis for the research in 690 MPa ultra-low carbon high-strength microalloyed steels.
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References
Uemori R, Inoue T, Ichikawa K et al (2012) Steels for marine transportation and construction, Nippon Steel Technical Report:37–46
Xi X, Wang J, Chen L et al (2020) On the role of Cu addition in toughness improvement of coarse grained heat affected zone in a low carbon high strength steel. J Mater Sci 55:10863–10877
Cao R, Li J, Liu DS et al (2015) Micromechanism of decrease of impact toughness in coarse-grain heat-affected zone of HSLA steel with increasing welding heat input. Metall Mater Trans A 46:2999–3014
Hu J, Du LX, Wang JJ et al (2013) Effect of welding heat input on microstructures and toughness in simulated CGHAZ of V-N high strength steel. Mater Sci Eng A 577:161–168
Lan L, Kong X, Chang Z et al (2017) Microstructure, composition, and impact toughness across the fusion line of high-strength bainitic steel weldments. Metall Mater Trans A 48:4140–4153
Kang YJ, Jeong SH, Kang JH et al (2016) Factors affecting the inclusion potency for acicular ferrite nucleation in high-strength steel welds. Metall Mater Trans A 47:2842–2854
Gordienko AI, Derevyagina LS, Malikov AG et al (2020) The effect of the initial microstructure of the X70 low-carbon microalloyed steel on the heat affected zone formation and the mechanical properties of laser welded joints. Mater Sci Eng A 797:2–8
Xiong ZH, Liu SL, Wang XM et al (2015) The contribution of intragranular acicular ferrite microstructural constituent on impact toughness and impeding crack initiation and propagation in the heat-affected zone (HAZ) of low-carbon steels. Mater Sci Eng A 636:117–123
Wan XL, Wei R, Wu KM (2010) Effect of acicular ferrite formation on grain refinement in the coarse-grained region of heat-affected zone. Mater Charact 61:726–731
Wang X, Wang C, Kang J et al (2020) Improved toughness of double-pass welding heat affected zone by fine Ti–Ca oxide inclusions for high-strength low-alloy steel. Mater Sci Eng A 780:2–10
Lan L, Qiu C, Zhao D et al (2013) Effect of reheat temperature on continuous cooling bainite transformation behavior in low carbon microalloyed steel. J Mater Sci 48:4356–4364
Haslberger P, Holly S, Ernst W et al (2018) Microstructure and mechanical properties of high-strength steel welding consumables with a minimum yield strength of 1100 MPa. J Mater Sci 53:6968–6979
Xie H, Du LX, Hu J et al (2015) Effect of thermo-mechanical cycling on the microstructure and toughness in the weld CGHAZ of a novel high strength low carbon steel. Mater Sci Eng A 639:482–488
Kwak K, Mayama T, Mine Y et al (2016) Micro-tensile behaviour of low-alloy steel with bainite/martensite microstructure. ISIJ Int 56:2313–2319
Lan L, Qiu C, Zhao D et al (2011) Microstructural characteristics and toughness of the simulated coarse grained heat affected zone of high strength low carbon bainitic steel. Mater Sci Eng A 529:192–200
Cui B, Peng Y, Zhao L et al (2016) Effect of heat input on microstructure and toughness of coarse grained heat affected zone of Q890 Steel. ISIJ Int 56:132–139
Shi M, Zhang P, Zhu F (2014) Toughness and microstructure of coarse grain heat affected zone with high heat input welding in Zr-bearing low carbon steel. ISIJ Int 54:188–192
Lan L, Qiu C, Zhao D et al (2012) Analysis of martensite–austenite constituent and its effect on toughness in submerged arc welded joint of low carbon bainitic steel. J Mater Sci 47:4732–4742
Lan L, Qiu C, Zhao D et al (2012) Analysis of microstructural variation and mechanical behaviors in submerged arc welded joint of high strength low carbon bainitic steel. Mater Sci Eng A 558:592–601
Li C, Wang Y, Han T et al (2010) Microstructure and toughness of coarse grain heat-affected zone of domestic X70 pipeline steel during in-service welding. J Mater Sci 46:727–733
Lambert-Perlade A, Gourgues AF, Besson J et al (2004) Mechanisms and modeling of cleavage fracture in simulated heat-affected zone microstructures of a high-strength low alloy steel. Metall Mater Trans A 35:1039–1053
Ramachandran DC, Moon J, Lee C-H et al (2021) Role of bainitic microstructures with M-A constituent on the toughness of an HSLA steel for seismic resistant structural applications. Mater Sci Eng A 801:2–11
Sanz L, Pereda B, López B (2017) Effect of thermomechanical treatment and coiling temperature on the strengthening mechanisms of low carbon steels microalloyed with Nb. Mater Sci Eng A 685:377–390
Poorhaydari K, Patchett BM, Ivey DG (2006) Transformation twins in the weld HAZ of a low-carbon high-strength microalloyed steel. Mater Sci Eng A 435–436:371–382
Yang C, Luan Y, Li D et al (2019) Effects of rare earth elements on inclusions and impact toughness of high-carbon chromium bearing steel. J Mater Sci Technol 35:1298–1308
Chai F, Yang CF, Su H et al (2009) Effect of magnesium on inclusion formation in Ti-killed steels and microstructural evolution in welding induced coarse grained heat affected zone. J Iron Steel Res Int 16:69–74
Bonnevie E, Ferrière G, Ikhlef A et al (2004) Morphological aspects of martensite–austenite constituents in intercritical and coarse grain heat affected zones of structural steels. Mater Sci Eng A 385:352–358
Mohseni P, Solberg JK, Karlsen M et al (2013) Cleavage fracture initiation at M-A constituents in intercritically coarse-grained heat-affected zone of a HSLA steel. Metall Mater Trans A 45:384–394
Lambert A, Garat X, Sturel T et al (2000) Application of acoustic emission to the study of cleavage fracture mechanism in a HSLA steel. Scripta mater 43:161–166
Lambert-Perlade A, Gourgues AF, Pineau A (2004) Austenite to bainite phase transformation in the heat-affected zone of a high strength low alloy steel. Acta Mater 52:2337–2348
Chen L, Nie P, Qu Z et al (2020) Influence of heat input on the changes in the microstructure and fracture behavior of laser welded 800MPa grade high-strength low-alloy steel. J Manuf Process 50:132–141
Kim BC, Lee S, Kim NJ et al (1991) Microstructure and local brittle zone phenomena in high-strength low-alloy steel welds. Metall Mater Trans A 22:139–147
Gutiérrez I (2013) Effect of microstructure on the impact toughness of Nb-microalloyed steel: generalisation of existing relations from ferrite–pearlite to high strength microstructures. Mater Sci Eng A 571:57–67
Isasti N, Jorge-Badiola D, Taheri ML et al (2014) Microstructural features controlling mechanical properties in Nb-Mo microalloyed steels. Part I: Yield strength, Metall Mater Trans A 45:4960–4971
Funding
This work is strongly supported by the fundamental research funds for the central universities of China (No. N2007009) and the major industrial projects of science and technology plan of Liaoning Province, China (No. 2019JH1/10100014).
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Yulong Yang: conceptualization, methodology, formal analysis, writing—original draft, writing—review and editing, data curation. Xiao Jia, Yaxin Ma: investigation, validation, methodology, formal analysis. Ping Wang: methodology, validation, resources, supervision. Fuxian Zhu: methodology, funding acquisition, supervision, resources.
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Recommended for publication by Commission X - Structural Performances of Welded Joints - Fracture Avoidance
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Yang, Y., Jia, X., Ma, Y. et al. Microstructure and Impact Toughness of the Coarse-Grain HAZ Physically Simulated with Different Heat Inputs in a 690 MPa Ultra-low Carbon High-Strength Microalloyed Steel. Weld World 66, 1213–1227 (2022). https://doi.org/10.1007/s40194-022-01296-3
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DOI: https://doi.org/10.1007/s40194-022-01296-3