Investigation on microstructure and impact toughness of double-pass laser-arc hybrid welding heat affected zone
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摘要: 采用焊接热模拟技术制备了低合金高强钢双道次激光电弧复合焊热影响区的均匀化组织试样，研究了二次峰值温度对热模拟试样微观组织和韧性的影响. 结果表明，未转变粗晶区为粗大的板条马氏体，晶粒尺寸在84 ~ 98 μm之间. 超临界再热粗晶区为细小的板条马氏体，晶粒尺寸为15.7 ~ 19.2 μm. 临界再热粗晶区为晶界和亚晶界分布有块状M-A组元的板条马氏体. 亚临界再热粗晶区组织为板条马氏体，晶粒尺寸在79 ~ 88 μm之间. 示波冲击试验结果表明，临界再热粗晶区试样抵抗裂纹形成能力最低，临界再热粗晶区和未转变粗晶区试样抵抗裂纹扩展能力最差.Abstract: Homogeneous specimens of the double-pass laser-arc hybrid welding heat affected zone (HAZ) of low alloy high strength steels were prepared by welding simulation technology, the influence of second peak temperature on the microstructure and toughness of the simulated specimens was investigated. The results showed that the unaltered coarse grained HAZ (UACGHAZ) compose of coarse lath martensite (LM) with an average grain size between 84 − 98 μm. The supercritically reheated CGHAZ (SCRCGHAZ) is comprised of fine LM with an average grain size between 15.7 − 19.2 μm. The intercritically reheated CGHAZ (ICCGHAZ) compose of LM with blocky martensite-austenite constituents distributed along grain boundaries and subgrain boundaries. The subcritically reheated CGHAZ (SRCGHAZ) is comprised of LM with an average grain size between 79 − 88 μm. The instrumented impact test results showed that the ICCGHAZ specimens own the lowest resistance to crack initiation, and the ICCGHAZ and UACGHAZ had the poorest resistance to crack propagation.
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图 2 试样1的微观组织
Figure 2. Microstructure of specimen 1. (a) optical microstructure; (b) scanning electron microstructure (low magnification); (c) scanning electron microstructure (high magnification)
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图 3 试样2的微观组织
Figure 3. Microstructure of specimen 2. (a) optical microstructure; (b) scanning electron microstructure (low magnification); (c) scanning electron microstructure (high magnification)
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图 4 ICCGHAZ试样的光学显微组织
Figure 4. Optical microstructures of ICCGHAZ specimens. (a) specimen 5 (nital); (b) specimen 4 (nital); (c) specimen 3 (nital); (d) specimen 5 (LePera); (e) specimen 4 (LePera); (f) specimen 3 (LePera)
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图 5 试样6的显微组织
Figure 5. Microstructures of specimen 6. (a) optical microstructure; (b) scanning electron microstructure
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图 6 不同二次峰值温度试样的示波冲击吸收功特征值
Figure 6. Instrumented impact energy parameters of different TM2 specimens
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图 7 试样1的断口形貌
Figure 7. Fracture surfaces of specimen 1. (a) crack initiation zone; (b) crack propagation zone
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图 8 试样2的断口形貌
Figure 8. Fracture surfaces of specimen 2. (a) crack initiation zone; (b) crack propagation zone
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图 9 不同二次峰值温度下ICCGHAZ试样的示波冲击吸收功
Figure 9. Instrumented impact energy of ICCGHAZ under different secondary peak temperature
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图 10 不同二次峰值温度下热模拟ICCGHAZ的裂纹扩展区断口形貌
Figure 10. Fracture surfaces of crack propagation zone of simulated ICCGHAZ specimens under different secondary peak temperature. (a) specimen 5; (b) specimen 4; (c) specimen 3
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图 12 Image-Pro Plus软件处理后的ICCGHAZ金相图
Figure 12. Metallograph images of ICCGHAZ after processing by Image-Pro Plus software. (a) specimen 5; (b) specimen 4; (c) specimen 3
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图 13 ICCGHAZ扫描电子显微镜组织图
Figure 13. Scanning electron microstructure images of ICCGHAZ. (a) specimen 5; (b) specimen 4; (c) specimen 3
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图 14 ICCGHAZ试样的EBSD表征
Figure 14. EBSD characterizations of ICCGHAZ specimens. (a) band contrast map of specimen 5; (b) band contrast map of specimen 4; (c) band contrast map of specimen 3; (d) euler map of specimen 5; (e) euler map of specimen 4; (f) euler map of specimen 3
表 1 EQ70钢的化学成分(质量分数，%)
Table 1 Chemical compositions of EQ70 steel
C Si Mn P Cu Cr Mo V N B Al Ni Fe 0.12 0.25 1.09 0.004 0.28 0.58 0.53 0.04 0.003 9 0.000 9 0.074 2.46 余量 
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表 2 焊接热模拟试样参数
Table 2 Welding simulation specimen parameters
试样编号 峰值温度TM /℃ 800 ℃冷却至500 ℃时间t8/5/s 单道次 二次 一次 二次 1 1 300 1 300 5 5 2 1 300 900 5 5 3 1 300 840 5 5 4 1 300 800 5 5 5 1 300 760 5 5 6 1 300 690 5 5
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表 3 示波冲击试验数据(J)
Table 3 Instrumented impact test results
试样编号 裂纹形成功Ei 裂纹稳定扩展功Ea 裂纹失稳扩展功Eb 撕裂功Ec 裂纹扩展功Ep 总冲击吸收功Et 1 24.3 0.7 0.8 4.2 5.7 30.0 2 23.8 2.9 0.7 9.7 16.2 40.0 3 20.2 1.6 1.0 11.2 13.8 34.0 4 19.6 0.8 1.4 7.2 9.4 29.0 5 14.6 0.4 0.8 4.9 6.1 20.7 6 22.9 3.1 1.0 14.0 18.1 41.0 CGHAZ 27.9 0.9 2.5 6.7 10.1 38.0 母材 35.9 51.0 4.7 21.6 77.3 113.2
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表 4 ICCGHAZ试样板条块亚结构宽度、M-A组元的体积分数和尺寸
Table 4 Block width, M-A constituent volume fraction and size of ICCGHAZ specimen
试样编号 板条块亚结构宽度
Wb /μm体积分数
A(%)M-A组元尺寸
SM-A/μm45°以上HAB比例
RHAB(%)5 19.3 2.9 2.5 12.6 4 21.7 3.2 2.1 13.9 3 12.5 0.9 1.8 16.3
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[1] Cao X, Wanjara P, Huang J, et al. Hybrid fiber laser–arc welding of thick section high strength low alloy steel[J]. Materials & Design, 2011, 32(6): 3399 − 3413.
[2] Kristensen J K. Thick plate CO2-laser based hybrid welding of structural steels[J]. Welding in the World, 2009, 53(1): 48 − 57.
[3] Bunaziv I, Akselsen O, Frostevarg J, et al. Laser-arc hybrid welding of thick HSLA steel[J]. Journal of Materials Processing Technology, 2018, 259: 75 − 87. doi: 10.1016/j.jmatprotec.2018.04.019
[4] Zhang S H, Shen Y F, Qiu H J. The technology and welding joint properties of hybrid laser-TIG welding on thick plate[J]. Optics Laser Technology, 2013, 48: 381 − 388. doi: 10.1016/j.optlastec.2012.11.014
[5] 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.
[6] Li X, Fan Y, Ma X, et al. Influence of Martensite-Austenite constituents formed at different intercritical temperatures on toughness[J]. Materials & Design, 2015, 67: 457 − 463.
[7] Li X, Ma X, Subramanian S V, et al. Structure-property-fracture mechanism correlation in heat-affected zone of X100 ferrite-bainite pipeline steel[J]. Metallurgical & Materials Transactions E, 2015, 2(1): 1 − 11.
[8] Bao Liangliang, Wang Yong, Han Tan. Microstructure and mechanical characterization of high strength low alloy steel welded joint by hybrid laser arc welding[C]//2019 the 7th International Conference on Mechanical Engineering, Materials Science and Civil Engineering, IOP Conference Series: Materials Science and Engineering. 2020, 758 : 012045.
[9] 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. doi: 10.12073/j.hjxb.20201207002 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. doi: 10.12073/j.hjxb.20201207002
[10] Han Tao, Zhang Hongjie, Wu Qian, et al. Numerical simulation of 80 ℃ temperature field distribution of thick plate multi-pass welding with SYSWELD[J]. China Welding, 2018, 21(7): 20 − 25.
[11] 王勇, 王引真, 张德勤. 材料冶金学与成型工艺[M]. 东营: 石油大学出版社, 2005. Wang Yong, Wang Yinzhen, Zhang Deqin. Materials metallurgy and processing[M]. Dongying: Petroleum University Press, 2005.
[12] Kim B C, Lee S, Kim N J, et al. Microstructure and local brittle zone phenomena in high-strength low-alloy steel welds[J]. Metallurgical Transactions A, 1991, 22: 139 − 149.
[13] Hamada M. Control of strength and toughness at the heat affected zone[J]. Welding International, 2003, 17(4): 265 − 270. doi: 10.1533/wint.2003.3100
[14] 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.
[15] 王振波, 何耀洋, 颜军, 等. 焊接钢榫卯连接装配式混凝土柱抗震性能分析[J]. 南京工业大学学报(自然科学版), 2022, 44(2): 187 − 197. Wang Zhenbo, He Yanyang, Yan Jun, et al. Seismic performance analysis of welded steel mortise and tenon joint assembled concrete columns[J]. Journal of Nanjing Tech University(Natural Science Edition), 2022, 44(2): 187 − 197.
[16] 伏玮, 马韩韩, 孔令瑞, 等. 氢对不同回火脆态下2.25Cr-1Mo-0.25V钢母材及焊缝韧脆转变温度的影响[J]. 南京工业大学学报(自然科学版), 2021, 43(6): 755 − 765. Fu Wei, Ma Hanhan, Kong Lingrui, et al. Effects of hydrogen on ductile-brittle transition temperature of 2.25Cr-1Mo-0.25V steel base metal and weld metal under different temper embrittlement states[J]. Journal of Nanjing Tech University(Natural Science Edition, 2021, 43(6): 755 − 765.
[17] 鲍亮亮, 潘春宇, 刘福建, 等. 低合金高强钢激光电弧复合焊热模拟热影响区组织与冲击韧性研究[J]. 焊接学报, 2022, 43(5): 90 − 97. Bao Liangliang, Pan Chunyu, Liu Fujian, et al. Research on the HAZ microstructures and toughness of the laser-arc hybrid welding of high strength low alloy steels[J]. Transactions of the China Welding Institution, 2022, 43(5): 90 − 97.
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