Effects of Heat Input on Microstructure and Mechanical Properties of Laser Welded 800 MPa Microalloyed Carbon Manganese Steel Joint
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摘要: 在不同热输入（1.27，1.52，1.90 kJ·cm-1）下对800 MPa级微合金化碳锰钢板进行了激光对接焊，研究了热输入对焊接接头显微组织、室温拉伸性能和-40℃冲击性能的影响。结果表明：热输入对焊接接头显微组织的影响很小，3种热输入下焊缝区和热影响区粗晶区的显微组织均为板条马氏体，热影响区细晶区的为细晶铁素体及其晶界处的马氏体-奥氏体（M-A）组元，混晶区的为尺寸不等的铁素体和M-A组元；随着热输入的增加，热影响区粗晶区的晶粒尺寸增大，细晶区的变化较小；热输入对焊接接头拉伸性能的影响很小，拉伸断裂位置均位于母材中；随着热输入的增加，焊缝区冲击功先增大后降低，当热输入为1.52 kJ·cm-1时达到最大，冲击断口都为韧性断口。Abstract: Laser butt welding was carried out on 800 MPa microalloyed carbon manganese steel plates under different heat inputs (1.27, 1.52, 1.90 kJ·cm-1), and then the effects of heat input on microstructure, room temperature tensile property and -40℃ impact property of the welded joints were studied. The results show that the heat input had little effect on microstructure of the welded joint. Under three heat inputs, the microstructures of the weld zone and coarse-grained heat affected zone consisted of lath martensite, that of the fine-grained heat affected zone was composed of fine grain ferrite and martensite-austenite (M-A) constituent at grain boundaries, and that of the mixed grain zone was composed of ferrite and M-A constituent with different size. With increasing heat input, the grain size of coarse-grained heat affected zone increased and that of the fine-grained zone changed little. The heat input had little effect on the tensile properties. All tensile fracture positions were located in base metal. With increasing heat input, the impact energy of the weld zone first increased and then decreased, and reached the maximum value when the heat input was 1.52 kJ·cm-1. The impact fracture exibited ductile fracture.
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Keywords:
- microalloyed steel plate /
- laser welding /
- microstructure /
- mechanical property
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[1] SHAO H, GOULD J, ALBRIGHT C. Laser blank welding high-strength steels[J]. Metallurgical & Materials Transactions B, 2007, 38(2):321-331.
[2] KANG M, KIM C. Laser welding for hot-stamped tailor-welded blanks with high-strength steel/high-energy absorption steel[J]. Journal of Laser Applications, 2014, 26(3):032007.
[3] 班孝东.高强汽车钢板焊接接头的组织与性能[J].金属热处理,2014,39(5):18-21. [4] 马文姝,王晓楠.高强C-Mn钢板复合焊接工艺与性能研究[J].铸造技术,2018,39(3):655-657. [5] WEI H L, BLECHER J J, PALMER T A, et al. Fusion zone microstructure and geometry in complete-joint-penetration laser-arc hybrid welding of low-alloy steel[J]. Welding Journal, 2015, 94(4):135-144.
[6] YANG J, LI Y L, ZHANG H. Microstructure and mechanical properties of pulsed laser welded Al/steel dissimilar joint[J]. Transactions of Nonferrous Metals Society of China, 2016, 26(4):994-1002.
[7] CASALINO G, CAMPANELLI S L, LUDOVICO A D. Laser-arc hybrid welding of wrought to selective laser molten stainless steel[J]. International Journal of Advanced Manufacturing Technology, 2013, 68(1/2/3/4):209-216.
[8] 张帅,侯丕吉,王娅菲.C-Mn钢板焊接工艺与性能研究[J].铸造技术,2018,39(2):418-421. [9] 余冬,罗志豪,王德威.焊接速度对Q420钢板激光焊接接头组织与力学性能的影响[J]. 热加工工艺,2018,47(1):231-235. [10] 汪水泽,甘晓龙,孙宜强,等.65Mn高碳钢板激光焊接接头热处理工艺研究[J]. 热加工工艺,2017,46(11):40-43. [11] 涂英明,景财年,范吉超,等.焊接速度对DP590双相钢板激光焊接接头组织和性能的影响[J].机械工程材料, 2016, 40(12):69-72.
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