Hybrid laser arc welding of thick high-strength pipeline steels of grade X120 with adapted heat input
Hybrid laser arc welding of thick high-strength pipeline steels of grade X120 with adapted heat input
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DOI：
10.1016/j.jmatprotec.2019.116358
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发表时间：
2020-01-01
影响因子：
6.3
通讯作者：
Rethmeier, Michael
中科院分区：
文献类型：
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作者：
Ustundag, Omer;Gook, Sergej;Rethmeier, Michael
研究了热输入和焊接速度对20 mm厚X120高强度管线钢激光复合电弧单道焊组织和力学性能的影响。热输入在1.4 kJ mm（-1）至2.9 kJ mm（-1）的范围内变化，而焊接速度在0.5 m min（-1）至1.5 m min（-1）之间变化。采用一种基于外加振荡电磁场的熔池支撑新技术来补偿低速焊接时的静水压力。该技术的一个主要优点是，焊接速度和冷却时间t（8/5）可以在宽的参数窗口内变化，而不会出现焊缝根部质量问题。该方法可满足X120管线钢的焊接热循环要求。所有受试Charpy-V试样均符合API 5 L关于冲击能量的要求。对于较高的热输入，在-40 ℃的测试温度下，平均冲击能量为144 +/-37 J。高于1.6 kJ mm（-1）的高热输入导致焊缝金属和热影响区软化，从而导致强度损失。在1.4 kJ mm（-1）~ 1.6 kJ mm（-1）的热输入下，最低拉伸强度可达915 MPa。
The influence of heat input and welding speed on the microstructure and mechanical properties of single-pass hybrid laser arc welded 20 mm thick plates of high-strength pipeline steel X120 were presented. The heat input was varied in the range of 1.4 kJ mm(-1) to 2.9 kJ mm(-1), while the welding speed was changed between 0.5 m min(-1) and 1.5 m min(-1). A novel technique of bath support based on external oscillating electromagnetic field was used to compensate the hydrostatic pressure at low welding velocities. A major advantage of this technology is, that the welding speed and thus the cooling time t(8/5) can be variated in a wide parameter window without issues regarding the weld root quality. The recommended welding thermal cycles for the pipeline steel X120 can be met by that way. All tested Charpy-V specimens meet the requirements of API 5 L regarding the impact energy. For higher heat inputs the average impact energy was 144 +/- 37 J at a testing temperature of - 40 degrees C. High heat input above 1.6 kJ mm(-1) leads to softening in the weld metal and heat-affected-zone resulting in loss of strength. The minimum tensile strength of 915 MPa could be achieved at heat inputs between 1.4 kJ mm(-1) and 1.6 kJ mm(-1).