Effect of welding speed on microstructure and mechanical properties of laser-welded transformation induced plasticity (TRIP) steels
Tao Wang1, Mei Zhang2,3, Ren‑dong Liu4, Liang Zhang1, Lin Lu1, Wen‑heng Wu1
1 Shanghai Research Institute of Materials, Shanghai Engineering Research Center of 3D Printing Materials, Shanghai 200437, China 2 School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China 3 State Key Laboratory of Advanced Special Steels, Shanghai University, Shanghai 200072, China 4 Technique Center of Ansteel, Ansteel Group Corporation, Anshan 114001, Liaoning, China
Effect of welding speed on microstructure and mechanical properties of laser-welded transformation induced plasticity (TRIP) steels
Tao Wang1, Mei Zhang2,3, Ren‑dong Liu4, Liang Zhang1, Lin Lu1, Wen‑heng Wu1
1 Shanghai Research Institute of Materials, Shanghai Engineering Research Center of 3D Printing Materials, Shanghai 200437, China 2 School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China 3 State Key Laboratory of Advanced Special Steels, Shanghai University, Shanghai 200072, China 4 Technique Center of Ansteel, Ansteel Group Corporation, Anshan 114001, Liaoning, China
摘要 The weldability of 0.28C–2.0Mn–0.93Al–0.97Si (wt.%) transformation induced plasticity (TRIP) steels was investigated using a 2.5 kW CO2 laser at the welding speeds of 2, 2.5 and 3 m/min. The welded joints were characterized in terms of hardness, tensile properties and microstructure. High-quality welded joints of TRIP steels with the carbon equivalent of 0.7 were obtained. Lower loss of ductility, nearly unvaried hardness of the fusion zone (FZ) and tensile strength equal to the base metal were observed with increasing welding speed. Lath martensite and lower bainite formed in FZ and the microstructure of FZ varied little with welding speed. Weld thermal simulations of heat-afected zone (HAZ) were carried out using a quenching dilatometer, and the microstructures of dilatometric samples revealed the carbon diffusion-controlled transformations in HAZ. The microstructure distribution of HAZ could be influenced by the welding speed due to the significant temperature gradient over the narrow HAZ.
Abstract：The weldability of 0.28C–2.0Mn–0.93Al–0.97Si (wt.%) transformation induced plasticity (TRIP) steels was investigated using a 2.5 kW CO2 laser at the welding speeds of 2, 2.5 and 3 m/min. The welded joints were characterized in terms of hardness, tensile properties and microstructure. High-quality welded joints of TRIP steels with the carbon equivalent of 0.7 were obtained. Lower loss of ductility, nearly unvaried hardness of the fusion zone (FZ) and tensile strength equal to the base metal were observed with increasing welding speed. Lath martensite and lower bainite formed in FZ and the microstructure of FZ varied little with welding speed. Weld thermal simulations of heat-afected zone (HAZ) were carried out using a quenching dilatometer, and the microstructures of dilatometric samples revealed the carbon diffusion-controlled transformations in HAZ. The microstructure distribution of HAZ could be influenced by the welding speed due to the significant temperature gradient over the narrow HAZ.
Tao Wang,Mei Zhang,Ren‑dong Liu, et al. Effect of welding speed on microstructure and mechanical properties of laser-welded transformation induced plasticity (TRIP) steels[J]. Journal of Iron and Steel Research International, 2020, 27(9): 1087-1098.
2020, Vol. 27 
