摘要
使用光纤激光对碳质量分数为0.28%,碳当量为0.7的TRIP钢进行焊接。通过对激光焊接接头显微硬度、拉伸性能及显微组织进行测试和表征,研究了线能量对TRIP钢焊接接头显微组织和力学性能的影响。结果表明,线能量在43.75 J/mm至30.55 J/mm之间进行变化对焊缝的平均显微硬度影响不明显;焊接样品抗拉强度与母材强度接近,随着线能量的降低,焊接样品塑性损失逐渐降低;激光焊接形成的焊缝由板条马氏体及下贝氏体组成,焊缝的显微组织形貌及组成相类型随线能量的变化未发生显著改变;线能量可影响热影响区的温度梯度,使热影响区显微组织的空间分布发生改变。
The TRIP steel with 0. 28% carbon（ by mass） and 0. 7 carbon equivalent was welded by fiber laser. The effect of heat input per unit length on microstructure and mechanical properties of welded joints were investigated through testing and characterization of micro-hardness,tensile properties and microstructure of laser welded joints. The results showed that with the decrease of heat input per unit length from 43. 75 J/mm to 30. 55 J/mm,the hardness of the fusion zone（ FZ）was nearly unvaried,the tensile strength of the welded samples was close to the strength of base metal,and the loss of ductility decreased gradually. The microstructure of FZ was mainly composed of lath martensite and lower bainite,which varied little with the heat input per unit length. The spatial distribution of HAZ microstructure could be influenced by the heat input per unit length due to the significant temperature gradient over the narrow HAZ.
出处
《上海金属》
CAS
北大核心
2017年第5期51-56,共6页
Shanghai Metals
基金
国家重点基础研究发展计划项目(2010CB630802)
关键词
激光焊接
TRIP钢
线能量
焊接接头
显微组织
力学性能
laser welding, TRIP steel, heat input per unit length, welded joint, microstructure, mechanical property
