摘要
为了探究QP980高强钢激光焊接热循环过程微观组织演变机理,通过材料的合金成分,用JMatPro软件计算QP980高强钢的高温热物理性能,将这些参数代入Sysweld软件模拟了试件温度场的分布,通过仿真结果与实验结果对比验证该模型的准确性。并结合焊接热循环过程的冶金相变等理论知识,分析了QP980高强钢激光焊接接头在焊接热循环作用下的微观组织演变的机理。结果表明:在焊接过程中焊缝中心的铁素体迅速奥氏体化,冷却后焊缝中心的铁素体和残余奥氏体的相体积分数分别由初始状态的51.9%、10.6%全部转变成马氏体组织,马氏体则由初始状态的37.5%增加到接近100%;而亚临界热影响区的热循环峰值温度低于Ac1,产生回火马氏体导致接头软化。
To explore the microstructure evolution mechanism of QP980 high strength steel during the laser welding thermal cycle,this paper uses the alloy composition of the material to calculate the high-temperature thermophysical properties of QP980 high-strength steel with JMatPro software and substitutes these parameters into the Sysweld software to simulate the temperature field distribution of the specimen.The accuracy of the model is verified by comparing simulation results with experimental results.And combined with theoretical knowledge of metallurgical phase transition during the welding thermal cycle,the mechanism of microstructure evolution of QP980 high-strength steel laser welded joint under the welding thermal cycle is analyzed.The results show that the ferrite in the center of the weld is rapidly austenitized during the welding process,after cooling,the phase volume fractions of ferrite and retained austenite in the center of the weld are all transformed into martensite from 51.9%and 10.6%of the initial state,respectively.The martensite increased from 37.5%in the initial state to nearly 100%;the peak temperature of the thermal cycle in the subcritical heat-affected zone was lower than Ac1,resulting in tempered martensite and softening of the joint.
作者
宋涛
张大斌
曹阳
陈素
陈大江
文梦蝶
SONG Tao;ZHANG Da-bin;CAO Yang;CHEN Su;CHEN Da-jiang;WEN Meng-die(School of Mechanical Engineering,Guizhou University,Guiyang 550025,China)
出处
《组合机床与自动化加工技术》
北大核心
2021年第12期117-120,共4页
Modular Machine Tool & Automatic Manufacturing Technique
基金
贵州省科技计划项目(黔科合平台人才[2019]5616号)。
关键词
QP980高强钢
激光焊接
温度场
热循环
组织演变
QP980 high strength steel
laser welding
temperature field
thermal cycle
microstructure evolution
