激光热处理对7CrSiMnMoV模具钢组织与性能的影响

Influence of laser heat treatment on microstructure and properties for 7CrSiMnMoV die steel

激光热处理是一种高效、清洁的表面强化工艺,以7CrSiMnMoV模具钢为研究对象,进行了不同工艺参数下的激光热处理工艺实验,研究了激光功率和激光扫描速度对淬硬层微观组织和性能的影响规律。结果表明:7CrSiMnMoV模具钢自表层至淬硬层和热影响层均产生了大量针状马氏体,马氏体含量及其晶粒尺寸均随层深的增加而减小。通过控制激光能量密度即可使材料获得一定深度的淬硬层,拟合得到了淬硬层深度与激光能量密度的关系式,实现了淬硬层深度的预测。通过室温摩擦磨损实验,发现淬后试样的耐磨性显著增强,且试样的耐磨性随激光能量密度的增大而提升。

Laser heat treatment is an efficient and clean surface strengthening process.For 7CrSiMnMoV die steel,laser heat treatment process experiments with different process parameters were conducted,and the influence laws of laser power and laser scanning speed on the microstructure and properties of hardened layer were studied.The results show that a large amount of acicular martensite is produced in 7CrSiMnMoV die steel from the surface layer to the hardened layer and the heat-affected layer,and the martensite content and its grain size decreases with the increasing of layer depth.By controlling the laser energy density,the material can obtain a hardened layer with a certain depth,and the relation formulas between hardened layer depth and laser energy density is obtained by fiting to realize the prediction of the hardened layer depth.Through room temperature friction and wear experiments,it is found that the wear resistance of quenched sample is significantly enhanced,and the wear resistance of sample improves with the increasing of laser energy density.