LD冷作模具钢的激光相变强化研究  

Study on Laser Phase Transformation Hardening of LD Cold Work Die Steel

作　　者：杨超繁 张亚龙 冷星环 唐佳 王斌涛 YANG Chaofan;ZHANG Yalong;LENG Xinghuan;TANG Jia;WANG Bintao(Engineering Practice and Training Center,Shanghai University of Engineering Science,Shanghai 201620,China)

机构地区：[1]上海工程技术大学工程实训中心,上海201620

出　　处：《热加工工艺》2019年第24期94-97,共4页Hot Working Technology

基　　金：上海市科委地方院校能力建设项目(17030501400);上海市大学生创新项目(CS1724006).

摘　　要：研究了LD冷作模具钢经激光表面相变强化后的显微组织变化及其对材料性能的影响。结果表明:显微组织和力学性能呈规律性变化;强化区晶粒明显细化,出现排列致密的细针状马氏体和其他亚结构;硬度峰值一般出现在次表层,最高可达870 HV0.3以上,然后沿热量传递方向逐渐降低;强化层和基体之间存在热影响区,硬度明显下降,其平均硬度一般较基体降低15%以内。耐磨性和耐腐蚀性沿能量传输方向的变化与硬度变化规律保持一致。强化层厚度为0.5~0.8 mm,热影响区厚度基本在0.2 mm左右。强化层残余应力呈压应力,但在能量密度较高的情况下,试样产生熔融时最表层易产生拉应力。The microstructure change of LD cold work die steel after laser phase transformation hardening and its influence on the material properties were studied.The results show that the microstructure and mechanical properties change regularly.The grains in hardening layer are refined obviously.The fine acicular martensites which arrange compactly and other sub-structure appear.The hardness peak usually appears in the sub-surface,and the maximum value is up to 870 HV0.3 or more,then the hardness decreases gradually along the heat transfer direction.The heat affected layer zone appears in the region between the hardening layer and the substrate,and its hardness decreases obviously,and the average hardness is generally 15%lower than that of the substrate.The wear resistance and corrosion resistance changes along the direction of energy transfer as well as the hardness changing.The thickness of the hardening layer can is 0.5-0.8 mm,and the thickness of the heat-affected layer is about 0.2 mm.The residual stress of the hardening layer is compressive stress,but in the case of high energy density,the sample is melt,the surface is prone to generate tensile stress.

关 键 词：LD模具钢 激光相变硬化 显微组织 硬度 耐磨性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]