激光熔覆Fe基合金涂层强化H13热作模具钢  

Laser cladding Fe-based alloy coating for strengthening H13 hot work die steel

作　　者：姜高强 崔承云[1] 魏礼桢 崔熙贵[1] JIANG Gaoqiang;CUI Chengyun;WEI Lizhen;CUI Xigui(School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学机械工程学院,江苏镇江212013

出　　处：《材料科学与工艺》2022年第2期35-42,共8页Materials Science and Technology

基　　金：国家自然科学基金资助项目(51875267,51505198);江苏大学工业中心大学生创新实践基金资助项目(ZXJG2021035)。

摘　　要：为了解决H13热作模具钢在锻模和热挤压模等领域因发生脱模剂腐蚀而失效的问题,本文通过引入激光熔覆技术来探究Fe基合金粉末对H13钢综合性能的强化效果,并系统研究了扫描速度、搭接率和熔覆层数对涂层的相位组成和显微组织的影响,详细分析了涂层的截面显微硬度和耐腐蚀性能的变化规律。研究表明:涂层主要由α-Fe、γ-Fe、M_(23)C_(6)和M_(7)C_(3)相组成;高的扫描速度下γ-Fe来不及完全转化为α-Fe,但高搭接率的延迟凝固作用促进了γ-Fe的转化;第2涂层减弱的衍射峰是由于少量基体元素的扩散而导致碳化物减少;涂层中主要合金元素Fe与Cr、Si、Mo、C分别在晶粒和晶界中交替增减,归因于Cr、Si、Mo和C等元素向晶界处沉积。相较于基体,涂层的硬度明显提升,提升率分别为197.7%、204.5%、68.2%和145.5%。高的扫描速度对耐腐蚀性影响较小,高的搭接率和多层熔覆对耐腐蚀行为有积极意义。To solve the problem of H13 hot work die steel failure caused by the corrosion of mold release agent during forging and hot extrusion processes,laser cladding was introduced to investigate the comprehensive performance of Fe-based alloy powders for strengthening H13 steel.The effects of scanning speed,overlap rate,and the number of layers on the phase composition and microstructure of coating were studied,and the changes in the microhardness and corrosion resistance of coating were analyzed.Results showed that the coating was mainly composed ofα-Fe,γ-Fe,M_(23)C_(6),and M_(7)C_(3).At high scanning speed,γ-Fe could not be completely converted intoα-Fe,but the delayed solidification effect of high overlap rate promoted the conversion ofγ-Fe.The weakened diffraction peaks of the second coating layer were due to the diffusion of a small number of matrix elements,leading to the reduction of carbides.The main alloy elements Fe and Cr,Si,Mo,C alternately increased and decreased in the grains and grain boundaries,attributed to the deposition of Cr,Si,Mo,and C to grain boundaries.Compared to the substrate,the microhardness of the coatings were obviously improved,and the improvement rates were 197.7%,204.5%,68.2%,and 145.5%.High scanning speed had less impact on the corrosion resistance behavior,while high overlap rate and multi-layer cladding had positive significance.

关 键 词：激光熔覆 Fe基 H13钢 显微组织 显微硬度 耐腐蚀性 

分 类 号：TN249[电子电信—物理电子学]