激光辐照对渗硼后65Mn钢组织和性能的影响

Effects of laser irradiation on microstructure and properties of boronized 65Mn steel

采用激光辐照对渗硼后65Mn钢进行了表面改性,研究了激光重熔和激光淬火两种典型辐照处理后的微观组织、表层脆性和耐磨性。结果表明:65Mn钢渗硼试样,经激光重熔后其表层组织为夹杂着共晶硼化物的亚共晶组织(硬度约为880 HV),而经激光淬火后其表层组织是以Fe2B相为主的硼化物(硬度约为1100 HV),两种辐照处理后在次表层均形成了具有良好支撑作用的针状马氏体区;同时,两种激光辐照处理对表层脆性均有着较好的改善作用,脆性等级由原渗硼层的4级降低至1~2级;此外,经激光淬火后65Mn钢渗硼试样的耐磨性,不仅远好于激光重熔处理后的试样,而且也好于激光辐照处理前的渗硼试样。

Surface modification of boronized 65Mn steel was carried out by using laser irradiation technology. Microstructure,surface brittleness and wear resistance of the boronized 65Mn steel after different laser irradiation processes which were laser remelting and laser quenching were investigated. Results show that the surface microstructure of boronized 65Mn steel after laser remelting exhibits hypoeutectic steel microstructure mixed with eutectic boride,for which hardness is about 880 HV. The microstructure after laser quenching is boride mainly composed of Fe2B with hardness about 1100 HV. Meanwhile,there is an acicular martensite zone possessing of good support effect to the boronized layer in their subsurface after the laser irradiation. Both the laser remelting and the laser quenching significantly improve the boronized layer surface brittleness,whose brittleness decreases from grade 4 to grade 1 to 2. Furthermore,the wear resistance of the boronized 65Mn steel after laser quenching,is not only far better than the one after laser remelting,but also better than that one before laser irradiation.