摘要
对 4 0铬钢进行表面加碳激光合金化处理 ,得到深 0 .2 5～ 0 .35mm的白口铸铁层 ,白口铸铁层组织呈梯度变化 ,晶粒明显细化 ,显微硬度高达 12 0 0HV0 .3 以上。热影响相变区组织为马氏体 ,并存在有针状马氏体到隐晶马氏体的分层 ,硬度为 710～ 780HV0 .3 ,比常规淬火明显提高。采用高的激光密度、快的扫描速度 ,有助于晶粒的细化 ,从而使硬度提高。磨损实验表明 ,白口铁层的磨损性能比常规淬火样品提高约 5 0 %。
The 40Cr steel has been surface alloyed with a pre deposited carbon powder layer by laser beam.White cast iron is obtained on the surface of the sample with a depth of 0.25～0.35mm.The microstructure of the melted zone is pre dendrite and eutectic ledeburite whose size is obviously refined by the rapid quench.Its micro hardness can get up to 1200HV 0.3 .The microstructure of the heat affected zone is martensite with two sub layers,one of which is pin like martensite and the other,no pin martensite.It indicates that the higher the scanning speed and power density,the smaller the grain,and therefore the higher the micro hardness.The wear test shows that the wear resistance of the specimens has been encreased by 50% than the general quenched samples.
出处
《激光技术》
CAS
CSCD
北大核心
2002年第1期1-3,8,共4页
Laser Technology
基金
国家教委回国留学人员基金
原有色总公司回国留学人员基金资助项目
