38CrMoAl钢激光淬火研究  

Laser Surface Hardening for 38CrMoAl Steel

作　　者：王清波[1] 晁明举[1] 杨坤[1] 袁斌[1] 梁二军[1] 

机构地区：[1]郑州大学物理工程学院教育部材料物理重点实验室,河南郑州450052

出　　处：《金属热处理》2005年第2期81-83,共3页Heat Treatment of Metals

基　　金：河南省杰出人才创新基金 (0 12 10 0 12 0 0 );河南省高校青年骨干教师资助计划项目基金 (2 0 0 3 2 18)

摘　　要：利用连续波CO2 激光束 ,对 38CrMoAl钢进行了激光表面淬火研究 ,测量了淬硬层厚度和硬度分布 ,并对其金相组织进行了观察和分析。结果表明 ,38CrMoAl钢激光淬硬层的硬度可达 85 0HV0 3,是未淬火基体的 3～ 4倍。激光淬火层分为均匀相变区和过渡区 ,均匀相变区组织由均匀细化的位错马氏体 (包含少量残留奥氏体 )组成 ,过渡区为板条马氏体和未溶铁素体的混合组织。在激光功率和离焦量一定的条件下 ,硬化层厚度和宽度均随扫描速度增加而减小 ,而淬硬层硬度首先随扫描速度的增加而增加 ,达到一最大值时又呈下降的趋势。在离焦量4 8mm ,功率 1 8kW的条件下 ,38CrMoAl钢激光淬火的最佳扫描速度是 2 0mm/s。The laser surface hardening on 38CrMoAl steel was carried out using a continuous wave CO2 laser. The hardened depth and the hardness distribution in the cross-section of the hardened layer were tested and the microstructure in the hardened layer was observed and analyzed. The results show that the microhardness in the hardened layer reaches 850HV0.3,which is 3 [similar to] 4 times as high as that in the substrate. The hardened layer consists of two sub-layers including a uniform phase transformation layer and a transition layer. The corresponding microstructure in the uniform phase transformation layer is some fine dislocated lath martensite with a few retained austenite. The microstructure in transition layer is the mixture of lath martensite and undissolved ferrite. Under a proper laser power and a suitable off-focus length, both the hardened depth and width decrease with the increase of laser-scanning speed, but the hardness enhances firstly, decrease then with the increase of the laser scanning speed. The test shows that the optimal parameters for laser-hardening 38CrMoAl steel are of that the laser power is 1.8 kW, off-focus length is 48 mm, scanning speed is 20 mm/s.

关 键 词：激光淬火 38CRMOAL钢 显微组织 

分 类 号：TG156.99[金属学及工艺—热处理]