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用500W的CO_2激光束扫描两种常用材料45钢及T10A,功率密度为1.3～1.5×10~4W/cm~2,在8～18mm/s的扫描速度下可得0.2～0.4mm的硬化层。表面硬度可达HV800以上,显著高于普通淬火。分析表明这是组织细化及亚结构因素所致。硬化层的分层情况受多种因素影响,原始状态越不均匀分层越多。45钢可分成四层:细针状马氏体(M),细针马氏体及隐针马氏体,细针M隐针M及未溶的破碎状铁素体,隐针M及铁素体网络。激光相变硬化层具有某些微观特征,比如奥氏体细晶粒、45钢中出现不同碳浓度的马氏体区以及狭窄的过渡层等等,均是急速相变的直接结果。
Two common materials, 45 steel and T10A, were scanned with a 500 W CO 2 laser beam with a power density of 1.3 to 1.5 × 10 4 W / cm 2 and a hardened layer of 0.2 to 0.4 mm at a scanning speed of 8 to 18 mm / s . Surface hardness up to HV800, significantly higher than the ordinary quenching. The analysis shows that this is caused by the refinement and sub-structure of the organization. The layering of the hardened layer is affected by a number of factors, the more uneven the original state is, the more layers are layered. 45 steel can be divided into four layers: fine needle-like martensite (M), fine needle martensite and hidden needle martensite, fine needle M hidden needle M and undissolved crushed ferrite, hidden needle M and iron Element network. The laser phase-change hardened layer has some microscopic features, such as austenite grain size, martensitic region with different carbon concentration in 45 steel, narrow transition layer and so on, which are the direct results of rapid phase transformation.