摘要
从理论上分析了简易激光相变硬化模型估算激光淬火硬化带深度的不合理之处,即将硬化带深度确定在珠光体向奥氏体转变的临界温度θAC1等温线处;在该深度处C原子并未充分扩散,也就是说该深度处材料并未有效硬化。在此基础上,提出一种新的估算硬化带深度的模型--△t模型,其原理为将Fourier热传导理论和保证C原子充分扩散的时间段△t相结合,估算相变硬化带尺寸。最后,采用新模型估算出激光淬火处理HT250材料硬化带深度的理论值,理论估算结果与试验结果吻合较好,且比简易激光相变硬化模型估算结果更接近于试验结果。
It is theoretically analyzed the invalidity of the simple model for evaluating the hardened depth obtained through laser quench, in which the isothermal line of critical temperature for perlite changing into autensite is taken as the hardened depth. However at the critical temperature isothermal line, C atoms can't diffuse adequately and then material there can't be effectively hardened accordingly. Based on the said theoretical analysis, a new model(△t model) is proposed. In the new model, Fourier thermal conductivity theory and time space △t, ensuring the adequate diffusion of C atoms, are used to evaluate the dimensions of the hardened zones. The new model has been used to evaluate the hardened depth of laser-quenched HT250, and the theoretical results are verified by the experiments and are more accurate than that of the old model.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2005年第5期196-199,204,共5页
Journal of Mechanical Engineering
关键词
激光淬火
硬化带
数值计算
马氏体
Laser quenching Hardened zone Numerical analysis Martensite
