【摘要】 激光交叠热处理45#钢在交叠区有较大的硬度下降，本文从热传导方程出发，分析了激光热处理过程中的温度场分布，由此讨论后一道处理对前一道硬化带的重新加热过程，以及不同温度区域所产生的不同程度回人或淬火而导致的不同硬度值变化，分析了实验现象并提出解决问题的方法。更多还原

【Abstract】 In the experiment of laser overlapping treating of 45 # steel, micro - hardness drops from HV820 to about HV400 in the overlapping region, This paper analyses the temperature field distribution during laser heat treatment according to heat conduction equation, and discusses repeating heat process between two courses of part of overlapping region. The regions of different temperature can produce different degree of tempering or quenching, and lead to different micro - hardness variation. Because there is existed a tempering process, we should decrease the overlapping region to increase the ratio of high - hardness zone on the surface of steel.更多还原