通过建立高强化柴油机气门座激光相变硬化温度场的数值模拟模型,分析了激光相变硬化过程中工艺参数对气门座温度场的影响。结果表明,随着激光功率的增大,气门座相变硬化的峰值温度升高,温度场呈拖尾的彗星状,硬化层的深度和宽度增大;随着扫描速度的增大,气门座相变硬化的峰值温度降低,温度场拖尾的彗星形状减小,硬化层的深度和宽度减小;随着光斑半径的增大,气门座相变硬化的峰值温度降低且位置发生偏移,温度场拖尾的彗星形状增大,硬化层的深度减小。

A numerical simulation model of the temperature field in the laser phase-transformation hardening of the highly-enhanced diesel engine valve seats is established and the influences of different process parameters on this temperature field are investigated in the laser phase-transformation hardening process. The results show that, with the increase of the laser power, the peak temperature of the phase-transformation hardening of the valve seats increases, the temperature field presents a cometary shape with a tail, and the depth and the width of the hardened layer increase synchronously. In contrast, with the increase of the scanning speed, the peak temperature of the phase-transformation hardening of the valve seats decreases, the cometary tail of the temperature field gets smaller, and the depth and the width of the hardened layer decrease synchronously. Moreover, with the increase of the laser spot radius, the peak temperature of the phase-transformation hardening of the valve seats decreases and its corresponding position shifts, the cometary tail of the temperature field gets larger, the depth of the hardened layer decreases.