温度场的计算对淬火过程中热应力和热应变的分析有较大影响，对淬火后试件的残余应力和微观结构分析也有较大影响。本文以4ZCHMo钢圆柱体试件为研究对象，从相变等温动力学TTT图，给出了连续冷却相变动力学CCT图的数学模拟计算式，计算了钢淬火过程中相变组织成分百分比，将热物性系数处理为温度和相变体积百分比的函数，用有限单元法计算了淬火过程中具有非线性表面系数考虑相变时的温度场，并建立了相应的泛函，为以后计算淬火的热应力和热应变做好准备工作。

高压气体淬火技术是一种现代的、有效的材料加工技术。在Cheng所得到的高压气体淬火过程中非线性表面换热系数的基础上，用有限单元法对钢淬火过程的温度场与相变耦合问题进行了模拟计算。在数值计算中，材料的热物性系数被处理为温度和相变体积百分比的函数，为避免数值解的震荡，采用了Noraette有理近似法。

In numerical simulation of quenching process, the boundary conditions of temperature field and stress field are very important, in which the boundary conditions of temperature field are very complicated. In order to simulate the thermal strains, thermal stresses, residual stresses and microstructure of the steel during gas quenching by means of the numerical method, it is necessary to obtain an accurate boundary condition of temperature field. The surface heattransfer coefficient is a key parameter. The explicit finite difference method, non-linear estimate method and the experimental relation between temperature and time during quenching have been used to solve the inverse problem of heat conduction. The relationships between surface temperature and surface heat-transfer coefficient of cylinder have been given. The non-linear surface heat-transfer coefficients include the coupled effects between phase transformation and temperature. In calculation, physical properties were treated as the function of temperature and volume fraction of constituent. The results obtained have been shown that this technique can determine effectual the surface heat-transfer coefficients during gas quenching.

用实验和数值计算相结合的方法，得到半圆柱壳体快速冷却过程中内外表面的非线性表面换热系数。在此基础上，用有限单元法对半圆柱壳体的热应力和变形进行了分析。在数值计算中，模拟钢的CCT图，计算了奥氏体、珠光体、贝氏体和马氏体的体积百分比，并将热物理性质和力学性能处理为相变体积百分比和温度的函数。所得结果表明，在半圆柱壳体快速冷却过程中的热应力和变形计算中，有必要考虑非线性表面换热系数、相变等非线性效应。

温度场的计算对淬火过程中热应力和热应变的分析有较大影响，寸淬火后试件的残余应力和微观结构分析也有较大影响。本文以45钢圆柱试件为研究对象，采用文献[2]所得到的非线性表面换热系数，特Norsette法用于有限单元分析中，计算了淬火过程中的非线性温度场，有致地避免了在小时间步长下数值解出现震荡的问题。有限单元法数值解与实验结果吻合较好。