X38CrMo16模具钢模坯淬冷温度场仿真与参数选择

Temperature Field Simulation and Parameter Selection of X38CrMo16 Mould Steel Bloom During Quenching

X38CrMo16属于抗腐蚀性能优良的塑料模具钢，因导热性能较差和淬冷参数控制不当常常导致大件淬火开裂或心部未淬透现象发生。为解决这一问题，本文运用有限元法对尺寸为1700mm×280mm×650mm的X38CrMo16模块油淬温度场进行了仿真计算，并根据CCT曲线确定了模块油淬-空冷的转换时机．完成了模块淬冷参数的虚拟设计。结果表明，为减少淬火应力和避免心部珠光体组织转变，模块油中冷却时间控制在40-46min为宜．此时模块心部预测温度在576～665℃之间;按此淬冷工艺执行后，X38CrMo16模块淬火缺陷基本上得以消除，实现了淬冷过程的计算机预演。

The surface crack or the unhardened core often occur in a larger work-piece made from X38CrMo corrosion-proof plastic mould steel after quenching because of its lower thermal conductivity and unreasonable cooling time. In order to solve the problem, the simulation calculation of temperature field for 1700min×280mm×650mm X38CrMo mould steel bloom during quenching in oil were carried out using FEM, and the transition of oil quenching to air cooling was determined in accordance with CCT curve of X38CrMo steel. The simulation results reveal that the cooling time of X38CrMo mould steel bloom in oil is suggested to be controlled in the range of 40 to 46 min when the predicted temperature at core is about in the range of 576 to 665 ℃ to reduce quenching stress and to avoid the pearlite occurring at mould bloom core. The previous quenching defects in X38CrMo mould steel bloom were remove primarily since the simulated quenching parameter has been adopted, the preview and the virtual design of quenching process in computer were achieved.