氧化皮对转子钢26Cr2Ni4MoV热物理参数的影响

Effect of surface oxide on thermo-physical parameters for 26Cr2Ni4MoV steel

大型锻件锻造过程中氧化皮是不可避免的,它影响着锻件表面的热交换过程,为向大型锻件锻造工艺的数值模拟提供符合生产实际的材料热物理参数,进行了转子钢26Cr2Ni4 MoV试件的高温加热和空冷试验,并通过反分析的方法测试出26Cr2Ni4 MoV在较厚氧化皮条件下的热物理参数。结果表明,氧化皮对转子钢26Cr2Ni4 MoV的热物理参数有很大影响,无氧化皮时黑度系数为0.64～0.76,有氧化皮时黑度系数为0.3;无氧化皮时锻件与模具间传热参数为1 N.s-1.mm-1.℃-1,有氧化皮时锻件与模具间导热系数为0.105 N.s-1.mm-1.℃-1。

Oxide which affects the heat exchange process of the surface for forgings is inevitable during forging process.In order to provide the thermophysical parameters which are consistent with the actual production for the numerical simulation of the forging process of large forgings,a set heating and cooling tests of rotor steel 26Cr2Ni4MoV were carried out and the equivalent thermophysical parameters of 26Cr2Ni4MoV under the influence of think oxide were obtained by anti-analysis.The results show that the oxide skin has important influence on the thermophysical parameters of 26Cr2Ni4MoV.In the case without surface oxide,the emissivity is from 0.64 to 0.76,and in the case with surface oxide,the emissivity is 0.3.In the case without surface oxide,the heat transfer coefficient between forging and die is 1 N·s-1·mm-1·℃-1,and in the case with surface oxide,the heat transfer coefficient between forging and die is 0.105 N·s-1·mm-1·℃-1.