2.25Cr1Mo钢大型筒体锻件差温热处理过程研究

Research on Differential Temperature Heat Treatment Process for 2.25Cr1Mo Steel Heavy Cylindric Forging

通过在差温炉中的加热试验和有限元模拟,研究了2.25Cr1Mo钢大型筒体锻件热处理加热过程的温度场,计算了筒体在热处理过程中的温度变化;采用逆算法确定了筒体加热过程预热段和高速升温段的综合界面换热系数。综合界面换热系数由对流换热系数、辐射换热系数和修正换热系数三部分组成。在高速升温段,由于局部炉气分布不均匀,修正换热系数较大;而在预热和保温段,计算所得的修正换热系数较小。运用修正的换热系数计算的筒体的外表面温度与实际测量温度相差±13℃。预测结果表明,所编制的软件程序与实际升温曲线符合很好,为今后预测大型锻件差温热处理过程的温度场提供了依据。

Through experiments of differential temperature heat treatment and finite element simulation,the transient temperature field of 2.25Crl Mo steel heavy cylindrical forging was obtained and the interface heat-transfer coefficient was ealeulated by inverse heat eonduetion method. The eomprehensive interfaee heat-transfer eoeffieient eonsists of eonveetional heat transfer eoeffieient,radiate heat transfer eoeffieient and eorrected heat transfer eoeffieient. The eorreeted heat transfer eoeffieient is large in the high-speed heating proeess due to the loeal an uneven furnaee atmosphere distribution, and is small in the preheating and holding period. The differenee between the outer surfaee temperature of the eylinder ealeulates with the eorrected eoeffieient and the determined temperature is ＋ 13℃. The predieted results show that the software program coineides with the practieal ramp curve,providing a good referenee for predieting the temperature field of large forging parts.