非调质钢亚动态再结晶分析及数学模型建立

Analysis on sub-dynamic recrystallization and establishment of mathematic model for non-quenched and tempered steel

根据18组热模拟试验及不同工艺参数的设计,获得TL1438非调质钢经过亚动态再结晶后的应力-应变曲线,比较了应变量、应变温度、应变速率、两次压缩后的保温时间对该过程的影响。采取理论与试验相互参照的方式,结合相关理论公式的推算,得出了两次压缩后的晶粒尺寸和动力学模型。结果显示:随着应变温度的增加,亚动态再结晶较易产生且速度较快,而应变速率的影响则相反,其中,两次压缩后的保温时间作用更加明显。通过物理试验及微观组织的研究,以达到预测非调质钢组织演变规律、优化工艺参数的目的,为今后分析此类锻件的综合力学性能和数值模拟提供参考。

According to the eighteen sets of thermal simulation tests and design of different process parameters,the stress-strain curve of TL1438 non-quenched and tempered steel was obtained after sub-dynamic recrystallization,and the influences of strain,strain temperature,strain rate and holding time after two times of compression on the process were compared.Combined with the calculation of related theoretical formulas,the grain size and kinetic model after two times of compression were obtained by the method of mutual reference between theory and test.The results show that as the strain temperature increases,the sub-dynamic recrystallization is easier to produce,and the generation speed is faster.But the effect of strain rate is reversed,and the effect of holding time after two times of compression is more obvious.Therefore,through physical experiments and microstructure research,the purpose of predicting the evolution law of nonquenched and tempered steel structure and optimizing process parameters is achieved,which provides a reference for the future analysis on the comprehensive mechanical properties and numerical simulation of this kind of this kind of forgings.