Sun Chaoyuan, Qin Yi, Liu Yang, Xiao Guiqian, Zhang Jiansheng, Zhou Jie
Chongqing Key Laboratory of Advanced Mold Intelligent Manufacturing, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
China National Erzhong Group Deyang Wanhang Die Forging Co., Ltd., Deyang 618013, China.
Materials (Basel). 2024 Feb 21;17(5):991. doi: 10.3390/ma17050991.
To obtain the optimal hot deformation process, the rheological and dynamic recrystallization behaviors of A100 steel were researched through isothermal compression tests. Firstly, a Hensel-Spittel constitutive model was established based on the stress-strain curves. Secondly, dynamic recrystallization percentage and grain size models were established to identify the necessary conditions for complete dynamic recrystallization. Finally, microstructural analysis was employed to validate the accuracy of the recrystallization model. The results indicate that the flow stress is highly sensitive to both the strain rate and the temperature, and the HS model demonstrates a high predictive accuracy, with a correlation coefficient of 0.9914. There exists a contradictory relationship between decreasing the average grain size and increasing the recrystallization percentage. The higher the percentage of dynamic recrystallization, the larger the average grain size tends to be. This situation should be avoided when devising the actual processing procedures. The optimal hot working processes for achieving complete dynamic recrystallization and a smaller average grain size are as follows: a strain equal to or greater than 0.6, a temperature between 1193 and 1353 K, and a strain rate between 0.1 and 1 s.
为获得最佳热变形工艺,通过等温压缩试验研究了A100钢的流变行为和动态再结晶行为。首先,基于应力-应变曲线建立了Hensel-Spittel本构模型。其次,建立了动态再结晶百分数和晶粒尺寸模型,以确定完全动态再结晶的必要条件。最后,采用微观组织分析来验证再结晶模型的准确性。结果表明,流变应力对应变速率和温度都高度敏感,HS模型具有较高的预测精度,相关系数为0.9914。平均晶粒尺寸减小与再结晶百分数增加之间存在矛盾关系。动态再结晶百分数越高,平均晶粒尺寸往往越大。在设计实际加工工艺时应避免这种情况。实现完全动态再结晶和较小平均晶粒尺寸的最佳热加工工艺如下:应变等于或大于0.6,温度在1193至1353 K之间,应变速率在0.1至1 s之间。