300M钢静态保温过程微观组织演化的原位分析

In-situ analysis on microstructure evolution of 300M steel during static holding process

采用热压缩与高温保温相结合的实验方法原位研究了不同工艺参数对300M钢静态保温过程微观组织演化的影响。结果表明,应变对静态保温过程晶粒尺寸的影响主要归因于微观组织演化的遗传继承关系,应变速率的影响主要归因于应变储存能的作用,保温温度的影响主要归因于静态再结晶机制的温度依赖性,而保温时间的影响主要归因于晶粒形核、吞并机制。基于工艺参数与静态保温过程晶粒尺寸演化的对应关系,提出了新的能够有效描述变形及静态保温参数影响的静态保温晶粒尺寸模型。研究为300M钢大型构件多道次热锻成形过程微观组织演化的准确预测及有效调控奠定了理论基础。

The effects of different processing parameters on microstructure evolution of 300M steel during the static holding process are studied in situ by combining hot compression and high-temperature holding experiments. Results show that the influence of strain on the average grain size evolution during the static holding process is mainly attributed to the hereditary of microstructures, the influence of strain rate is mainly attributed to strain storage energy, the influence of holding temperature is mainly attributed to the temperature dependence of static recrystallization, and the influence of holding time is mainly attributed to the mechanisms of grain nucleation and annexation. Based on the relationship between processing parameters and grain size evolution, a new grain size model is proposed, which can effectively describe the effects of deformation parameters and static holding parameters on grain size evolution. The above research provides a theoretical foundation for accurately predicting and effectively controlling microstructure evolution during the multi-pass hot forging of 300M steel heavy components.