二次热循环对09MnNiDR钢粗晶区组织和韧性的影响

Effect of Secondary Thermal Cycle on the Microstructure and Toughness of Coarse Grain Zone in 09MnNiDR Steel

利用MMS-300热力模拟机对09MnNiDR钢进行二次热循环模拟试验,并结合显微组织分析技术和冲击试验对粗晶区组织进行了观察。研究结果表明,经历二次热循环后,09MnNiDR钢粗晶区显微组织发生阶段性变化,二次热循环对一次热循环粗晶区冲击吸收能量并不都具有改善作用,峰值温度为900℃的二次热循环明显改善冲击吸收能量的原因在于原晶界处M-A组元的消失和针状铁素体的形成,而其他峰值温度二次热循环不能明显改善冲击吸收能量的原因归结于M-A组元的形成和晶粒粗大。

The MMS-300 thermal simulator was used to carry out the secondary thermal cycle simulation test on 09MnNiDR steel,and the MMS-300 thermal simulator was used to carry out the secondary thermal cycle simulation test on 09MnNiDR steel,and the microstructure of coarse grain zone was observed by combining the microstructure analysis technology and impact test.The results show that the microstructure of the coarse-grained zone of 09MnNiDR steel changes in stages after the second thermal cycle.The second thermal cycle does not improve the impact absorption energy of the coarse-grained zone of thefirst thermal cycle.The reason why the second thermal cycle with a peak temperature of 900℃obviously improves the impact absorption energy is the disappearance of the M-A component at the grain boundary and the formation of acicular ferrite;The reason why the secondary thermal cycle at other peak temperatures can not significantly improve the impact absorption energy is attributed to the formation of M-A component and the coarse grain size.