亚温淬火对09MnNiDR容器钢板组织及断裂性能的影响

Effect of intercritical hardening on microstructure and fracture properties of 09MnNiDR vessel steel plate

利用光学显微镜、扫描电镜、热膨胀分析仪等对连铸-轧制方式生产的60 mm厚09MnNiDR容器钢板经不同亚温淬火+回火工艺处理后的组织和低温冲击性能进行了分析。结果表明:相比两次亚温淬火+回火工艺,采用淬火+亚温淬火+回火工艺的试验钢1/2厚度处冲击吸收能量大大提高,这与组织中小尺寸晶粒的占比提高有关;前者冲击断口形貌表现为准解理断裂,后者则为韧性断裂。

Microstructure and low temperature impact properties of the 09MnNiDR vessel steel plate with the thickness of 60 mm were analyzed by means of metallographic microscope,scanning electron microscope and thermosdilatometer.The results show that the impact absorbed energy at 1/2 thickness of the steel plate under quenching+intercritical hardening+tempering process is greatly improved comparing with that under twice intercritical hardening+tempering process,which is related to the increase of the proportion of small and medium-sized grains in the steel.The impact fracture morphology of the former process is quasi-cleavage fracture,while that of the latter process is ductile fracture.