12Cr1MoV钢过热器爆管的显微组织和力学性能

Microstructure and Mechanical Properties of Burst Tube of Superheater of 12Cr1MoV Steel

以电站锅炉12Cr1MoV钢高温过热器爆管为研究对象,通过宏观观察、金相检验、硬度测试、化学成分分析等方法分析了爆管背烟侧及迎烟侧管材的显微组织及力学性能差异。结果表明:该过热器管材有明显劣化现象,爆管背烟侧和迎烟侧显微组织和力学性能存在明显差异;爆管迎烟侧组织老化现象较为严重,珠光体呈4.5级球化,常温拉伸性能和硬度明显低于背烟侧的,表明炉内长期高温烟气冲刷对高温过热器管迎烟侧材质劣化影响更为明显。

Burst tube of high temperature superheater of 12 Cr1 MoV steel in station boiler was studied.The difference of microstructure and mechanical properties between back and fire side of burst tube of superheater were analyzed by macroscopic obsewation,metallographic examination,hardness test and chemical composition analysis.The results show that the high temperature superheater tubes have obvious deterioration,and there were obvious differences in microstructure and mechanical properties between back and fire side of burst tube of superheater.The deterioration phenomenon of the pipe at the fire side was more serious,and the pearlite is 4.5 grade spheroidizing.The tensile and hardness indexes at room temperature are significantly lower than back side,indicating that the long term high temperature flue gas scour in the furnace has a more significant effect on the deterioration of the fire side to the high temperature superheater tube.