摘要
炼油厂加氢装置受到H2S腐蚀易引发安全事故。采用宏观检测、力学性能测试、金相显微分析、扫描电镜(SEM)观察、裂纹尖端及扩展部位的成分的电子能谱分析,对TP321钢制加氢反应加热炉炉管泄漏原因进行了分析。结果表明:焊接时连续快速加热使碳铬化合物沿晶界析出,导致焊缝晶界附近贫铬使其抗腐蚀性能下降,油气中含有较高浓度的H2S,从而在焊缝晶界处发生高温H2S腐蚀产生裂纹,裂纹在残余应力及其他外力的作用下以穿晶和沿晶混合模式扩展,最终导致炉管泄漏,设备失效。
Causes leading to leakage of the tubes made of TP321 stainless steel used in the heating furnace for hydroprocessing were explored based on macroinspection and mechanical property testing,as well as observation with metallurgical microscope and scanning electron microscope in association with elemental composition analysis at the crack tips and expanded zones by energy dispersive spectrometry.Results showed that intergranular chromium carbides were precipitated along the grain boundaries because of continuous and rapid heat treatment during welding,which led to decrease of intergranular corrosion resistance owing to Cr depletion in the regions adjacent to the grain boundaries.In the meantime,high concentration of hydrogen sulfide in the oil and gas caused high temperature H2S corrosion in the grain boundaries at the welded joints and resulted in cracks.Resultant cracks were propagated in transgranularintergranular mixed mode under residual stress and other external force.This eventually led to leakage of the furnace tube and failure of the hydroprocessing units.
出处
《材料保护》
CAS
CSCD
北大核心
2013年第2期63-65,69,共3页
Materials Protection
基金
国家自然科学基金(50971016
50901041)
中央高校基本科研业务费及专项资金(FRF-TP-09-029B)资助
关键词
管道泄漏
高温H2S腐蚀
裂纹
TP321钢
furnace tube leakage
high temperature H2S corrosion
cracks
TP321 stainless steel
