摘要
为判别炉管的损伤程度和运行安全性,本文对运行了约46 000 h的苯乙烯生产加热炉炉管,在大修期间进行了宏观检查、氧化物的XRD(X-ray d iffraction)分析、管径测量、超声波测厚、硬度试验、金相组织分析及炉管的危险点计算分析等。实验结果表明:炉管表面发生了高温氧化以及碳化腐蚀,炉管壁厚明显减薄。与新管相比硬度也明显下降,显微组织明显退化,骨架状共晶碳化物形态消失,一次碳化物和从奥氏体晶内析出的二次碳化物明显粗化,且析出少量块状σ相。并在此基础上对炉管的剩余使用寿命作了估算。
Overheat steam heating tubes after servicing 46 000 h for distinguishing the damnification degree are analyzed, by visual inspection, X-ray diffraction （XRD） analysis of the oxide, measurement of the wall thickness and diameter, hardness-measuring, optical metallographic examination and the danger point analysis. Experimental result shows that the corrosive mechanism of surface materials produces the oxidation and carbonization corrosion. And the thickness and the hardness of the boiler pipe are descended compared with the new pipe. By the optical microscope it is seen that conformation of the framework eutectic carbide is disappeared, the first and the second carbides precipitated in austenite are coarsened, and a spot of σ phase is precipitated. On this base, the residual life of the boiler pipe is estimated.
出处
《南京航空航天大学学报》
EI
CAS
CSCD
北大核心
2005年第5期616-620,共5页
Journal of Nanjing University of Aeronautics & Astronautics
