论文部分内容阅读
对电厂锅炉高温过热器管爆裂样管进行宏观形貌分析、化学成分分析、金相组织检验及力学性能检测。结果表明,钢的化学成分符合标准要求,室温力学性能强度满足标准要求而塑性低于标准要求;珠光体出现球化,在晶界处有聚集碳化物颗粒析出,晶界已形成微裂纹,爆口附近出现蠕变孔洞;烟气腐蚀冲刷减薄管壁,造成高温过热器管在弯头外侧的开裂。建议加强对高温过热器管金属工作温度的监测,同时采取合理的防磨措施,以减少烟气对高温过热器管外壁的腐蚀冲刷。
The macro-morphology analysis, chemical composition analysis, metallographic examination and mechanical property testing of high-temperature superheater tube burst pipes in power plant were carried out. The results show that the chemical composition of steel meets the standard requirements. The mechanical strength at room temperature meets the standard requirements and the plasticity is lower than the standard. Pearlitzite is spheroidized and aggregated carbide particles are precipitated at the grain boundaries. Microcracks are formed in the grain boundaries. Creeping holes appear near the mouth; flue gas erosion scour thinning the pipe wall, resulting in high temperature superheater tube cracking on the outside of the elbow. It is suggested to strengthen the monitoring of the metal working temperature of the high temperature superheater tube and adopt reasonable anti-wear measures to reduce the corrosion erosion of the outer wall of the high temperature superheater tube by the flue gas.