电站锅炉主蒸汽管弯头错用碳钢失效分析

Failure Analysis of Carbon Steel Misused in Main Steam Pipe Elbow of Utility Boiler

为避免锅炉事故发生,确保锅炉安全运行,指明电站锅炉主蒸汽管道正确选材的重要性,通过对某化纤厂自备电站锅炉主蒸汽管弯头错用碳钢发生断裂泄漏事故进行分析,结合事故周边正确用材弯头和直段管道,利用宏观检验、壁厚测定、光谱分析、金相组织分析、强度校核、表面无损检测等检验检测方法,分析锅炉主蒸汽管弯头错用碳钢长期超温运行后金属的组织变化情况,分析指出严重超温运行会导致碳钢主蒸汽管弯头金属组织发生严重珠光体球化、严重石墨化和产生局部明显蠕变裂纹,从而导致主蒸汽管道最终失效。

In order to avoid boiler accident and ensure safe operation of boiler, the importance of correct material selection for main steam pipe of power plant boiler is pointed out. The fracture and leakage accident of main steam pipe elbow of power station boiler in a chemical fiber factory is analyzed by using the correct material elbow and straight section pipe around the accident, using macroscopic inspection, wall thickness measurement, spectrum analysis and metallographic structure analysis It is pointed out that severe over temperature operation will lead to serious pearlite spheroidization, severe graphitization and local obvious creep cracks in the metal structure of the elbow of the main steam pipe of the carbon steel, which will lead to the final failure of the main steam pipe.