未投用锅炉部件珠光体球化原因分析探讨

Analysis of Pearlite Spheroidization on Un-served Boiler Component

对电厂未投用受热面管和集箱进行金相检验,发现部件有不同程度的珠光体球化。选取异常试样进行化学成分分析、力学性能试验和不同区域金相检验,并对部分球化试样重新热处理。发现制造过程中热处理偏差会引起珠光体球化,热加工会加剧球化级别,一般不超过1级。建议A级锅炉厂材料复验时增加金相检验,出现球化时应判断交货级别。不同球化等级钢材在微观组织和力学性能上存在差异,掌握参数变化对锅炉寿命及安全评估有重要意义。

During the metallographic inspection of un-served boiler steel tubes and headers,it was found that the pressure-containing member appears pearlite spheroidization in different degrees.After sampling the main steel tubes with abnormal metallographic structure,conduct chemical analysis,mechanical performance test,and metallographic analysis are carried out.Then,heat treatment is carried out once again with partially spheroidized sample.The analysis results show that the implementation deviation of heat treatment will bring pearlite spheroidization and the hot procedure will aggravate the proceeding pearlite spheroidization,which is about one grade additional.Finally,the added pearlite spheroidization is put forward for A boiler works during the course of receiving.The microstructure and macro-mechanical properties have vary significantly with the degree of pearlite spheroidization.So it is important to master the material attenuation of the senescence process,which will provide useful and targeted improvement to life and safety assessment of boiler.