国产主蒸汽管道用P92钢的持久性能研究

Study on Creep-rupture Property of P92 Steel in Domestic Main Steam Pipes

对3个批次主蒸汽管道用P92钢开展了系列温度和应力条件下的持久试验,其中最长持久试验时间达到28000 h。分别采用等温线法、Larson-Miller参数法和Wilshire法对持久性能进行预测,采用等温线法外推的结果介于后两种方法之间,采用Larson-Miller参数法的预测结果高于实际试验数据,而采用Wilshire法的预测结果过于保守。根据试验数据和日本国立材料研究所(NIMS)数据的比较情况以及3种预测方法的10万h持久性能预测结果,认为国产P92钢的持久性能与NIMS和欧洲蠕变委员会(ECCC)的数据比较接近。在进行长时持久性能预测时应选择合适的预测方法,且采用分区处理方法可以提高预测精度。

Creep-rupture test at different temperature and stress was performed for three batches of main-steam pipe P92 steel,in which the longest creep-rupture test lasted for 28000 hours.Isotherm method,Larson-Miller method and Wilshire method were used to predict their creep-rupture property.The extrapolate results of isotherm method were somewhere in between.The Larson-Miller method overestimates the results while the predictions by Wilshire method are more conservative.According to all test data,the data from National Institute for Materials Science(NIMS),and the predicted creep strength by three methods in 100000 hours,the creep-rupture property of domestic P92 steel is close to the data from NIMS and European Creep Collaborative Committee(ECCC).Suitable prediction method is critical for predicting the creep-rupture property in a long term.The prediction precision can be enhanced by dividing the data into short-term and long-term.