蠕变断裂寿命外推方法及数据分散性处理研究

摘要

高温部件的蠕变寿命外推问题是高温结构完整性领域的重要课题.主要归纳了蠕变断裂寿命的外推方法,介绍以Larson-Miller参数法为代表的长时持久寿命外推方法;同时,给出其他常用寿命外推方法;最后,介绍蠕变断裂寿命外推过程中数据分散性的处理方法.结果表明,使用Larson-Miller法外推耐热钢长时持久寿命时存在过高估计倾向,利用分区分析方法可显著改善外推结果.蠕变断裂数据不可避免存在分散性,可以从试验方法、数据选择和常数优化等方面减小数据分散,此外引入Z参数,在一定可靠度下进行寿命预测.%The extrapolation of the creep rupture life is an important issue of high temperature structure integrity.Extrapolation of creep rupture life methods represented by Larson-Miller parameter(LMP) method is summarized,and the processing methods of creep rupture data scattering is introduced.Results indicate that creep rupture life of heat-resistant steel is usually overestimated by the LMP method,while multiregion analysis could improve extrapolation results;data scattering could be reduced in the aspects of experimental method,data selection and constant optimization.In addition,creep rupture life can be predicted using the Z parameter with the reliability included.