Reliability analysis and life prediction of HK40 steel during high-temperature exposure

This paper is concerned with reliability analysis and residual life prediction of HK40 austenitic steel based on their creep rupture data by introducing a Z-parameter method. A normal distribution is supported for the value of the Z-parameter and the distribution curves of tubes after service exposure have been shown to deviate to the right with an increase in service time. According to creep rupture data both from different segments of a long-term service tube and from the same segment locations after different service time, it is proven that the Z-parameter reflects the deterioration in creep rupture properties. Residual life prediction and damage evaluation by Z-parameter method based on confidence level are also presented.