Prediction method of creep curves and creep life.

摘要

PROBLEM TO BE SOLVED: To provide a method of predicting an overall creep curve and a creep lifetime by evaluating a distortion speed change from any arbitrary portion in the creep curve.;SOLUTION: A prediction method of a creep curve includes a first step of performing a creep test on a material to determine a time dependent curve of creep distortion, a second step of determining a relationship between the creep distortion and a distortion speed from the obtained creep curve, a third step of determining a differentiation value (d) in any arbitrary distortion portion from a curve obtained by differentiating or approximating a logarithmic distortion curve while regarding it as a distortion function, a fourth step of determining a curvature, that is, distortion acceleration factor α in the arbitrary distortion portion from the curve obtained by differentiation or approximation, and a fifth step of obtaining a creep curve by substituting the determined values (d) and α into a differentiation equation obtained from a definition expression of the distortion acceleration factor α and performing integration. According to a prediction method of a creep lifetime, the time in which the distortion speed becomes high rapidly is regarded as a break time.;COPYRIGHT: (C)2013,JPO&INPIT