Computerized Time-Temperature Parametric Analysis of C, Mo, and Cr-Mo Steel Stress-Rupture Data

Abstract

Demonstrated by results obtained with highly modified or original computer programs, accomplished with 31 data sets for C, Mo, and Cr-Mo steels, is the general superiority of the new Goldhoff-Sherby and the older Manson-Haferd parameters for the correlation of stress-rupture data, as compared with the use of the Larson-Miller, Sherby-Dorn, Manson-Succop, Conrad, and Korchynsky methods. Abilities to correlate are based on values of statistical measures of scatter about master curves. Rupture-times in excess of 10,000 hr were used in separate computer runs to test the abilities of the seven parameters to extrapolate to longer times. For extrapolation the Goldhoff-Sherby and Manson-Haferd parameters are generally superior, but particular attention must be paid to the order of the polynomial used to approximate master curves.