Inclusion rating by statistics of extreme values and its application to fatigue strength prediction and quality control of materials

The inclusion rating method by statis-tics^ extreme values (IRMSE) using y/area of inclusions as the size parameter enables one to discriminate between current super-clean steels. Moreover, IRMSE enables one to predict the size {y/area-m,^ of maximum inclusions contained in domains larger than the inspection domain. The statistical di.'itribution of s/area^, can be used for the quality control of materials and for the prediction of a scatter band of fatigue strength. Practical procedures of inclusion rating and prediction of a scatter band of fatigue strength arc shown.