SIMPLIFIED STABLE CRACK-GROWTH ANALYSES OF WELDED CT SPECIMENS - COMPARISON STUDY OF GE EPRI, REFERENCE STRESS AND R6 METHODS/

This paper describes some simplified stable crack growth analyses of t wo kinds of inhomogeneous CT specimens. The one is machined from a sub merged are welded plate of a nuclear pressure vessel A533B Class 1 ste el, while the other is machined from an electron-beam welded plate of the A533B Class 1 steel and a high strength HT80 steel. In both specim ens, initial cracks are placed to be normal to the fusion line. The ra tio of yield stresses of the weld metal and the base metal of the A533 B Class 1 steel is about 1 . 15, while that of the HT80 and the A533B Class 1 steels is about 1 . 4. The generation phase crack growth analy ses using the GE/EPRI and the reference stress methods are performed, calculating an applied load (P) and the J-value, while the application phase analyses of analyses using the R6 method are performed to calcu late the maximum value of the applied load (P-max). Finally, some modi fication procedures of the three simplified estimation schemes are dis cussed in order to apply them to inhomogeneous material regimes.