Time-dependent crack growth in stainless steel 304 in the plasticity-dominant field

Abstract

Time-dependent crack growth is investigated at 538 degreesC on compact tension specimens of stainless steel 304 under constant loads and alternating tensile loads with identical hold times. Finite element analyses of crack growth are performed following the experimental crack growth history. It is found, for the load levels employed, that plastic deformation is dominant around the crack tip throughout the test duration. Test results indicate that, for alternating load tests, most of crack growth occurs at the upper load and that crack growth is retarded by periodic load changes. It is shown that crack growth rates are not correlated with J, but with rate parameters J and C-pc proposed in this study. The minimum crack extension for validity of the correlation varied from test to test but was always less than 0.35 mm. (C) 2001 Elsevier Science Ltd. All rights reserved.