Crack growth prediction of stainless steel for low-cycle fatigue regime

In order to show validity of the strain intensify factor for predicting crack growth in the low-cycle fatigue regime, fatigue crack growth tests using Type 316 stainless steel in room temperature were reviewed. It was shown that the crack growth rates correlated well with the equivalent stress intensify factor, which was derived using strain range instead of stress range. Furthermore, the effective equivalent stress intensify factor derived using the effective strain range exhibited excellent correlation with the crack growth rates obtained under various specimen geometries and loading conditions including high and low-cycle regimens. The obtained crack growth rates were also compared with the growth rate prescribed in the fitness-for-service code of the Japan Society of Mechanical Engineers (JSME). The growth rate of JSME code agreed with the test results, although it depends on temperature. Finally, the procedure for predicting the low-cycle fatigue crack growth was shown. The JSME code growth prediction procedure and material constants can be used even for the low-cycle fatigue regime. (author)