Volume 21, Issue 4 (July 1993)
Initiation and Stable Crack Growth Behavior of API X70 Steel at Low Temperatures (25°C ≥ T ≥ −95°C)
Small-scale tests employing single edge notch bend (SENB) specimens of API X70 pipeline steel were conducted to assess the initiation and stable growth behavior of this material at test temperatures between 25°C and −95°C. Material resistance curves were generated based on various proposed J-integral and crack tip opening displacement (CTOD) relationships and criteria for defining crack initiation and stable growth. DC potential drop crack growth monitoring was employed to provide crack propagation data for development of the resistance curves. The temperature dependence of crack initiation and stable growth properties of this material are quantified and presented. Verification of the temperature independence of the normalized J or CTOD tearing modulus is also provided.