The proposal of Q* parameter and derivation of the law of creep crack growth life for a round bar specimen with a circular notch for Cr–Mo–V steel

Abstract

Using a round bar circular notched specimen for Cr–Mo–V steel and the proposed equation predicting crack length on the basis of electric potential drop method, the creep crack growth tests were previously conducted to investigate the effect of multi-axial stress on creep crack growth rate(CCGR). In this paper, more detailed experiments and analyses on the creep crack growth were conducted and the Q* parameter which characterizes CCGR for this circular notched specimen was derived. Furthermore, using the Q* parameter, the prediction law of creep crack growth life was also derived.

Keywords:

• Q* parameter
• creep crack growth rate
• creep crack growth life
• round bar specimen
• circular notch
• electric potential drop method
• multi-axial stress