Statistical Analysis of Creep Crack Growth Behavior in Modified 9Cr-1Mo Steel

Abstract:

In this paper, a series of statistical studies were conducted on creep crack growth behavior of Grade 9Cr-1Mo steel for next generation reactor. Creep crack growth tests were performed on pre-cracked compact tension (CT) specimens under the applied load ranges from 3800 to 5000N at the identical temperature condition of 600oC. The creep crack growth behavior has been analyzed statistically using the empirical equation between crack growth rate da/dt and C* parameter, namely da/dt=B(C*)q. First, the determination methods of B and q obtained from experiments were investigated by the least square fitting method and the mean value method. The probability distribution functions of B and q have been investigated using the normal, log-normal and Weibull distribution. The constant B and q are followed well 2-parameter Weibull. Second, the creep crack growth rate data were generated by Monte-Carlo simulation method assuming the 2-parameter Weibull in B and q parameters. The probability distribution of creep crack growth rate for arbitrary C* parameter values seems to follow well Weibull distribution.

• Periodical: Materials Science Forum (Volumes 654-656)
• Pages: 516-519
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.654-656.516
• Online since: June 2010
• Authors: Seon Jin Kim, Woo Gon Kim, Ik Hee Jung, Yong Wan Kim
• Keywords: 9Cr-1Mo Steel, C* Parameter, Creep Crack Growth Behaviour, Creep Crack Growth Rate (CCGR), Weibull Distribution

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