A new mathematic approach is proposed to evaluate the temper embrittlement from the step cooling test. The approach is composed of two parts. A nonlinear model, which acts as weight factor, is used to fit the variance at different test temperatures, and the maximum likelihood method is used to determine the curve parameters. In the ASME specification SA-542, there is no instruction provided on how to determine the transition temperature from the test results. This method could be adopted as an additional supplementary requirement to assess the temper embrittlement of Chromium-Molybdenum steel.
Paper published with permission.