A Statistical Model of Cleavage Fracture Toughness of Ferritic Steel DIN 22NiMoCr37 at Different Temperatures

Abstract

It is a conventional practice to adopt Weibull statistics with a modulus of 4 for characterizing the statistical distribution of cleavage fracture toughness of ferritic steels, albeit based on a rather weak physical justification. In this study, a statistical model for cleavage fracture toughness of ferritic steels is proposed according to a new local approach model. The model suggests that there exists a unique correlation of the cumulative failure probability, fracture toughness and yield strength. This correlation is validated by the Euro fracture toughness dataset for 1CT specimens at four different temperatures, which deviates from the Weibull statistical model with a modulus of four.

A scaling approach to size effect modeling of J CDF for 20MnMoNi55 reactor steel in transition temperature region

“…The Beremin local model [18,19] was developed in attempt to pursue a statistical approach to the inherently stochastic fracture by taking into account the salient micromechanical features in the process. Many aspects of this influential model, its shortcomings and necessary corrections, were discussed recently by Qian et al [20]. Wallin [21,22] performed more detailed analysis which resulted in the two-parameter Weibull model known as the Master Curve model.…”

“…The Prometey model [25,26], in its advanced form, involved very complex statistical treatment of micromechanics assuming that both the microcrack nucleation and the microcrack propagation were driven by stochastic parameters. The model development involved "intricate series of assumptions and formulations" [20]. Lei [27,28] offered an influential critical assessment of the three above-mentioned local models, with emphasis on physical justification of the widely adopted selection of Weibull model parameters.…”

Non-hardening embrittlement mechanism of pressure vessel steel Ni-Cr-Mo-V welds during thermal aging

“…The future work will be developing a framework of lifetime prediction considering thermal aging mechanism for engineering structures. [23][24][25][26][27][28][29] Some new designs of the structures inspired from composite materials made with the additive manufacturing technique may be helpful for future RPV material. 30,31…”

Study on cleavage fracture probability-load curves of ferritic steel 20MnMoNi55 by using the new local approach model

“…According to Eqs. (1) and (2), it can be seen that when the cleavage fracture does not occur, the minimum value of the failure probability is non-zero. Clearly, this doesn't make sense in terms of both probability theory and physics.…”

“…Ferritic steels are commonly used to make nuclear pressure vessels. Due to the hostile service environment, ferritic steels are prone to cleavage fracture [1,2], which will lead to many serious accidents [3]. In order to further study cleavage fracture, French Beremin group proposed a local approach model (LAM) of cleavage fracture [4], which was called the Beremin model [5].…”