Abstract The present paper proposes a new computational model in which the Charpy impact property of steels is predicted from the microstructural information and tensile properties. During cleavage fracture, the Charpy impact property is controlled by the presence of a martensite-austenite constituent (MA) in the predominantly upper bainite microstructure in the weld heat-affected zone and is based on the weakest link mechanism and the micromechanics of the cleavage fracture. The cleavage fracture strength equation has been modified to statistically account for microcrack nucleation and propagation. An example calculation reveals that the proposed model reproduces the Charpy absorbed energy transition curve with a scatter in toughness. The validation of the model with experimental data is presented in the companion paper.

中文翻译：

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结合微观力学和随机断裂模型预测钢焊缝热影响区夏比冲击韧性 - 第一部分：模型介绍

摘要 本文提出了一种新的计算模型，该模型根据钢的显微组织信息和拉伸性能来预测钢的夏比冲击性能。在解理断裂过程中，夏比冲击性能受焊缝热影响区中以上贝氏体为主的显微组织中马氏体-奥氏体成分 (MA) 的存在控制，并基于最弱链接机制和解理断裂的微观力学. 解理断裂强度方程已被修改，以在统计上解释微裂纹的成核和传播。一个示例计算表明，所提出的模型再现了夏比吸收能量转换曲线，并且韧性分散。随附论文中介绍了使用实验数据对模型进行验证。