Atomistic simulations with interatomic potentials can provide insights into the cracking and failure of structural ferritic steels. Unfortunately, the evaluation of the simulation results often suffers from the uncertainties due to the quality and behavior of the employed interatomic potential. In this work, the molecular dynamics (MD) method has been used to simulate and to analyze the deformation and propagation of crack tips in α-iron. The influence of different types of potentials that we adopt on the crack propagation simulation is discussed. State of art M07, M20, and B20 potentials are considered. Overall, the microscopic deformation mechanism by the MD simulation with different types of potentials are similar, which dislocations are emitted from the crack tip, and twinning or martensite transformation happen. However, with a careful contradistinction, different mechanical responses are investigated. The relationship between the cracking mechanism and the intrinsic properties of α-iron, such as stacking fault energies, has also been discussed.

具有原子间势的原子模拟可以深入了解结构铁素体钢的开裂和失效。不幸的是，由于所采用的原子间势的质量和行为，模拟结果的评估经常受到不确定性的影响。在这项工作中，分子动力学（MD）方法已被用于模拟和分析裂纹尖端在α-铁。讨论了我们采用的不同类型的电位对裂纹扩展模拟的影响。考虑了最先进的 M07、M20 和 B20 潜力。总体而言，不同类型势能的MD模拟微观变形机制相似，都是从裂纹尖端发射位错，发生孪晶或马氏体相变。然而，仔细对比，研究了不同的机械响应。还讨论了开裂机制与α-铁的固有特性（如堆垛层错能）之间的关系。