金属材料局部腐蚀损伤过程的近场动力学模拟:进展与挑战

Modeling Localized Corrosion Propagation of Metallic Materials by Peridynamics:Progresses and Challenges

金属材料的局部腐蚀损伤是制约其服役寿命和服役安全性的关键因素。目前已有的局部腐蚀评价主要基于实验室腐蚀模拟实验和实际环境腐蚀暴露实验,往往面临实验复杂度高、周期较长及经费高等缺点。随着局部腐蚀电化学理论、局部腐蚀研究方法的不断完善,以及数值计算和相应模拟软件、编程语言的快速发展,局部腐蚀模拟仿真得以实现。基于经典连续力学(classical continuum mechanics,CCM)的数值模型,采用空间微分方程描述物质点之间的作用,在求解腐蚀损伤等不连续问题时会出现奇异性。近场动力学(peridynamics,PD)是一种基于非局部思想的理论,其采用时间微分-空间积分描述物质点之间的作用,突破了CCM理论在不连续问题上的瓶颈。结合基于PD理论的局部腐蚀损伤模型的相关理论和数值实现方法,本文综述了PD局部腐蚀模型在点蚀、缝隙腐蚀、晶间腐蚀、电偶腐蚀及应力腐蚀开裂中的应用,并分析其所面临的挑战并指出未来的研究方向。

Localized corrosion degradation of metallic materials is a key factor that significantly impacts their lifetime and safety.Existing localized corrosion assessment methods for metallic materials are mainly based on corrosion simulation experiments in laboratory and corrosion exposure experiments in real environmental.However,these experiments are often complex,lengthy,and costly.Localized corrosion simulation can be achieved with the continuous improvement in the theory and measurement of localized corrosion,and the rapid development of numerical calculation,simulation software,and programing.Numerical models based on the classical continuum mechanics(CCM)apply a spatial differential equation to describe the interaction between material points,and singularity appears when solving discontinuous problems such as corrosion degradation.The peridynamics(PD)theory based on nonlocal applies time differential-spatial integration to describe the interaction between the material points and breaks through the bottleneck of the CCM theory on discontinuous problems.This paper reviews the state of the art of PD applied in localized corrosion modeling,including pitting corrosion,crevice corrosion,intergranular corrosion,galvanic corrosion,and stress corrosion cracking by combing with the relevant theories and numerical implementations of the localized corrosion degradation model based on the PD theory.Finally,the challenges and outlook of PD applied in corrosion modeling are discussed.