Method and device for simulating metal surface hydrogenation spot corrosion morphology evolution

Abstract

The invention discloses a method and device for simulating metal surface hydrogenation spot corrosion morphology evolution, and the method comprises the steps: building a hydrogenation spot corrosion phase field model coupled with anisotropic elastic energy through employing an anisotropic elastic constant, and constructing an equivalent elastic constant through employing an interpolation function method to represent the non-uniformity of a system; the method is suitable for anisotropic metal materials, can simulate the morphology difference caused by elastic anisotropic growth of the metal materials, and better shows the growth morphology characteristics of hydrogenation point corrosion; in the pitting corrosion phase field model, a finite element method is adopted to solve a mechanical equilibrium equation of a non-periodic boundary condition, and the problem of non-periodic physical parameter periodicity caused by Fourier transform solving of a periodic elastic field can be avoided.

Description

technical field [0001] The invention relates to the technical field of hydrogenation corrosion of metals, in particular to a method and a device for simulating the evolution of hydrogenation pitting corrosion morphology on a metal surface. Background technique [0002] Pitting corrosion of hydrides on metal surfaces leads to material failure. Hydrogen corrosion is a kind of chemical corrosion, and once the corrosion occurs, a phase structure of different components will be formed. The nucleation and precipitation of hydrides usually occur near the passivation layer / metal interface, and the hydrogenation reaction of metal M goes through M+x[H]=MH x occurs, where [H] is hydrogen dissolved in the metal or passivation layer, and x is the H / M ratio. The hydrogenation process is mainly divided into three stages, the early stage: the nucleation stage, the initial stage of hydride formation depends on the adsorption, dissociation and migration of hydrogen; the middle stage: the gr...

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Problems solved by technology

The electrochemical pitting corrosion phase field model of 304 stainless steel proposed by Qasim et al. considers the accompanying current conduction phenomenon in the electrochemical corrosion process of 304 stainless steel by introducing electric field energy and electric field equation, but ignores the important role of elastic energy on corrosion morphology, and Yang et al. Although the isotropic elastic energy is solved based on the periodic Fourier transform, it is not suitable for anisotropic metal materials, and cannot well reflect the shape difference caused by the elastic anisotropic growth of metal materials. At the same time, the periodic The non-periodic boundary will cause the periodization of the aperiodic physical parameters, which is not in line with the actual simulation situation

At the same time, the solution of periodic Fourier transform is not suitable for metal materials in more complex working environments. For example, when considering the internal force of the material itself or the external stress on the boundary, etc., its setting will inevitably cause some problems, and even interfere with the results. correctness

In addition, Yang et al. set the isotropic elasticity of two different materials with the same Young's modulus and Poisson's ratio, which is inconsistent with the inhomogeneous elasticity corresponding to the heterogeneous material in the actual situation.

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