Stress corrosion cracking

About: Stress corrosion cracking is a research topic. Over the lifetime, 11340 publications have been published within this topic receiving 138157 citations.

A phase field formulation for dissolution-driven stress corrosion cracking

Abstract: We present a new theoretical and numerical framework for modelling mechanically-assisted corrosion in elastic–plastic solids. Both pitting and stress corrosion cracking (SCC) can be captured, as well as the pit-to-crack transition. Localised corrosion is assumed to be dissolution-driven and a formulation grounded upon the film rupture–dissolution–repassivation mechanism is presented to incorporate the influence of film passivation. The model incorporates, for the first time, the role of mechanical straining as the electrochemical driving force, accelerating corrosion kinetics. The computational complexities associated with tracking the evolving metal–electrolyte interface are resolved by making use of a phase field paradigm, enabling an accurate approximation of complex SCC morphologies. The coupled electro-chemo-mechanical formulation is numerically implemented using the finite element method and an implicit time integration scheme; displacements, phase field order parameter and concentration are the primary variables. Five case studies of particular interest are addressed to showcase the predictive capabilities of the model, revealing an excellent agreement with analytical solutions and experimental measurements. By modelling these paradigmatic 2D and 3D boundary value problems we show that our formulation can capture: (i) the transition from activation-controlled corrosion to diffusion-controlled corrosion, (ii) the sensitivity of interface kinetics to mechanical stresses and strains, (iii) the role of film passivation in reducing corrosion rates, and (iv) the dependence of the stability of the passive film to local strain rates. The influence of these factors in driving the shape change of SCC defects, including the pit-to-crack transition, is a natural outcome of the model, laying the foundations for a mechanistic assessment of engineering materials and structures.

Fundamental aspects of corrosion films in corrosion science

Abstract: 1. Thermodynamics of Corrosion.- 2. Kinetics of Corrosion.- 3. Properties of Corrosive Films.- 4. Corrosion Inhibition and the Role of Films.- 5. Films and Pitting Corrosion.- 6. Role of Films in Stress Corrosion Cracking and Hydrogen Embrittlement.- 7. Role of Films in Erosion-Corrosion.

Transgranular Stress Corrosion Cracking of X-80 and X-52 Pipeline Steels in Dilute Aqueous Solution with Near-Neutral pH

Abstract: Slow strain rate tests (SSRT) and fractographic examination of X-80 and X-52 pipeline steels showed transgranular stress corrosion cracking (TGSCC) could occur in a dilute aqueous solution...

A study on the SCC susceptibility of friction stir welded AZ31 Mg sheet

Abstract: In this study, the stress corrosion cracking (SCC) behaviour of a friction stir welded (FSW) AZ31 Mg alloy was examined using the slow strain rate tensile (SSRT) test method. Electrochemical impedance spectroscopy (EIS) and salt spray tests were conducted to understand the general and localized corrosion behaviour of the base material and the FSW joint. It was found that the FSW AZ31 Mg samples exhibited higher SCC susceptibility than the base material under SSRT testing in the corrosive environment. The failure of these FSW AZ31 Mg samples occurred in the stir zone (SZ), whereas failure occurred in the thermo mechanically affected zone (TMAZ) for samples tested in air. The EIS and salt spray test results demonstrate that the SZ exhibits higher uniform and pitting corrosion resistance than the base material. The present study suggests that the hydrogen assisted cracking mechanism predominates in the failure of FSW AZ31 Mg samples during SSRT test in the corrosive environment.