Crack Propagation in Pipelines Under Extreme Conditions of Near-Neutral PH SCC  

作　　者：Abdullah Alsit Mohammad Alkhedher Hasan Hamdan 

机构地区：[1]Mechanical Engineering Department,College of Engineering,Abu Dhabi University,Abu Dhabi,59911,United Arab Emirates

出　　处：《Computers, Materials & Continua》2022年第12期5315-5329,共15页计算机、材料和连续体（英文）

基　　金：This work is supported by ASPIRE Award for Research Excellence(AARE 2019)under the Advanced Technology Research Council-ASPIRE through Project Number AARE19-098.

摘　　要：Stress Corrosion Cracking(SCC)process through which cracks occur in a variety of susceptible materials is a result of a combination of residual or applied stresses and corrosion.In oil and gas field,buried pipeline steels are made of low-alloy steels with a ferritic-pearlitic structure,such as X70.In dilute solutions,these materials are prone to SCC failure.The Near-neutral simulated soil solution(NS4)solution is established to imitate SCC conditions and subsequently became the industry requirement for crack growth experiments in the majority of laboratories.The strainassisted active crack pathways are considered while modelling SCC growth as an oxide film rupture and anodic dissolution process.It’s been hypothesized that increasing the strain concentration can help with dissolution at the filmfree crack tip.This research focuses on estimating the SCC crack growth rate under various environmental conditions in oil and gas pipelines using finite element modelling.The simulation is carried out using the J-integral theory in the COMSOL Multiphysics program.Simulations are performed to model the crack growth rate(CGR)using slip anodic dissolution(film rupture)mechanism.The plastic strain gradient is required to compute the SCC CGR(da/dt).Because the plastic strain located at crack tip increases proportionally to the crack length as it propagates,the CGR increases as the stress intensity factor(SIF)increases.The crack growth rates increase when constant loads are applied and as the temperature rises,and elevating the cathodic potential has a minimal influence on the propagation rate of cracks but raises the material yield strength and imparts brittle behavior to it.

关 键 词：Stress corrosion cracking SCC oxide film rupture and anodic dissolution crack growth rate CGR J-INTEGRAL stress intensity factor SIF 

分 类 号：TE97[石油与天然气工程—石油机械设备]