Investigation of the circumferential stress corrosion cracking mechanism in pipeline materials

加拿大管道公司拥有并运营着横跨加拿大的10万多公里大直径输电管道，将天然气和液化石油产品输送到北美市场。确保管道网络的安全运行对于满足推动加拿大社会的能源需求具有重要的经济和环境意义。钢质管道材料大多埋在地下，容易发生腐蚀降解。管道故障代价高昂，通常会造成能源损失、碳排放，对环境、生态和社区造成影响。管线钢的一种关键退化模式是应力腐蚀开裂(SCC)，它是指在腐蚀和拉应力共同作用下产生的材料的开裂。本项目将重点研究残余应力和局部化学的贡献，以了解管线钢中近中性pH应力腐蚀开裂的机理，重点是环向裂纹。加拿大境内广泛的大直径输电管道网络满足了数百万消费者的能源需求。因此，确保管网的安全运行对满足推动加拿大社会的能源需求具有重要的经济和环境意义。

Canadian pipeline companies own and operate more than 100,000 kilometers of large diameter transmission pipelines across Canada, transporting natural gas and liquid petroleum products to North American markets. Ensuring safe operation of the pipeline network is of great economic and environmental importance to meet the energy requirement that drives Canadian society. Mostly buried underground, steel pipeline material is prone to experience corrosion degradation. Pipeline failures are costly, usually resulting in energy loss, carbon emission, impacts to environment, ecology and community. A key degradation mode in pipeline steel is stress corrosion cracking (SCC), defined as cracking of a material produced by the combined action of corrosion and tensile stress. This project will focus on studying the contribution of residual stresses and local chemistry to understand the mechanism of near-neutral pH SCC in pipeline steel, with a focus on circumferential direction cracking. The extensive network of large diameter transmission pipelines across Canada provide for the energy needs of millions of consumers. Therefore, ensuring safe operation of the pipeline network is of great economic and environmental importance to meet the energy requirement that drives Canadian society.