High pH Stress Corrosion Cracking (HpHSCC) was identified in the 1960s for the first time and is considered to be a significant threat for buried pipelines. When certain specific conditions arise in the pipeline’s environment and loading it leads to intergranular cracking on the axial-radial plane. These cracks can grow under continued adverse loading and eventually result in fast rupture or leakage. Large numbers of field investigations, experimental studies, and simulations have been conducted to delineate and understand the circumstances that lead to HpHSCC. This paper will provide a review of the circumstances, conditions, and events that pipelines experiencing HpHSCC may undergo during the course of this phenomenon. HpHSCC cracks failure happens over an extended time period, and the life cycle of the vulnerable pipe involves five sequential stages viz. incubation stage, crack initiation and early stage of crack growth, preparation stage for mechanically derived crack growth, sustainable crack growth caused by mechanical driving force, and rapid crack propagation to failure. This paper discusses the mechanisms at each stage of HpHSCC from the environmental, metallurgical, and mechanical loading points of views. The interactions and sometimes synergistic effects of different parameters are discussed during the entire life cycle of the pipes. The central focus of this review is to correlate the events at each stage of crack propagation to loading conditions and their variability, which play a crucial role in estimating the remaining life of the susceptible linepipe to HpHSCC. The discussion will include how the cyclic-loading conditions can alter the steel properties and assist in intergranular crack initiation. The changes in the geometry of subcritical cracks and subsequent alteration in mechanical driving force for crack propagation are detailed. The contributing mechanisms that cause sustainable crack growth are expanded. The modeling of HpHSCC crack growth is discussed and outlined. The gaps in knowledge about HpHSCC are highlighted at the end along with necessary future research to improve the modeling of HpHSCC.

高pH应力腐蚀开裂（HpHSCC）于1960年代首次被发现，被认为是对地下管道的重大威胁。当管道的环境和负载中出现某些特定条件时，会导致轴向径向平面上的晶间裂纹。这些裂纹会在持续的不利载荷下增长，并最终导致快速破裂或泄漏。为了描述和理解导致HpHSCC的情况，已经进行了大量的现场调查，实验研究和模拟。本文将对在这种现象过程中经历HpHSCC的管道可能发生的情况，条件和事件进行回顾。HpHSCC裂纹失效会持续很长时间，即潜伏期，裂纹萌生和裂纹扩展的早期阶段，机械衍生裂纹扩展的准备阶段，由机械驱动力引起的可持续裂纹扩展以及快速裂纹扩展至失效。本文从环境，冶金和机械负荷的角度讨论了HpHSCC各个阶段的机理。在管道的整个生命周期中，讨论了不同参数的相互作用以及有时产生的协同效应。这篇综述的重点是将裂纹扩展的每个阶段的事件与载荷条件及其可变性相关联，这在估计易受影响的管道对HpHSCC的剩余寿命中起着至关重要的作用。讨论将包括循环载荷条件如何改变钢的性能并有助于晶间裂纹的产生。详细介绍了亚临界裂纹的几何形状变化以及随后裂纹扩展的机械驱动力的变化。扩大了导致裂纹持续扩展的作用机制。讨论并概述了HpHSCC裂纹扩展的模型。最后强调了有关HpHSCC知识的空白，并进行了必要的未来研究以改进HpHSCC的建模。