Hydrogen Transport and Trapping Mechanisms Controlling Embrittlement of Nickel Alloys in Low Carbon Energy Systems

许多当前和下一代能源系统是依赖于生产、运输、存储和使用气态氢,通常在高压力。这种系统的安全性、耐用性、性能和经济运行都受到挑战，因为氢会促进高性能材料的各种降解模式。这种降解通常表现为破坏金属和聚合物结构完整性的开裂；一种因降解的时间和操作周期（如应力、氢压力和温度）依赖性而变得复杂的行为。例如，在典型的压力容器或管道环境条件下，同时应力和氢气暴露会导致现代金属系统以十分之一的断裂韧性开裂。这种氢引起的降解现象一般被归类为氢脆。在过去的100年里，科学界进行了大量的工作，氢损伤现象的广度和重要性并没有被忽视。这是一个广泛的跨学科问题，涉及到冶金学、化学、固体力学和断裂力学、表面科学、分子和原子氢物理、无损检测、材料表征和机械性能测试。尽管这是一项重要的工作，但管理复杂工程结构暴露在苛刻的环境和机械载荷条件下的人员面临着重大挑战。这里的挑战是将氢损伤机制的争论转变为材料开裂性能的定量预测模型。包罗万象的这些挑战是不可避免的事实,氢损伤问题是非常复杂的,需要时间周期的理解相关流程操作在原子尺度影响的行为体现在宏观尺度。

Many current and next generation energy systems are reliant on the production, transportation, storage and use of gaseous hydrogen, often at high pressure. The safety, durability, performance, and economic operation of such systems are challenged due to the reality that hydrogen promotes a variety of degradation modes in otherwise high performance materials. Such degradation is often manifested as cracking which compromises the structural integrity of metals and polymers; a behaviour complicated by time and operating cycle (e.g., stress, hydrogen pressure, and temperature) dependencies of degradation. As an example, concurrent stressing and hydrogen exposure at typical pressure vessel or pipeline environmental conditions can promote cracking in modern metallic systems at one-tenth the fracture toughness. Such hydrogen-induced degradation phenomena are generally categorised as hydrogen embrittlement. The breadth and importance of hydrogen damage phenomena have not gone unnoticed in the scientific community with an immense amount of work conducted over the past 100 years. The problem is broadly interdisciplinary and such work has involved metallurgy, chemistry, solid mechanics and fracture mechanics, surface science, molecular and atomic hydrogen physics, non-destructive inspection, materials characterisation, and mechanical-properties testing. This important work notwithstanding, major challenges face those tasked with managing complex engineering structures exposed to demanding environment and mechanical loading conditions. The challenge here is to transform debate on mechanisms of hydrogen damage into a focus on quantitative, predictive models of material cracking properties. Overarching these challenges is the inescapable fact that hydrogen damage problems are immensely complex, requiring understanding of time-cycle dependent processes operating at the atomic scale to impact behaviour manifest at the macroscopic scale.