[1]倪志成,马鑫,张世豪,等.奥氏体不锈钢在压水堆一回路水环境中应力腐蚀研究进展[J].中国材料进展,2026,45(11):080-89.
　NI Zhicheng,MA Xin,ZHANG Shihao,et al.Research Progress on Stress Corrosion Cracking of Austenitic Stainless Steels in PWR Primary Water Environment[J].MATERIALS CHINA,2026,45(11):080-89.
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奥氏体不锈钢在压水堆一回路水环境中应力腐蚀研究进展()

中国材料进展[ISSN:1674-3962/CN:61-1473/TG]

卷:
45
期数:
2026年11
页码:
080-89
栏目:
出版日期:
2026-10-31

文章信息/Info

Title:
Research Progress on Stress Corrosion Cracking of Austenitic Stainless Steels in PWR Primary Water Environment
作者:
倪志成;  马鑫;  张世豪; 林鸿亮; 韩恩厚; 匡文军
1 华南理工大学材料科学与工程学院，广东 广州 510641 2 西安交通大学金属材料强度全国重点实验室，微纳尺度材料行为研究中心，陕西 西安 710049 3 广东腐蚀科学与技术创新研究院，广东 广州 510700 4 广东省高品质不锈钢技术研发企业重点实验室，广东 阳江 529500
Author(s):
NI Zhicheng;  MA Xin;  ZHANG Shihao;  LIN Hongliang et al.
1. School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China 2. Center for Advancing Materials Performance from the Nanoscale (CAMP-Nano), State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China et al.
关键词:
奥氏体不锈钢; 高温高压水; 应力腐蚀开裂; 水化学环境; 组织结构
Keywords:
Austenitic stainless steel;  high temperature and high pressure water;  stress corrosion cracking;  water chemical environment;  microstructure
文献标志码:
A
摘要:
奥氏体不锈钢是压水堆一回路关键结构材料，其在高温高压水中的应力腐蚀开裂（SCC）威胁核电机组延寿安全。本文综述该材料的SCC行为，聚焦裂纹萌生与扩展两阶段，系统总结了水化学条件与材料组织结构的影响。萌生机理以“晶界内氧化-脆化”为主：氧沿晶界渗入、Cr优先氧化形成内氧化区，应力致氧化晶界开裂并反复推进；晶界应变局域化产生的局部高应力协同驱动沿晶开裂。扩展机理以滑移-氧化模型为核心，裂尖氧化膜周期性破裂-再钝化，裂纹间断式扩展。在PWR一回路水中奥氏体不锈钢的裂纹扩展速率（Crack Growth Rate, CGR）一般在10-9~10-7 mm/s。水化学条件影响主要体现在：pH对SCC敏感性的影响呈U型，近中性条件（pH320℃≈7.0）下开裂敏感性最低；温度的影响与水化学参数相关，CGR在低氧水中随温度升高先增后减呈峰值效应，在含氧水中则单调上升；ppb级的Cl-/SO42-即可显著加速裂纹扩展，并与溶解氧（DO）存在协同效应；溶解氢（DH）的影响因加载方式而异；DO通过提升腐蚀电位加速裂纹扩展。组织结构：冷加工增加萌生敏感性，裂纹扩展速率随冷变形量、屈服强度与硬度的升高而单调增大；表面冷加工引入的细晶层可延缓SCC萌生；焊接接头的热影响区与熔合线因组织梯度和残余应变集中成为薄弱环节，焊缝δ-铁素体初始起抑制作用，热老化后反而促进扩展；晶界碳化物在还原性高温水中通过钉扎晶界和提供Cr抑制SCC，有别于氧化性水中因敏化促进开裂。目前，缺乏SCC萌生动力学的研究，DH/DO对SCC萌生与扩展的影响差异机理不清。未来需进行更加精细的研究和表征工作，建立精确预测模型，支撑延寿评估。
Abstract:
Austenitic stainless steels are key structural materials for the primary circuit of pressurized water reactors (PWRs). The susceptibility to stress corrosion cracking (SCC) of these materials in high-temperature high-pressure water threatens the safety of nuclear power plant life extension. This paper reviews the SCC behavior of these materials, focusing on the two stages of crack initiation and growth, and systematically summarizes the effects of water chemistry conditions and material microstructure. The prevalent initiation mechanism is preferential intergranular oxidation–embrittlement: oxygen penetrates along grain boundaries; chromium is preferentially oxidized to form intergranular oxide and the oxidized grain boundary fractures under stress. In such way, the crack advances repeatedly. The local high stress generated by grain boundary strain localization synergistically drives intergranular cracking. The growth is mainly governed by the slip-oxidation mechanism, in which the crack-tip oxide film periodically ruptures and repassivates, and the crack advances in a stepwise manner. In PWR primary water, the crack growth rate (CGR) of austenitic stainless steels typically ranges from 10-9 to 10-7 mm/s.The effects of water chemistry conditions are as follows: The influence of pH on SCC susceptibility exhibits a U-shaped trend, with the lowest cracking sensitivity under near-neutral conditions (pH at 320℃ ≈ 7.0). The effect of temperature is coupled with water chemistry parameters: in low-oxygen water,crack growth rate first increases and then decreases with rising temperature, showing a peak effect; while in oxygen-containing water, it monotonically increases. Cl- or SO42- at ppb levels can significantly accelerate crack propagation, exhibiting a synergistic effect with dissolved oxygen (DO).The influence of dissolved hydrogen (DH) varies depending on the loading mode. DO accelerates crack propagation by elevating the corrosion potential. Microstructure effects: Cold work increases SCC initiation susceptibility, while the crack growth rate increases monotonically with increasing degree of cold work, yield strength, and hardness. the ultrafine-grained (UFG) layer introduced by surface cold working can suppress SCC initiation. In welded joints, the heat-affected zone (HAZ) and fusion line become weak points due to microstructural gradients and residual strain concentration. Weld δ-ferrite initially suppresses SCC but promotes its propagation after thermal aging. Grain boundary carbides inhibit SCC in reducing high-temperature water by pinning grain boundaries and supplying Cr, which differs from their role in oxidizing water where sensitization promotes cracking. There is currently a lack of research on SCC initiation kinetics, and the mechanisms underlying the different effects of DH/DO on SCC initiation versus propagation remain unclear. Future work requires more refined investigations and characterization to establish accurate predictive models,supporting life extension assessments.
更新日期/Last Update: 2026-09-28