摘要
为研究核电关键结构在服役过程中不同裂尖形貌的应力腐蚀开裂裂尖的微观力学状态。根据氧化膜破裂理论,以具有较好的高温耐腐蚀性的核电关键结构材料奥氏体不锈钢304L为实验材料,以影响核电关键结构破坏和失效的主要形式之一的应力腐蚀开裂为研究对象,根据ATEM技术得到微观尺度下的裂纹裂尖形貌和结构特征,利用有限元分析方法对其含氧化膜SCC裂纹尖端微观力学状态进行了初步分析。结果表明裂尖氧化膜的形状对裂尖氧化膜和基体上的应力应变影响很大,随着氧化膜裂尖和基体金属裂尖之间的距离的增大,氧化膜上的高应力区增大,而基体上的减小。氧化膜裂尖区域应力远大于基体金属裂尖区域,所以应定义氧化膜裂尖为裂尖进行分析。模拟结果为精确预测核电一回路结构材料应力腐蚀开裂扩展速率奠定一定基础。
It＇s analyzed that is kinds of micro-mechanical state of stress corrosion cracking（ SCC） tip in nuclear plant in-service key structure. Based on the oxide film rupture model and taken austenitic stainless steel 304 L that has high temperature corrosion resistant properties as experimental material,regarding SCC that is one of the main forms of affecting the damage and failure of nuclear power key structure as a research object,by analytical transmission election microscopy we obtained shape and structure in micro scale,and analyzed SCC tip in the micro-mechanical state by FEM. Results show that the oxide film shape at crack tip influence the stress and strain of the oxide film and base material. With the increase of the distance between oxide film crack tip and base metal crack tip,the high stress area of film increases and that of base decreases. The stress in film crack tip is much higher than base crack tip,therefore film crack tip should be defined as the crack tip. The simulation provides a foundation to improve the quantitative prediction of SCC growth rate in a circuit structure materials of nuclear power plants.
出处
《西安科技大学学报》
CAS
北大核心
2016年第3期380-384,共5页
Journal of Xi’an University of Science and Technology
基金
国家自然科学基金(51475362)
国家教育部博士点基金(20136121110001)
关键词
核电结构材料
奥氏体不锈钢
应力腐蚀开裂
应力应变
有限元
nuclear structure materials
austenitic stainless steels
stress corrosion cracking
stress-strain
FEM
