摘要
采用慢应变速率试验(SSRT)测试了模拟压水堆核电厂一回路水中硫酸根离子(SO_(4)^(2–))质量浓度对Z3CN20.09铸造奥氏体不锈钢(CASS)应力腐蚀开裂(SCC)敏感性的影响。测试结果表明:Z3CN20.09不锈钢在6种水环境中进行SSRT后断口附近都出现不同程度的颈缩现象;在不含SO_(4)^(2–)的正常压水堆(PWR)水质中,不锈钢的破断延伸率最大,断裂面均为韧窝状的断口,SCC抗力强;高温水中SO_(4)^(2–)质量浓度为100~1 500μg/L时,SSRT断口出现明显的SCC现象,断口表现为脆性+韧窝混合型;不同相及相界对SO_(4)^(2–)腐蚀的敏感性和SO_(4)^(2–)对合金表面钝化膜的劣化作用是促进Z3CN20.09铸造奥氏体不锈钢局部腐蚀和SCC的重要因素。
By slow strain rate test(SSRT),the effect of sulfate mass concentration in primary circuit water of the pressurized water reactor(PWR) on stress corrosion cracking(SCC) sensitivity of Z3CN20.09 casted austenitic stainless steel(CASS) was investigated.The results show that,necking occurred near the fracture after the SSRT of Z3CN20.09 CASS in 6 water environments.In normal PWR water containing no SO_(4)^(2–),the elongation to fracture of Z3CN20.09 CASS was the largest,and the rupture surfaces were dimple-like facets,indicating that the Z3CN20.09 CASS has excellent SCC resistance under this condition.SSRT samples showed significant SCC sensitivity in high-temperature water containing 100~1 500 μg/L SO_(4)^(2–),and the fracture showed transgranular plus dimple mixed face.The corrosion sensitivity of different phases and phase boundaries to SO_(4)^(2–) and the deterioration effect of SO_(4)^(2–) on passive film on the alloy surface are thought to be the key factors for enhancing localized corrosion and SCC.
作者
张锦浙
陈红雨
张裕
吴迪
ZHANG Jinzhe;CHEN Hongyu;ZHANG Yu;WU Di(Daya Bay Nuclear Power Operation and Management Co.,Ltd.,Shenzhen 518124,China)
出处
《热力发电》
CAS
CSCD
北大核心
2022年第9期162-169,共8页
Thermal Power Generation
基金
中国广核集团有限公司尖峰计划项目(R-2020SZSO53TF)。
关键词
压水堆核电站
不锈钢
应力腐蚀开裂
高温水
硫酸根离子
PWR nuclear power station
stainless steel
stress corrosion cracking
high-temperature water
sulfate ion
