氧氯协同对304L不锈钢在高温高压硼锂水中应力腐蚀开裂的影响

采用高温高压慢应变速率拉伸试验方法(SSRT),研究了饱和氧环境下不同氯离子浓度对304 L不锈钢在高温高压硼锂水介质中氯致应力腐蚀开裂的影响。结果表明:在一定浓度范围内有氧无氯或者有氯无氧环境下,304L不发生应力腐蚀开裂。在空气饱和氧条件下,氯离子浓度在1 mg/L至10 mg/L之间变化时,应力腐蚀敏感性随浓度变化不大;而当氯离子浓度大于20 mg/L时,应力腐蚀敏感性随浓度的增加变化很大,当氯离子浓度为50 mg/L,304L几乎完全为脆性断裂。

Effect of Oxygen and Chloride Cooperation on Stress Corrosion Cracking of 304L Stainless Steel in High Temperature and high Pressure Water Containing Boric Acid and Lithium Ion

Stress corrosion cracking (SCC) of stainless steel 304L in different chloride ion concentrations in air-saturated oxygen atmosphere was studied using slow strain rate testing (SSRT). The basic water chemistry was simulated in pressure water reactor (PWR) primary loop. High temperature and high pressure water contains boric and lithium ion. Results show that within a certain range of concentrations, the SCC does not occur in air-saturated oxygen without chloride ion or in chloride ion solution without oxygen. In air-saturated oxygen with chloride ions ranging from 1 mg/L to 10 mg/L, the SCC susceptibility of 304L changes a little with chloride ion concentration. When the chloride ion concentration reaches to 20 mg/L, the SCC susceptibility of 304L changes very much with the increasing of chloride ion concentration. When the chloride ion concentration is 50 mg/L, 304L is almost brittle fracture