pH值对高温高压水中304L不锈钢应力腐蚀开裂的影响

Effects of pH values on the stress corrosion cracking of 304L stainless steel in high-temperature and high-pressure water

摘要: 在高温高压水环境中,采用慢应变速率拉伸试验方法,研究了不同pH值对304L不锈钢应力腐蚀开裂行为的影响规律,并通过扫描电镜对试样断口形貌进行观察与分析.结果表明:在300℃时,304L不锈钢在弱酸性和弱碱性溶液中的应力腐蚀开裂敏感性较大,且酸性越强,敏感性越大.在中性溶液中,304L不锈钢的强度和塑性损失较小,应力腐蚀敏感性较小,断口分析与之吻合.

Abstract: The effects of pH values on the stress corrosion cracking(SCC) of 304L stainless steel in high-temperature and high-pressure water were studied using slow strain rate tension(SSRT) tests.The fracture morphology of SCC specimens was analyzed with the aid of scanning electron microscopy(SEM).It is shown that 304L stainless steel exhibits a high susceptibility to SCC in weak alkaline and acidic solutions at 300 ℃, and the susceptibility increases by decreasing the pH value of the solution.In neutral solutions, both the strength and toughness of 304L stainless steel display a limited loss, indicating that 304L stainless steel has a low susceptibility to SCC.Fractography analysis is also consistent with these conclusions.