【摘要】 采用慢应变速率拉伸试验(SSRT)与断口形貌分析技术研究304N不锈钢(固溶退火态)在300℃高温水中的应力腐蚀行为与机理。结果表明:304N在300℃高温水中的最大抗拉强度、延伸率以及断裂吸收能随Cl-浓度的增大显著降低;随氧浓度的急剧降低而显著增大;304N在高温水中发生应力腐蚀开裂(SCC)主要为穿晶型;随Cl-浓度增加,304N的应力腐蚀敏感性也迅速增加,在含50mg/L Cl-的空气饱和高温水环境中,试样断口形貌表现为完全脆断;在溶解氧浓度急剧降低时,氯致应力腐蚀开裂的敏感性大幅降低,表明溶解氧对304N在高温水中的氯致应力腐蚀开裂具有明显的促进作用。更多还原

【Abstract】 The stress corrosion cracking(SCC) behavior and mechanism of solution-treated 304N stainless steel in high temperature water were studied by slow strain rate tensile test(SSRT) and fracture surface analysis.The results show that the SCC beha-vior of 304N in high temperature water reveals as transgranular cracking,and with the increasing of Cl-content,the susceptibility of SCC increases.The specimen shows brittle fracture mode when it is exposed to high temperature aerated water containing 50 mg/L Cl-.The present results also indicate that the susceptibility of chloride induced-SCC decreases significantly with decreasing of dissolved oxygen(DO) content in water,which reveals that DO plays a significant role in promoting SCC of 304N in high temperature water.更多还原