【作者】 刘金华； 龚宾； 姜峨； 赵永福；

【Author】 LIU Jin-hua;GONG Bin;JIANG E;ZHAO Yong-fu;Nuclear Power Institute of China;Institute of Nuclear Science and Technology,Sichuan University;

【机构】 中国核动力研究设计院； 四川大学原子核科学技术研究所；

【摘要】 通过慢应变速率拉伸（SSRT）试验,开展溶解氧含量对奥氏体不锈钢310 S拉伸性能和应力腐蚀开裂（SCC）的敏感性研究。SSRT测试在超临界水中进行,温度为620℃,压力为25 MPa,应变速率为7.5×10^-7S⁽-1_。试验结果表明,随着溶解的氧浓度的增加,延伸率大幅下降。电镜下观察到断口为脆性断裂模式,仅发现有晶间腐蚀开裂。裂纹广泛分布于310S整个标距段,最大的裂纹深度随氧浓度的增加而增加。对标距段裂纹处氧化膜进行EDS分析,铬含量随溶解氧浓度的增加而显著增加。裂纹内氧化物具有双层结构,外层为富铁氧化物,内层为富铬氧化物。更多还原

【Abstract】 The effects of dissolved oxygen content on the tensile properties and stress corrosion cracking(SCO susceptibility of austenitic stainless steel 310 S were studied by performing Slow Strain Rate Tensile（SSRT） tests.The SSRT tests were carried out in supercritical water at temperature of 620 ℃,a pressure of 25 MPa,and a strain rate of 7.5×10^-7 s^-1.The results show that the elongation decreased dramatically with the increasing of dissolved oxygen concentration.A brittle fracture mode was observed on the fracture surface,and only intergranular cracks were found on the gauge surface.Cracks on 310 S were widely distributed over the whole gauge section and the highest crack depth increased with the oxygen concentration.The Cr content the oxide layer on the surface showed significant increase with the increasing of DO concentration.Oxides in the cracks with two-layer structures were observed,an outer Fe-rich oxide layer and an inner Cr-rich oxide layer.更多还原