2.25Cr1Mo钢及其焊接接头在高温水蒸气中的应力腐蚀开裂敏感性研究  

SCC Susceptibility of 2.25Cr1Mo Steel and Its Weld Joints in High Temperature Steam

作　　者：刘宇桐 陈震宇 朱忠亮[1] 冯瑞 包汉生[3] 张乃强[1] LIU Yutong;CHEN Zhenyu;ZHU Zhongliang;FENG Rui;BAO Hansheng;ZHANG Naiqiang(Key Laboratory of Power Station Energy Transfer Conversion and System,North China Electric Power University,Beijing 102206,China;Nuclear Power Division,China Huaneng Group Co.Ltd.,Beijing 100031,China;Institute for Special Steels,Central Iron&Steel Research Institute,Beijing 100081,China)

机构地区：[1]华北电力大学电站能量传递转化与系统教育部重点实验室,北京102206 [2]中国华能集团公司核电事业部,北京100031 [3]钢铁研究总院特殊钢研究所,北京100081

出　　处：《中国腐蚀与防护学报》2022年第4期647-654,共8页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(52071140);中央高校基本科研业务费(2020MS007)。

摘　　要：对新型2.25Cr1Mo钢及其焊接接头的应力腐蚀开裂(SCC)敏感性进行研究,以评估其在换热管道中的适用性。以1×10^(-6)/s的应变速率分别在500℃/0.1 MPa的空气和水蒸气中进行了慢应变速率拉伸(SSRT)实验。通过扫描电镜分析断口、标距表面和横截面的形貌,通过能谱分析确定横截面氧化层的元素分布。结果表明,在500℃高温水蒸气中,焊接接头的抗拉强度和延展率低于母材,水蒸气环境下试样的延展率高于空气环境。所有试样均呈现单纯韧性断裂特征和较低的SCC敏感性,开裂仅发生在断口附近的氧化层内而未向基体延伸。此外,经SSRT后焊缝附近未发生开裂,焊接对SCC敏感性的影响不大。The stress corrosion cracking(SCC) susceptibility of a new type of 2.25Cr1Mo steel and its weld joints was studied by means of slow strain rate tensile(SSRT) tests at a constant strain rate of 1×10^(-6)/s in air and steam at 0.1 MPa/500 ℃ respectively, in order to evaluate its suitability for heat exchanging pipes. The morphology of fracture surface, gage surface and cross-section were analyzed by scanning electron microscopy(SEM). The element composition of oxide scales was determined by energy spectrum analysis(EDS). Experimental results showed that the tensile strength and elongation at break of weld joints were lower than that of base metal in steam at 500 ℃, whilst the elongation at break of which in high temperature steam was higher than that in air. All specimens exhibited features of simple ductile fracture and low SCC susceptibility, cracking occurred only in the oxide scale which was near the fracture, without extending to the matrix. In addition, cracking did not occur near the fusion boundary after SSRT. In conclusion, welding had little effect on SCC susceptibility.

关 键 词：2.25CR1MO钢 应力腐蚀开裂 高温水蒸气 焊接接头 

分 类 号：TM623[电气工程—电力系统及自动化]