CHARACTERIZATION OF STRESS CORROSION CRACKING BEHAVIOR OF NITROGEN-CONTAINING 304NG STAINLESS STEEL IN HIGH TEMPERATURE WATER FOR STRUCTURAL INTEGRITY
Stress corrosion cracking (SCC) of stainless steels in high temperature water coolant has become a key problem affecting structural integrity of nuclear power systems in the world. In this work, the SCC behavior of nitrogen-containing steel 304NG in high temperature water environments has been characterized through investigating the effects of environmental factors (electrode potential and Cl- content) and heat treatment by means of slow strain rate testing (SSRT). The environments were pure water doped with 2, 5 and 50ppm Cl- at 250°C. For the steel in solution annealed state, the susceptibility to SCC at each Cl- level increased with increasing potential and there was a minimum potential for SCC, ESCC, below which no SCC occurred. The ESCC value decreased with the rise of Cl- content in the solution. The failure mode was transgranular cracking. The sensitization at 550°C for 730h caused high SCC susceptibility and intergranular cracking at potentials of +200mV or above in the solution with 5ppm Cl-, and also resulted in some transgranular SCC at -700mV. The mechanisms of the effects of environment and heat treatment are discussed.
G. F. Li Z.Y. Huang C.B. Huang G.L. Zhang W. YANG Y. WEN
Materials-Corrosion Lab, Shanghai Research Institute of Materials, 99 Handan Rd., Shanghai 200437, C National Key Laboratory for Nuclear Fuel and Material, Chengdu 610041, China.
国际会议
第九届工程结构完整性国际会议(The Ninth International Conference on Engineering Structural Integrity Assessment)
北京
英文
2007-10-15(万方平台首次上网日期,不代表论文的发表时间)