论文部分内容阅读
针对700℃超超临界汽轮机候选材料镍基合金Inconel 625,在700~750℃空气和水蒸气交替环境以及在0~8000μg/L溶解氧浓度的高温水蒸气环境下进行应力腐蚀裂纹扩展速率(CGR)实验研究。采用恒应力强度因子(K)的力学加载方式进行加载,采用直流电位降法(DCPD)对CGR进行在线检测。结果表明:Inconel625合金在水蒸气环境中的CGR比空气环境中的大,温度越高CGR越大;随着水蒸气中溶解氧含量的增加,CGR增大。并对温度、介质环境和溶解氧含量对应力腐蚀开裂CGR的影响机理进行了讨论。
In this paper, the stress corrosion crack growth rate (CGR) of Inconel 625, a candidate material for ultra-supercritical steam turbine at 700 ℃, was investigated under the conditions of alternating air and water vapor at 700-750 ℃ and high temperature water vapor at 0-8000 μg / L dissolved oxygen concentration )Experimental Study. The mechanical loading method of constant stress intensity factor (K) was used to load, and the CGR was detected online by DC potential drop method (DCPD). The results show that CGR in Inconel625 alloy is larger than that in air, and the higher the CGR, the higher the CGR. The CGR increases with the increase of dissolved oxygen in steam. The effects of temperature, media environment and dissolved oxygen on the mechanism of stress corrosion cracking (CGR) were also discussed.