晶界碳化物和冷变形对600合金应力腐蚀开裂的影响规律  

Effect of Grain Boundary Carbides and Cold Work on Stress Corrosion Cracking of Alloy 600

作　　者：汪家梅 苏豪展 陈凯[1] 郭相龙 张乐福[1] 王元华 马武江 WANG Jiamei;SU Haozhan;CHEN Kai;GUO Xianglong;ZHANG Lefu;WANG Yuanhua;MA Wujiang(School of Nuclear Science and Engineering Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Xinmin(Dongtai)Heavy Forging Co.,Ltd.,Suzhou 224200,China)

机构地区：[1]上海交通大学核科学与工程学院,上海200240 [2]上海新闵(东台)重型锻造有限公司,江苏224200

出　　处：《腐蚀与防护》2022年第4期1-6,46,共7页Corrosion & Protection

基　　金：国家重点研发项目(2017YFB0702203,YS2018YFE010246);自然科学基金(51871153)。

摘　　要：采用直流电位降(DCPD)在线监测方法研究了晶界碳化物和冷变形对600合金在高温水环境中应力腐蚀开裂(SCC)裂纹扩展速率的影响规律,并结合高分辨微观表征技术阐明了作用机理。结果表明:无冷变形时,晶界碳化物能通过阻挡裂纹向基体内部扩展和抑制晶界氧化而有效降低600合金的SCC敏感性;冷变形后,晶界残余应变和晶界碳化物周围产生的局部应变集中,促进了氧元素扩散、加速晶界氧化,进而加速裂纹扩展。The stress corrosion cracking(SCC) behavior of alloy 600 in simulated pressurized water reactor(PWR) high-temperature water environment was investigated by direct current potential drop(DCPD) on-line monitoring. Analytical electron microscopy was utilized to characterize the cracking process to better understand the cold work and grain boundary(GB) carbides effect. Synergistic effect of GB carbides and cold work on SCC behavior was identified. A beneficial effect of carbides was identified in non-cold worked alloy 600, which was attributed to the physical impediment and reduced GB internal oxidation. In cold worked alloy 600, GB carbides had a detrimental effect due to the combination of the enhanced local strain at GBs and also enhanced GB internal oxidation.

关 键 词：600合金 碳化物 冷变形 应力腐蚀开裂 裂纹扩展速率 

分 类 号：TL341[核科学技术—核技术及应用]