论文部分内容阅读
通过晶界工程(GBE)处理,可使304不锈钢样品中的低∑CSL晶界比例提高到70%(Palumbo Aust标准)以上,同时形成了大尺寸的“互有∑3~n取向关系晶粒的团簇”显微组织.采用C型环样品恒定加载方法,在pH值为2.0的沸腾20%NaCl酸化溶液中进行应力腐蚀实验.GBE样品在平均浸泡472 h后出现应力腐蚀裂纹,SEM,EBSD和OM分析表明,应力腐蚀开裂(SCC)为沿晶开裂(IGSCC)和穿晶开裂(TGSCC)的混合型.而未经GBE处理的样品在平均浸泡192h后出现多条应力腐蚀主裂纹,且多为沿晶界裂纹.经过GBE处理的样品中大尺寸的晶粒团簇及大量相互连接的∑3-∑3-∑9和∑3-∑9-∑27等∑3~n类型的三叉界角,阻碍了IGSCC裂纹的扩展,从而提高了304不锈钢样品的抗IGSCC性能
The grain boundary engineering (GBE) treatment resulted in the increase of the low ΣCSL grain boundary ratio in the 304 stainless steel sample above 70% (Palumbo Aust standard), and the formation of large-size Σ3 ~ n interdependent crystal Particle cluster "microstructure.The stress corrosion experiments were carried out in a constant temperature C-ring loading method in a boiled 20% NaCl acidified solution at a pH of 2.0.The stress corrosion cracking occurred in the GBE samples after an average immersion of 472 h, SEM, EBSD and OM analysis show that SCC is a mixed type of intergranular cracking (IGSCC) and transgranular cracking (TGSCC), while samples without GBE show multiple stress corrosion main after 192h immersion Cracks and many cracks along the grain boundary.The large size of the grain clusters in GBE-treated samples and a large number of interconnected Σ3-Σ3-Σ9 and Σ3-Σ9-Σ27 Σ3 ~ n Type trigeminal angle hindered the expansion of IGSCC cracks and thus improved the IGSCC resistance of 304 stainless steel samples