论文部分内容阅读
采用电子背散射技术研究了不同预处理状态的304奥氏体不锈钢经小压下(6%)冷轧和高温(1050℃)短时(5 min)退火后的晶界特征分布。结果表明,预先在1050℃下固溶30 min的合金样品经冷轧退火后其低Σ重位点阵晶界比例最高,达70%以上,较固溶状态提高了近20%,而且由互成Σ3n(n=0,1,2,3…)界面关系的晶粒团簇的尺寸明显增加,为晶粒平均尺寸的10～15倍。而未经固溶和固溶后在650℃下时效2 h的合金样品在后续的轧制退火过程中低Σ重位点阵晶界比例均有所下降,仅为40%～50%,而且Σ3n晶粒团簇尺寸为晶粒平均尺寸的2～5倍。分析认为,后两者未能实现晶界特征分布优化主要是由于碳化物的存在阻碍了晶界的迁移,尤其是非共格Σ3晶界和某些一般大角度晶界的广泛迁移所致。
The electron backscattering technique was used to study the grain boundary characteristic distribution of 304 austenitic stainless steels with different pretreatment conditions after cold rolling at low pressure (6%) and annealing at high temperature (1050 ℃) for a short time (5 min). The results show that the proportion of grain boundary at low Σ heavy bit is the highest, reaching more than 70% after the solution annealed at 1050 ℃ for 30 min, which is 20% higher than that of solid solution, The size of the grain clusters in Σ3n (n = 0, 1, 2, 3 ...) interface increases obviously, which is 10 ~ 15 times of the average grain size. However, the proportion of grain boundary at the low Σ weight bit during the subsequent rolling anneal decreased only 40% -50% when the samples were aged at 650 ℃ for 2 h without solution and solution treatment, and Σ3n crystal grain size of the average size of the grain 2 to 5 times. The analysis shows that the failure of the latter two to optimize the grain boundary distribution is mainly due to the fact that the existence of carbides hinders the migration of grain boundaries, especially due to the extensive migration of non-coherent Σ3 grain boundaries and some general large-angle grain boundaries.