初始碳化物对冷轧退火奥氏体不锈钢晶界特征分布的影响

The effect of initial carbide on grain boundary character distribution of the cold rolled and annealed 304 austenitic stainless steel

采用电子背散射衍射(EBSD)及扫描电子显微镜(SEM)研究了固溶及时效处理的304不锈钢经5%冷轧退火后,初始碳化物的存在对最终晶界特征分布的影响。结果表明,少量沿晶界不连续析出的碳化物对增加低∑3n(n=1,2,3)晶界比例和增大互成∑3n(n=0,1,2,3…)界面关系的特殊晶粒图簇尺寸没有负面影响。而随着初始碳化物分布数量和密度的增加,退火过程中形变亚结构消耗速度提高,以生成一般大角度晶界为特征的再结晶行为广泛发生,合金的晶界特征分布得不到优化。

The effect of initial carbide on grain boundary character distribution（GBCD） of the cold rolled and annealed 304 austenitic stainless steel previously treated by solid solution and aging was studied by electron back scatter diffraction（EBSD） and scan electron microscope（SEM）.The results show that a small amount of discontinuous carbide precipitation along grain boundary has no negative effect on enhancing the factions ofΣ3n（n=1,2,3） boundary and improving the size of the twinned grain cluster.However,when dense carbide precipitation is present in the initial microstructure,deformed substructure is consumed up at a higher rate during annealing and recrystallization featured by formation of numerous random high angle grain boundaries occurs extensively,and therefore well-optimized GBCDs can not be achieved.