On the origin of subgrain boundaries during conventional solidification of austenitic stainless steels
On the origin of subgrain boundaries during conventional solidification of austenitic stainless steels
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DOI：
10.1088/1757-899x/373/1/012005
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发表时间：
2018-06
期刊：
影响因子：
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通讯作者：
R. Rahimi;H. Biermann;O. Volkova;J. Mola
中科院分区：
文献类型：
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作者：
R. Rahimi;H. Biermann;O. Volkova;J. Mola
在传统的铸造和不锈钢凝固过程中的亚晶形成的起源进行了研究，使用两个奥氏体不锈钢与0和4质量%的Al。而无Al合金显示没有亚晶形成，Al添加合金开发了高密度的亚晶分离的小角度晶界。在添加Al的合金中的亚晶的发生是合理的，其铁素体凝固模式的热力学计算预测和确认的动态扫描量热法测量。亚晶可能是流体流动导致的软初生铁素体枝晶塑性变形及其随后的奥氏体遗传的结果。可替代地，它们可能已经在从δ铁素体形成奥氏体期间被诱导，最有可能经由包绕反应。无铝合金中亚晶的存在是由其奥氏体凝固模式证明的。
The origin of subgrain formation during conventional casting and solidification of stainless steels was studied using two austenitic stainless steels with 0 and 4 mass-% Al. Whereas the Al-free alloy showed no subgrain formation, the Al-added alloy developed a high density of subgrains separated by low-angle grain boundaries. The occurrence of subgrains in the Al-added alloy was justified by its ferritic mode of solidification as predicted by thermodynamic calculations and confirmed by dynamic scanning calorimetry measurements. The subgrains might be a consequence of the plastic deformation of soft primary ferrite dendrites by the fluid flow and their subsequent inheritance by the austenite. Alternatively, they might have been induced during the austenite formation from delta ferrite, most likely via a peritectic reaction. The absence of subgrains in the Al-free alloy was justified by its austenitic mode of solidification.