The δ to γ Transition in Fe-Cr-Ni Alloys during Laser Treatment
The δ to γ Transition in Fe-Cr-Ni Alloys during Laser Treatment
复制标题
Fe-Cr-Ni 合金在激光处理过程中的 δ 到 γ 转变
DOI：
10.2355/isijinternational.37.677
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发表时间：
1997
影响因子：
1.8
通讯作者：
W. Kurz
中科院分区：
文献类型：
--
作者：
Shigeo Fukumoto;W. Kurz
对Fe-18%Cr-Ni合金进行了激光重熔试验，研究了成分(Cr/Ni值在1.3~1.83之间)和生长速度(0.90~50 mm/S)对初生δ-铁素体和初生γ-奥氏体凝固组织选择的影响。实验结果与树枝晶生长模型的理论预测进行了比较。铁素体向奥氏体相转变的实验结果与Ni含量增加和生长速度加快的理论符合得很好。发现在较低的Ni含量下，奥氏体相变到铁素体相变发生。认为δ-γ相变不存在形核障碍，受枝晶生长动力学控制，γ-δ相变受铁素体形核控制。
Laser remelting experiments have been performed with Fe-18%Cr-Ni alloys to evaluate the effects of composition (Cr/Ni ratios between 1.30 and 1.83) and growth velocity (0.9 to 50 mm/s) on the microstructure selection during solidification between primary δ-ferrite and primary γ-austenite. The experimental results are compared with theoretical predictions from a dendrite growth model. The experimental transitions from ferrite to austenite are in good agreement with theory for both an increase in Ni content and increase in growth rate. The transitions from austenite to ferrite are found to occur at lower Ni contents than predicted. It is thought that the δ-γ transition shows no nucleation barrier and is controlled by dendrite growth kinetics and the γ-δ transition is controlled by nucleation of ferrite.