It is one of the effective ways to obtain excellent comprehensive performance of 2205 duplex stainless steel (DSS) to adjust the volume ratio and grain size of α and γ phases. In the present paper, 2205 DSSs with micro-nano structures were successfully prepared by aluminothermic reaction under appropriate Fe₂O₃ excess conditions, and the formation mechanism of micro/nano structures was studied from the aspects of the preparation process, element equivalent, and residual Al content. Here, the Cr_eq/Ni_eq ratio of the 2205 DSS is 2.09, indicating that the solidification mode belongs to mode F, that is, L → L + α→α→α + γ. The residual Al content and the volume percentages of α and γ phases and their grain sizes can be controlled by reasonably adjusting the excess percentage of Fe₂O₃. When the excess percentage of Fe₂O₃ is 5.0%, the volume percentages of α and γ phases reach the minimum and maximum values, respectively. However, when there is a large amount of unreacted Al in the alloy or an inappropriate excess percentage of Fe₂O₃ for preparation, only the α phase is contained in alloys.

调节α和γ相的体积比和晶粒尺寸是获得2205双相不锈钢（DSS）优异综合性能的有效方法之一。本文通过在适当的Fe ₂ O ₃过量条件下通过铝热反应成功制备了2205种具有微纳米结构的DSS ，并从制备工艺，元素当量和结构等方面研究了微/纳米结构的形成机理。残余铝含量。此处，Cr _eq / Ni _eq2205 DSS的比率为2.09，表明凝固模式属于模式F，即L→L +α→α→α+γ。通过合理地调整Fe ₂ O ₃的过量比例，可以控制Al的残留量，α相和γ相的体积百分比以及它们的晶粒尺寸。当Fe ₂ O ₃的过量百分比为5.0％时，α相和γ相的体积百分比分别达到最小值和最大值。然而，当合金中存在大量未反应的Al或用于制备的Fe ₂ O _3的过量百分比过多时，合金中仅包含α相。