Samrin Saiyara

Advisor: Prof. Josh Kacher

will propose a doctoral thesis entitled,

Hydrogen Reduction of Mixed Metal Oxides for Solid-State Alloy Formation of Stainless Steel 

On

Thursday, May 14 at 9:30 a.m.

Love Room 295

And

 Virtually via MS Teams 

https://teams.microsoft.com/meet/215969704040016?p=93wAJQ4kuW2sm3JNv5

Committee

            Prof. Josh Kacher – School of Materials Science and Engineering (advisor)

            Prof. Naresh Thadhani– School of Materials Science and Engineering

            Prof. Robert Speyer – School of Materials Science and Engineering

            Prof. Preet Singh – School of Materials Science and Engineering            

            Prof. Chaitanya Deo – School of Mechanical Engineering

Abstract

Hydrogen reduction of metal oxides offers a promising pathway to carbon- and energy-efficient ferrous alloy and steel production, but the high cost of hydrogen often makes this route economically untenable. One path forward is a process-intensification approach involving extrusion-based net-shape fabrication of alloy steels, starting with oxide components, followed by their reduction and sintering, resulting in the metal/alloy product. In this work, we study the coreduction behavior of the binary Fe-18Cr alloy, relevant to the common 316L stainless steel system. A central challenge is the reduction of chromium oxide (Cr₂O₃), a highly stable oxide that often remains partially unreduced, thereby limiting alloy homogeneity. While the early reduction of iron oxide (Fe₂O₃) can promote chromia reduction by acting as a sink for newly formed chromium, it can also hinder complete reduction by driving extensive Fe sintering, which encapsulates residual Cr oxides and restricts gas transport, thereby limiting further reduction.  Preliminary results show that chromia particle size and sample thickness strongly influence reduction behavior. This work aims to gain a deep understanding of the interplay among thermodynamics, gas transport, and microstructural evolution that governs coreduction, using advanced characterization techniques such as SEM, XRD, and TEM to probe phase and interfacial evolution. The findings will guide strategies to achieve full reduction and inform the design of oxide-dispersed steels through the controlled incorporation of stable nanoscale oxides, ultimately advancing a scalable, low-carbon pathway for steel production.