Evaluation of microstructure and mechanical property of high strength Fe-Ni-Cr-Al alloys depending on thermo-mechanical processing

Abstract

As an ATF cladding material, Fe-Ni-Cr-Al alloys, alumina-forming duplex stainless steels were developed. Because ADSS alloys had duplex (austenite and ferrite) and B2-NiAl precipitates, the microstructure was considerably affected by thermo-mechanical processing. Thus, by setting three different TMP conditions, microstructure and mechanical properties were evaluated. At 1000, 1100 and 1200⁰C, microstructural evolution was evaluated. Phase fraction, grain size, precipitate size and fraction were quantified. For evaluating mechanical properties, tensile and hardness test were conducted. By using fracture surface analysis and quantification of microstructure, relationship between mechanical properties and microstructure was discussed.