Nano-ferrite formation and strain-induced-ferrite transformation in an SUS316L austenitic stainless steel

• Published in: Scripta materialia 2000-08, Vol.44 (8-9), p.2039-2042
• Main Authors: Fujiwara, H, Inomoto, H, Sanada, R, Ameyama, K
• Format: Article
• Language: English
• ISSN: 1359-6462

Grain refinement is an effective method for an improvement of the mechanical property. Recently the grain refinement by the powder metallurgy process has received much attention. The high strain powder metallurgy (HS-PM) process is one of the new processes combining mechanical milling, mechanical alloying, heat treatment and sintering processes. The process has three interesting features. Firstly a heavy cold deformation by the milling treatment results in a non-equilibrium phase. Secondary a nano grain structure can be obtained from non-equilibrium phases by controlling the heat treatment condition, which influences the phase transformation, recovery, recrystallization and grain growth. Lastly it has a good workability because of the fine grain structure. Therefore, the HS-PM process is the most efficient and useful non-equilibrium powder metallurgy process because both an improvement of mechanical property and workability by the control of microstructure are simultaneously possible. In this study, the HS-PM process was applied to an SUS316L austenitic stainless steel powder, and the nano ferrite grain structure formation is discussed.