Corrosion sensitization behavior and mechanical properties of liquid -nitrogen-deformed austenitic 304 stainless steel

Julio Gerardo Maldonado, University of Texas at El Paso

Abstract

Plastic deformation of 304 stainless steel at liquid nitrogen temperature $({-}196\sp\circ$C) produces an almost complete transformation to strain-induced $\alpha\sp\prime/$-martensite which provides the necessary conditions for a pseudo-recrystallization of the microstructure. This "so-called" pseudo-recrystallization results directly from the martensitic reversion (i.e. martensite to austenite reverse transformation) upon the application of heat treatment within the sensitization temperature range. The very fine duplex $(\alpha/\gamma)$ microstructure which results (after heat treatment--0.1h-670$\sp\circ$C) is also accompanied by a very extensive and homogeneous precipitation of chromium-rich carbides. The concomitant pseudo-recrystallization and precipitation processes not only have a profound positive effect on the sensitization behavior, but also affect the mechanical properties of the material. This suggests that 304 stainless steel could be thermo-mechanically treated, to in essence, heal itself and simultaneously produce an extremely fine ($\approx$0.1$\mu$m) duplex grain structure with intermixed carbides to form a very high strength product. This might have important practical implications since 304 stainless steel is the material of choice in many engineering applications. Electrochemical testing, transmission electron microscopy, scanning electron microscopy, optical microscopy, neutron diffraction, X-ray diffraction, and mechanical testing were some of the techniques employed in this work. ^

Subject Area

Engineering, Metallurgy|Engineering, Materials Science

Recommended Citation

Maldonado, Julio Gerardo, "Corrosion sensitization behavior and mechanical properties of liquid -nitrogen-deformed austenitic 304 stainless steel" (1997). ETD Collection for University of Texas, El Paso. AAI9819584.
http://digitalcommons.utep.edu/dissertations/AAI9819584

Share

COinS