Analysis of Nanometer-Scale Precipitation in a Rapidly Solidified Stainless Steel

• Published in: Microscopy and microanalysis 1997-08, Vol.3 (S2), p.981-982
• Main Authors: Wisutmethangoon, S, Kelly, TF, Camus, PP, Flinn, JE, Larson, DJ, Miller, MK
• Format: Article
• Language: English
• ISSN: 1431-9276; 1435-8115
• DOI: 10.1017/S143192760001179X

Though stainless steels are important technologically for a wide range of applications, they are not generally known for their very high strength. We have rapid-solidification-processed many stainless steels by gas atomization and achieved strength improvements of over 50% relative to conventionally-processed stainless steels with concomitant improvement in corrosion and oxidation behavior. These strength improvements are most pronounced after aging treatments when elevated concentrations of oxygen and vanadium are present in the stainless steel. An austenitic (FCC) stainless steel (Fe-16%Ni-9%Cr-0.5%Mn-0.2%V-0.0137%N-0.008%O by weight) was prepared by gas atomization and consolidated by hot extrusion at 900°C. These specimens were heat treated for 1 hour at 1000°C and aged at 600°C for 500 hours. The microstructure of each alloy composition was observed in TEM with bright field imaging. After aging, most alloys showed the same precipitate morphology as before aging. An obvious change, however, was found only in the alloy with highest oxygen content.