Dissolution of Nitrides and Precipitation of an AusteniticPhase on the Surface of Fe-20%Cr alloys
2010 (English)Report (Other academic)
New phases have been observed on surfaces of metal specimens duringcooling after heat treatment at 1200, 1300 and 1400 °C of an Fe-20mass% Cr alloywith different nitrogen contents (65, 248 and 490 ppm) and deoxidised by Ti andZr. These phases were assumed to be related to a phase transformation. Theanalysis of nitrogen content in matrix metal and new phase crystals was carried outbased on point analysis of nitrogen using SEM. According to obtained results itwas concluded that the nitrogen had been dissolved from the nitrides during 60minutes of heat treatment at high temperature and diffused in to the matrix. Theseareas of enriched nitrogen content were then transformed to a new phase duringcooling. This new phase was assumed to be austenite because the nitrogen is a wellknown element for promotion of austenite formation. The possibility of austeniteformation in Fe-20mass% Cr alloys with different nitrogen content was consideredand confirmed thermodynamically by using the Thermo-Calc software.
Place, publisher, year, edition, pages
Stockholm: KTH , 2010. , 30 p.
, KTH/MSE, 1015
ferritic stainless steel, high Cr alloy; Ti and Zr deoxidation; N content, austenite
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-13335OAI: oai:DiVA.org:kth-13335DiVA: diva2:323739