Thermodynamic studies of the Fe-Cr-C-N system by EMF measurements
2007 (English)In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Metallurgical and materials transaction B, Vol. 38, no 1, 93-100 p.Article in journal (Refereed) Published
In this work, the Fe-Cr-C-N alloys were synthesized by nitriding the Fe, Cr, and C powder mixtures at 1573 K in the N-2 gas (101 325 Pa). The nitrogen content and phase relationships at 1173 K in the alloys were investigated by the use of an equilibration technique. The thermodynamic activities of chromium in the alloys were studied using the solid-state galvanic cell method with CaF2 as the solid electrolyte in the temperature range 973 to 1173 K in an atmosphere of N-2 gas (101 325 Pa). The activities of chromium in the Fe-Cr-C-N alloys were calculated and compared with those of the corresponding Fe-Cr-C ternary alloys with pure bcc-Cr as standard state. X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods were used to identify the equilibrium phases and microstructures of the investigated alloys. The experimental results show that a Cr2N-based nitride was formed during the nitriding procedure in the alloys. The nitrogen content in the alloys decreases with the decreasing chromium content, as well as the increasing temperature. The addition of nitrogen to the ternary Fe-Cr-C alloy was found to have a strong negative impact on the Cr activity in the Fe-Cr-C-N system.
Place, publisher, year, edition, pages
2007. Vol. 38, no 1, 93-100 p.
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-6592DOI: 10.1007/s11663-007-9019-4ISI: 000246113900010ScopusID: 2-s2.0-34247554322OAI: oai:DiVA.org:kth-6592DiVA: diva2:11344
QC 201009292006-12-122006-12-122010-09-29Bibliographically approved