Abstract

Colossal N supersaturation of ferritic as well as austenitic stainless steels during low temperature gaseous nitridation treatments has lately gained much technological significance. However, available thermodynamic models to calculate the N paraequilibrium solubility limits have failed to explain the levels of colossal N supersaturation observed in several cases of nitrided ferritic/austenitic stainless steels. In this work, we show that consideration of N dissolution induced spinodal decomposition is essential in calculating the N paraequilibrium solubility limit for both ferritic and austenitic stainless steels. This modification in the thermodynamic model has led to the successful explanation of the thermodynamic cause for the colossal N supersaturation in ferritic and austenitic stainless steels. Available experimental observations in literature support the occurrence of spinodal decomposition.

Details

Title
Thermodynamic reasoning for colossal N supersaturation in austenitic and ferritic stainless steels during low-temperature nitridation
Author
Sasidhar, K N 1 ; Meka, S R 2 

 Indian Institute of Technology Roorkee, Department of Metallurgical and Materials Engineering, Roorkee, India (GRID:grid.19003.3b) (ISNI:0000 0000 9429 752X) 
 Indian Institute of Technology Roorkee, Department of Metallurgical and Materials Engineering, Roorkee, India (GRID:grid.19003.3b) (ISNI:0000 0000 9429 752X); Max-Planck-Institut für Eisenforschung GmbH, Department Microstructure Physics and Alloy Design, Düsseldorf, Germany (GRID:grid.13829.31) (ISNI:0000 0004 0491 378X) 
Publication year
2019
Publication date
2019
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2232161555
Copyright
© The Author(s) 2019. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.