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Role of Na 2 CO 3 on an AISI 330 austenitic stainless steels oxidation at 900°C
Author(s) -
Buscail Henri,
Issartel Christophe,
Riffard Fréderic,
Perrier Sébastien,
Rabaste Francoise,
Poble Olivier,
Combe Cécile
Publication year - 2019
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.201810567
Subject(s) - materials science , alloy , oxidizing agent , austenite , silicon , sodium carbonate , niobium , metallurgy , sodium , amorphous silica , amorphous solid , chemical engineering , chemistry , microstructure , crystallography , organic chemistry , engineering
This study shows the influence of sodium carbonate coatings on the austenitic AISI 330 (Fe–35Ni–19Cr–1.3Si) oxidized during 48 hr at 900°C. The N 2 ‐5 vol% H 2 gaseous environment was used to simulate industrial heat treatment conditions. Silica scale formation is promoted by low oxygen‐containing gaseous environments and the high alloy silicon content. On this alloy, an amorphous silica scale is formed after the blank material oxidation. It indicates that silicon is free to diffuse in the alloy and forms a silica scale at the internal interface. On Na 2 CO 3 ‐coated specimens, no silica scale is formed. Then, sodium combines with silicon to form amorphous glass particles. A comparison has been performed with results obtained on a AISI 330Cb niobium containing alloy in the same oxidizing conditions. It is then concluded that sodium carbonate coatings could only favor silica formation on niobium containing alloy due to a reaction between sodium and niobium.