Corrosion at 7000C of metals and alloys exposed to NbCl5 vapor
Creators
- 1. Centre National de la Recherche Scientifique, 94 - Vitry (France). Centre d'Etudes de Chimie Metallurgique
Description
The electrochemical reduction of NbCl5 performed at 7000C in a molten salt bath for obtaining niobium has shown that all metallic elements present in the cell are corroded. In such conditions the electrolysis produces only a Ni3Nb alloy and never pure metallic niobium. To determine the effect of NbCl5, we have studied the oxidation of metals (M = Ni, Cr, Nb, Fe, Ti) and alloys (NSMC-NS21C-NS22S-NS30-Inconel 600) put in vapors of niobium pentachloride. For the pure metal M this corrosion is limited by the formation of pure or mixed dichloride (M, Nb) Cl2. Nickel and chromium are the most resistant in this atmosphere. The alloys with metal M as the main component show a much more important corrosion than pure metal. More ever the amount of corrosion is always too weak to explain the big production of NiCl2 that appears when a cell is continuously fed with NbCl5. We study now the same metals and alloys put in a molten salt bath having different concentrations in NbCl5. 6 refs.; 8 figs.; 3 tabs
Abstract (French)
L'obtention du niobium par reduction electrochimique du NbCl5 en milieu sels fondus a 7000C montre que tous les elements metalliques presents dans la cellule sont corrodes. Dans ces conditions, l'electrolyse ne produit qu'un alliage Ni3Nb et jamais le niobium pur. Pour determiner les effets de NbCl5, nous avons etudie l'oxydation de quelques metaux purs (M = Ni, Cr, Nb, Fe, Ti) et alliages (NSMC, NS21C, NS22S, NS30, INCONEL 600) places dans du NbCl5 gazeux. Pour les metaux purs, cette corrosion est limitee a la formation de dichlorures (M, Nb)Cl2 purs ou melanges. Ni et Cr sont les plus resistants dans cette atmosphere. Les alliages avec le metal M comme composant principal montrent une corrosion bien plus importante que le metal pur. Mais le taux de corrosion est toujours trop faible pour expliquer la grande quantite de NiCl2 qui est formee quand la cellule est alimentee en continu avec NbCl5. Nous etudions maintenant les memes metaux et alliages en milieu sels fondus pour differentes concentration en NbCl5Additional details
Additional titles
- Original title (French)
- Comportement a 700
Publishing Information
- Journal Title
- Materiaux et Techniques
- Journal Volume
- 79
- Journal Issue
- 7-8
- Series
- Mater. Tech.
- Journal Page Range
- 27-34
- ISSN
- 0032-6895
- CODEN
- MATCB
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 23030177
- Subject category
- S36: MATERIALS SCIENCE;
- Descriptors DEI
- ALLOY-NI76CR15FE8; CHROMIUM; CORROSION; IRON; NICKEL; NIOBIUM CHLORIDES; OXIDATION; STEEL-CR17NI12MO3; STEEL-CR18NI10; STEEL-CR18NI10TI; TEMPERATURE RANGE 0400-1000 K; TITANIUM; VAPORS
- Descriptors DEC
- ALLOYS; ALUMINIUM ADDITIONS; AUSTENITIC STEELS; CARBON ADDITIONS; CHEMICAL REACTIONS; CHLORIDES; CHLORINE COMPOUNDS; CHROMIUM ALLOYS; CHROMIUM-NICKEL STEELS; CHROMIUM-NICKEL-MOLYBDENUM STE; CORROSION RESISTANT ALLOYS; CROLOY; ELEMENTS; FLUIDS; GASES; HALIDES; HALOGEN COMPOUNDS; HEAT RESISTING ALLOYS; HIGH ALLOY STEELS; INCONEL ALLOYS; IRON ALLOYS; IRON BASE ALLOYS; METALS; MOLYBDENUM ALLOYS; NICKEL ALLOYS; NICKEL BASE ALLOYS; NIMONIC; NIOBIUM COMPOUNDS; STAINLESS STEELS; STEELS; TEMPERATURE RANGE; TITANIUM ADDITIONS; TRANSITION ELEMENT COMPOUNDS; TRANSITION ELEMENTS