Published May 1978 | Version v1
Journal article Metadata-only

The relationship between duplex oxidation and structural stability in austenitic stainless steels

Creators

  • 1. Central Electricity Generating Board, Berkeley (UK). Berkeley Nuclear Labs.

Description

Samples of austenitic stainless steels from various sources have been thermally cycled. Many materials exhibited a volume expansion on cooling superimposed on the normal thermal contraction, as a result of an austenite → ferrite phase transformation. Samples of materials which exhibited the ferrite transformationalso show a period of rapid oxidation on re-exposure after cooling during the first autoclave shutdown of an oxidation test. It is proposed that the local volume expansion accompanying the formation of ferrite on cooling disrupts the initial protective oxide scale thereby allowing oxidation to proceed more rapidly. (orig.)

Abstract (German)

Proben nichtrostender austenitischer Staehle verschiedener Herkunft wurden thermischer Wechselbeanspruchung ausgesetzt. Dabei zeigten verschiedene Werkstoffe beim Abkuehlen eine Volumenexpansion, die sich der normalen thermischen Kontraktion ueberlagerte; diese Erscheinung ist einer Phasenumwandlung Austenit → Ferrit zuzuschreiben. Proben von Werkstoffen mit dieser Ferritumwandlung zeigen bei erneuter Beanspruchung im Oxidationstest nach dem Abkuehlen eine Periode rascher Oxidation. Es wird angenommen, dass durch die oertliche Volumenzunahme bei der Ferritbildung waehrend des Kuehlens die urspruenglich schuetzende Oxidschicht aufgerissen wird und die Oxidation daher beschleunigt weitergehen kann. (orig.)

Additional details

Publishing Information

Journal Title
Werkst. Korros.
Journal Volume
29
Journal Issue
5
Series
Werkst. Korros.
Journal Page Range
326-330

INIS

Country of Publication
Germany
Country of Input or Organization
Germany
INIS RN
10420481
Subject category
S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; S36: MATERIALS SCIENCE;
Descriptors DEI
AUSTENITE; AUSTENITIC STEELS; CONTRACTION; COOLING; EXPANSION; FAILURES; FERRITE; LAYERS; MICROSTRUCTURE; OXIDATION; PHASE TRANSFORMATIONS; STABILITY; STAINLESS STEEL-316; STAINLESS STEEL-321; THERMAL CYCLING
Descriptors DEC
ALLOYS; CARBON ADDITIONS; CHEMICAL REACTIONS; CHROMIUM ALLOYS; CHROMIUM STEELS; CHROMIUM-NICKEL STEELS; CORROSION RESISTANT ALLOYS; CRYSTAL STRUCTURE; HEAT RESISTING ALLOYS; IRON ALLOYS; IRON BASE ALLOYS; MOLYBDENUM ALLOYS; NICKEL ALLOYS; STAINLESS STEELS; STEELS; TITANIUM ADDITIONS; TRANSITION ELEMENT ALLOYS