Delta--ferrite transformations in a Type 316 weld metal

Journal Article · Mon Jan 01 04:00:00 EST 1979 · Weld. J. (Miami); (United States)

OSTI ID:6557228

Lai, J K; Haigh, J R

The effects of stress relief heat treatments on the microstructure of a Type 316 stainless steel weld metal are described for temperatures in the range 538 to 800 C (1000 to 1472 F). In the as-welded condition, the weld deposit contains delta--ferrite and austenite and, during stress relief, the delta--ferrite transforms predominantly to carbides and austenite at 538 to 650 C (1000 to 1202 F) and to chi-phase at 800 C (1472 F). These observations are related to creep crack growth data at 538 and 600 C (1000 and 1112 F) and provide an explanation for the significantly improved ductility caused by heat treating at 800 C (1472 F). Weld metal heat treated at 800 C (1472 F) for 10 h appears to be stabilized against any likely microstructural causes of embrittlement in long term service at up to 650 C (1202 F) and may be treated for design purposes in the same way as base metal steels.

• Research Organization: Central Research Laboratories, Leatherhead, Surrey, England
• OSTI ID: 6557228
• Journal Information: Weld. J. (Miami); (United States), Journal Name: Weld. J. (Miami); (United States) Vol. 58:1; ISSN WEJUA
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
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36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
360102 -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
CARBIDES
CARBON COMPOUNDS
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
CORROSION RESISTANT ALLOYS
CRACKS
CREEP
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
DUCTILITY
EMBRITTLEMENT
FAILURES
FILLER METALS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HEAT TREATMENTS
IRON ALLOYS
IRON BASE ALLOYS
JOINTS
MATERIALS
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
MICROSTRUCTURE
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NUCLEATION
PHASE TRANSFORMATIONS
REACTOR MATERIALS
RUPTURES
STAINLESS STEEL-316
STAINLESS STEELS
STEELS
TENSILE PROPERTIES
WELDED JOINTS