Effect of rapid solidification on stainless steel weld metal microstructures and its implications on the Schaeffler diagram

Journal Article · Thu Oct 01 04:00:00 EDT 1987 · Welding Research Supplement; (United States)

OSTI ID:7284338

David, S A; Vitek, J M; Hebble, T L ^[1]

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1. Oak Ridge National Lab., TN (United States)

An investigation was carried out to determine the effect of rapid solidification on the weld metal microstructure of austenitic stainless steels and its implication on the ferrite constitution diagram. A wide variety of stainless steels were laser beam welded at different welding speeds and laser power levels. The results indicate that both weld pool cooling rate and the postsolidification solid-state cooling rates have a profound effect on the microstructures. For the steels investigated, the microstructures ranged from duplex austenite ([gamma]) + ferritic ([sigma]) to fully austenitic or fully ferritic. These microstructures were found to be sensitive to both cooling rates and composition. The observed results are rationalized based on rapid solidification theory. Observations of this investigation indicate that solidification rates and postsolidification cooling rates have a profound effect on the observed microstructures, thus making it impossible to predict the microstructures of rapidly cooled weld metal from the conventional constitution diagrams. The influence of the observations made in this investigation on the Schaeffler diagram is demonstrated, and possible corrections to the constitution diagram incorporating the cooling rate effects are proposed. 23 refs., 17 figs., 3 tabs.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 7284338
• Journal Information: Welding Research Supplement; (United States), Journal Name: Welding Research Supplement; (United States); ISSN 0096-7629; ISSN WERSA3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
AUSTENITIC STEELS
CRYSTAL-PHASE TRANSFORMATIONS
FABRICATION
HEATING RATE
IRON ALLOYS
IRON BASE ALLOYS
JOINING
JOINTS
LASER WELDING
MICROSTRUCTURE
PHASE TRANSFORMATIONS
SOLIDIFICATION
STEELS
WELDED JOINTS
WELDING