Welding Behavior of Free Machining Stainless Steel

Journal Article · Mon Jul 24 04:00:00 EDT 2000 · Welding Journal Research Supplement

OSTI ID:759979

BROOKS, JOHN A ^[1]; ROBINO, CHARLES V; HEADLEY, THOMAS J; MICHAEL, JOSEPH R

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1. Sandia National Laboratories

The weld solidification and cracking behavior of sulfur bearing free machining austenitic stainless steel was investigated for both gas-tungsten arc (GTA) and pulsed laser beam weld processes. The GTA weld solidification was consistent with those predicted with existing solidification diagrams and the cracking response was controlled primarily by solidification mode. The solidification behavior of the pulsed laser welds was complex, and often contained regions of primary ferrite and primary austenite solidification, although in all cases the welds were found to be completely austenite at room temperature. Electron backscattered diffraction (EBSD) pattern analysis indicated that the nature of the base metal at the time of solidification plays a primary role in initial solidification. The solid state transformation of austenite to ferrite at the fusion zone boundary, and ferrite to austenite on cooling may both be massive in nature. A range of alloy compositions that exhibited good resistance to solidification cracking and was compatible with both welding processes was identified. The compositional range is bounded by laser weldability at lower Cr{sub eq}/Ni{sub eq} ratios and by the GTA weldability at higher ratios. It was found with both processes that the limiting ratios were somewhat dependent upon sulfur content.

• Research Organization: Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 759979
• Report Number(s): SAND2000-1800J
• Journal Information: Welding Journal Research Supplement, Journal Name: Welding Journal Research Supplement
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AUSTENITE
CRACK PROPAGATION
FERRITE
GAS TUNGSTEN-ARC WELDING
LASER WELDING
PHASE TRANSFORMATIONS
SOLIDIFICATION
STAINLESS STEELS
SULFUR CONTENT
WELDABILITY
WELDED JOINTS