Narrow groove gas tungsten arc welding of ASTM A508 Class 4 steel for improved toughness properties

Technical Report · Tue Apr 01 04:00:00 EST 1997

DOI:https://doi.org/10.2172/319838· OSTI ID:319838

Penik, Jr, M A ^[1]

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1. Rensselaer Polytechnic Inst., Troy, NY (United States)

Welding of heavy section steel has traditionally used the automatic submerged arc welding (ASAW) process because of the high deposition rates achievable. However, the properties, particularly fracture toughness, of the weld are often inferior when compared to base material. This project evaluated the use of narrow groove gas tungsten arc welding (GTAW) to improve weld material properties. The welding procedures were developed for ASTM A508 Class 4 base material using a 1% Ni filler material complying to AWS Specification A.23-90-EF3-F3-N. A narrow groove joint preparation was used in conjunction with the GTAW process so competitive fabrication rates could be achieved when compared to the ASAW process. Weld procedures were developed to refine weld substructure to achieve better mechanical properties. Two heaters of weld wire were used to examine the effects of minor filler metal chemistry differences on weld mechanical properties. Extensive metallographic evaluations showed excellent weld quality with a refined microstructure. Chemical analysis of the weld metal showed minimal weld dilution by the base metal. Mechanical testing included bend and tensile tests to ensure weld quality and strength. A Charpy impact energy curve versus temperature and fracture toughness curve versus temperature were developed for each weld wire heat. Results of fracture toughness and Charpy impact testing indicated an improved transition temperature closer to that of the base material properties.

• Research Organization: Knolls Atomic Power Lab., Schenectady, NY (United States)
• Sponsoring Organization: USDOE Assistant Secretary for Nuclear Energy, Washington, DC (United States)
• DOE Contract Number: AC12-76SN00052
• OSTI ID: 319838
• Report Number(s): KAPL-P--000158; K--97036; ON: DE99001875
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHARPY TEST
EXPERIMENTAL DATA
FILLER METALS
FRACTURE PROPERTIES
GAS TUNGSTEN-ARC WELDING
METALLOGRAPHY
STEEL-ASTM-A508
TENSILE PROPERTIES