Bead temperature effects on FCAW heat-affected zone hardness

Journal Article · Wed Nov 01 04:00:00 EST 1995 · Welding Journal

OSTI ID:131641

Kiefer, J H ^[1]

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1. Conoco, Inc., Houston, TX (United States)

Hardness limits for welding procedure qualification are often imposed to lessen the chances of delayed hydrogen cracking during production fabrication. Temper bead techniques have been used by fabricators during these qualifications to improve their chances of success. This practice involves using the heat of additional weld beads to soften the heat-affected zone (HAZ) hardness in the base metal next to the weld where the hardness is the greatest. The technique works under controlled conditions, but the consistency for field use was questionable. This report describes an investigate of the effect of welding parameters, base metal chemical composition, and weld bead placement on HAZ softening. An empirical formula developed from base plate chemical composition, weld cooling time, and temper bead placement can be used to estimate the amount of HAZ tempering. Combined with an appropriate hardness prediction formula, it can help find the welding procedure needed to achieve a desired maximum HAZ hardness, or predict the HAZ hardness of existing welds. Based on the results of the study, bead temperature is not recommended for HAZ hardness control on large scale fabrications.

• OSTI ID: 131641
• Journal Information: Welding Journal, Journal Name: Welding Journal Journal Issue: 11 Vol. 74; ISSN 0043-2296; ISSN WEJUA3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARC WELDING
CARBON STEELS
CRACK PROPAGATION
HARDNESS
HEAT AFFECTED ZONE
USES