Nitrogen and hydrogen pick-up of ST-52-3 weld metal and delayed cracking in hyperbaric GMA welding

Book · Sat Dec 31 04:00:00 EST 1994

OSTI ID:27954

Aune, R; Hoffmeister, H; Huismann, G ^[1]

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1. Univ. der Bundeswehr Hamburg (Germany). Lab. fuer Werkstoffkunde und Schweisstechnik

The pulsed GMA process has been analyzed at pressures from 1 to 16 bar with respect to required pulse parameters for stable droplet transfer and defect free welding of double V TEKKEN test joints. The effects of nitrogen and moisture contaminations of the Ar shielding gas on nitrogen and hydrogen in the weld metal were identified. In accordance with earlier literature, also the pulsed GMA process provides less nitrogen and hydrogen in the weld metal at increased ambient pressure. Consequently, the hydrogen induced cracking is reduced at increasing ambient pressure in such a way that for the present parameters, a water vapor pressure of 20 mbar in the shielding gas may be tolerable at pressures above 2--4 bar.

• OSTI ID: 27954
• Report Number(s): CONF-940230--; ISBN 0-7918-1266-9
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
CHEMICAL COMPOSITION
CRACKS
EXPERIMENTAL DATA
FRACTURE PROPERTIES
GAS METAL-ARC WELDING
HYDROGEN
METALLOGRAPHY
NITROGEN
SAMPLE PREPARATION
SCANNING ELECTRON MICROSCOPY
STEELS
WELDED JOINTS