Welding of helium-doped austenitic and ferritic stainless steels

Conference · Sun Jan 01 00:00:00 EST 1989

OSTI ID:6302004

Lin, H T; Grossbeck, M L; Goods, S H; Chin, B A

Helium was uniformly implanted into type 316 stainless steel and Sandvik HT-9 (12Cr-1MoVW) to levels of 0.18 to 256 appm and 0.3 to 1 appm, respectively, using the ''tritium trick'' technique. Bead-on-plate welds were then produced under fully constrained conditions using the gas tungsten arc (GTA) process. For 316 stainless steel, catastrophic intergranular fracture occurred in the heat-affected zone (HAZ) of welds with helium levels equal to or greater than 2.5 appm. Brittle cracking along the central line of the fusion zone was also observed for the welds containing 105 and 256 appm He. For HT-9, intergranular cracking occurred in the HAZ along prior-austenite grain boundaries of welds containing 1 appm He. Electron microscopy observations showed that the cracking in the HAZ originated from the growth and coalescence of grain boundary helium bubbles and that the fusion zone cracking resulted from the growth of helium at dendrite interfaces. Results of this study indicate that the use of conventional fusion welding techniques to repair irradiation-degraded materials containing even small amounts of helium may be difficult. 8 refs., 3 figs.

• Research Organization: Auburn Univ., AL (USA)
• DOE Contract Number: FG05-86ER52139
• OSTI ID: 6302004
• Report Number(s): CONF-8905118-6; ON: DE89012523
• Resource Relation: Conference: 2. international conference on trends in welding research, Gatlinburg, TN, USA, 15 May 1989; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
22 GENERAL STUDIES OF NUCLEAR REACTORS
AUSTENITIC STEELS
WELDABILITY
FERRITIC STEELS
CRACKS
DOPED MATERIALS
GRAIN BOUNDARIES
HEAT AFFECTED ZONE
HELIUM
MICROSTRUCTURE
RADIATION EFFECTS
ALLOYS
CRYSTAL STRUCTURE
ELEMENTS
FLUIDS
GASES
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
NONMETALS
RARE GASES
STEELS
ZONES
360101* - Metals & Alloys- Preparation & Fabrication
360102 - Metals & Alloys- Structure & Phase Studies
360103 - Metals & Alloys- Mechanical Properties
360106 - Metals & Alloys- Radiation Effects
220200 - Nuclear Reactor Technology- Components & Accessories