Penetration in GTA welding

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6737188

Heiple, C R; Burgardt, P

The size and shape of the weld bead produced in GTA welding depends on the magnitude and distribution of the energy incident on the workpiece surfaces as well as the dissipation of that energy in the workpiece. The input energy is largely controllable through the welding parameters selected, however the dissipation of that energy in the workpiece is less subject to control. Changes in energy dissipation can produce large changes in weld shape or penetration. Heat transport away from the weld pool is almost entirely by conduction, but heat transport in the weld pool is more complicated. Heat conduction through the liquid is an important component, but heat transport by convection (mass transport) is often the dominant mechanism. Convective heat transport is directional and changes the weld pool shape from that produced by conduction alone. Surface tension gradients are often the dominant forces driving fluid flow in GTA weld pools. These gradients are sensitive functions of weld pool chemistry and the energy input distribution to the weld. Experimental and theoretical work conducted primarily in the past decade has greatly enhanced our understanding of weld pool fluid flow, the forces which drive it, and its effects on weld pool shape. This work is reviewed here. While less common, changes in energy dissipation through the unmelted portion of the workpiece can also affect fusion zone shape or penetration. These effects are also described. 41 refs., 9 figs.

• Research Organization: EG and G Rocky Flats, Inc., Golden, CO (United States)
• Sponsoring Organization: DOE/DP
• DOE Contract Number: AC04-76DP03533
• OSTI ID: 6737188
• Report Number(s): RFP-4390; CONF-901008-1; ON: DE90008971
• Resource Relation: Conference: Fall meeting of the Minerals, Metals and Materials Society on physical metallurgy and materials in conjunction with materials week and the material applications and services exposition, Detroit, MI (USA), 7-11 Oct 1990
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GAS TUNGSTEN-ARC WELDING
HEAT FLOW
WELDED JOINTS
DEPTH
ELECTRON BEAM WELDING
FLUID FLOW
STAINLESS STEEL-304
SURFACE TENSION
TEMPERATURE GRADIENTS
WELDABILITY
ALLOYS
ARC WELDING
AUSTENITIC STEELS
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
CORROSION RESISTANT ALLOYS
DIMENSIONS
FABRICATION
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HIGH ALLOY STEELS
IRON ALLOYS
IRON BASE ALLOYS
JOINING
JOINTS
MATERIALS
NICKEL ALLOYS
STAINLESS STEELS
STEEL-CR19NI10
STEELS
SURFACE PROPERTIES
WELDING
360101* - Metals & Alloys- Preparation & Fabrication