Analysis of effect of temperature gradients on surface-tension phenomena in gas-tungsten-arc welds

Technical Report · Fri Oct 01 04:00:00 EDT 1982

DOI:https://doi.org/10.2172/6725129· OSTI ID:6725129

Lee, H A; Chien, P S.J.

Fluid motion directed by surface tension is considered as a contributor to heat penetration in a weld pool. The potential phenomena at the gas-liquid interface were analyzed, and the dependence of surface motion on temperature in the gas-tungsten-arc (GTA) welding process was examined. An existing heat-transfer model was used and was able to predict weld size to +- 50% of the actual value. A momentum-transfer equation was derived by considering the contribution of Lorentz force. The momentum boundary condition was developed and was able to predict the Marangoni effect. The magnitude of surface-tension-driven force is comparable to the gravitational force on one gram. An empirical approach was proposed to couple heat-transfer and momentum-transfer phenomena. A dimensional analysis identified the pertinent dimensionless groups as Reynolds, Weber, Froude, Peclet, and Power numbers and a dimensionless velocity. A simplified form of the correction was developed by combining dimensionless groups to yield a correlation with the Bond, Prandtl, and modified power numbers. Future experimental work was proposed to test the functionality of the dimensionless groups.

• Research Organization: Massachusetts Inst. of Tech., Oak Ridge, TN (USA). School of Chemical Engineering Practice
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6725129
• Report Number(s): ORNL/MIT-345; ON: DE83001679
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
ARC WELDING
ENERGY TRANSFER
EQUATIONS
FABRICATION
FLUID FLOW
GAS TUNGSTEN-ARC WELDING
HEAT TRANSFER
JOINING
MATHEMATICAL MODELS
MELTING
PHASE TRANSFORMATIONS
SURFACE PROPERTIES
SURFACE TENSION
TEMPERATURE GRADIENTS
WELDING