During gas metal arc welding the metal within the heat affected zone undergoes a significant thermal transient which can result in changes of the microstructure of the material. Such changes can significantly affect the strength, ductility and resistance to corrosion of the material in this area. The object of this study was to develop and verify a model of the gas metal arc process which would predict the thermal transient such that the mechanical and metallurgical properties of the final base metal could be predicted. The equation of heat flow in two dimensions was modified by inclusion of terms to account for radiation and convection heat loss. In addition, the fact that material properties are a function of temperature was included. The resulting equation was highly nonlinear, but successfully approximated through use of finite difference approximations. The interior boundary of the temperature field was the boundary of the molten weld for each set of welding conditions. An empirical correlation was developed, therefore, to predict the size of the weld pool as a function of welding conditions. The model was verified by actually measuring the temperatures with thermocouples during welding. The predicted and measured temperatures were compared and found to be in excellent agreement whenever the weld bead was truly two dimensional. Peak temperatures were predicted within an accuracy of 5% or approximately 132 deg F.

  • Corporate Authors:

    Massachusetts Institute of Technology

    Department of Ocean Engineering, 77 Massachusetts Avenue
    Cambridge, MA  United States  02139
  • Authors:
    • Lipfert, R H
  • Publication Date: 1972-9

Subject/Index Terms

Filing Info

  • Accession Number: 00044157
  • Record Type: Publication
  • Source Agency: Massachusetts Institute of Technology
  • Files: TRIS
  • Created Date: May 11 1973 12:00AM