Investigation of Weld Pool Structure and Property Control in Pulsed Arc Welding.
Abstract
Pulsed current gas tungsten arc welds made in Fe-26Ni alloy and AISI 321 stainless steel were dimensionally and structurally analyzed. Weld pool kinetics, weld surface ripple formation and weld solidification structure were studied using high speed motion pictures, conventional and scanning electron metallography, and x-ray dispersive analysis. Varestraint tests were performed on AISI 321 and 316 stainless steel sheets to study the effects of grain refinement on the properties of the weld metal and its hot cracking tendency. A two-dimensional heat flow computer model, utilizing an explicit finite difference technique, was developed to predict temperature fields, thermal gradients, the solidus and the liquidus movement and weld pool size and shape at anytime during the course of the welding operation. Results indicate pulsed arc welding process can be manipulated to influence mixing in the weld pool, grain morphology and size in the solidified weld metal and its properties, i.e., hot cracking tendency. Computer simulations of the heat flow can provide accurate predictions of the thermal regime occurring at and around the weld pool during welding. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 04, 1981
- Accession Number
- ADA097392
Entities
People
- G. G. Lessmann
- G. M. Ecer
- H. D. Brody