HIGH DEPOSITION RATE GAS TUNGSTEN ARC (TIG) WELDING OF HIGH STRENGTH STEELS.
Abstract
Reliable procedures were established for high deposition Tig welding of three high strength steels. However, the selection of welding procedures is a function of the metallurgical behavior of each weld metal. Because a postweld quench and temper heat treatment homogenizes most structural variations, the properties of welds made in D-6ac are virtually independent of welding parameters. Although the postweld maraging heat treatment of welds made in 18 Ni (VAR) steel makes the tensile properties independent of welding procedures, the fracture toughness of such welds can vary. Toughness is a function of the amount of grain refinement and thermal cycling achieved in multipass welds. By balancing filler deposition rates and welding heat input, pass size can be adjusted so fracture toughness of welds will be equivalent or superior to conventional Tig welds. The as-welded tensile and impact properties of welds made in HP 9 Ni-4 Co-.20 C steel are very sensitive to welding conditions. Grain refinement and self-tempering must be maximized; yet the amount of ferrite in the microstructure must be minimized. Despite these restraints, high deposition welding procedures will develop weld metal properties equivalent to Tig welding. The high deposition rate Tig-hot wire process should offer significant cost savings to aerospace fabricators. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 15, 1968
- Accession Number
- AD0835225
Entities
People
- Howard R. Miller