New Welding Consumables and Practice for Highly Portable Field Repair

摘要

New welding consumables and practice for weld repair and extended service life were investigated. Exothermally assisted arc welding was successfully accomplished with both SMA and self-shielded FCA welding consumables on steels and the optimum range of exothermic additions and welding parameters was determined Metal powder-filled core aluminum wires were produced which, on welding, promote grain refinement in aluminum weld deposits. Grain refinement in aluminum welds is directly related to weldability by a reduction in the susceptibility for solidification cracking and an improvement in weld metal properties. The use of strip-to-wire mill to make metal powder-filled cored wires has demonstrated an effective methodology for making specialty welding consumable wires for the U.S. Army where their use is of low volume but essential to the manufacture or maintenance of special technical assemblies. Special attention has been given to the welding of light metals (Aluminum and magnesium alloys). Aluminum welding metallurgy and practices were reviewed and described in a chapter for the Handbook of Aluminum Metallurgy, Process and Equipment. The weldability of magnesium alloys was investigated because new magnesium alloys are being developed to reduce weight in vehicles. To evaluate the service life of time-dependent alloys (i.e., Superalloys relative to TCP intermetallic phase and aluminum precipitation strengthened alloys) and to determine the acceptability of a weld repair relative to its service life (fatigue), new nondestructive techniques are being developed based on electronic and magnetic property measurements.