Characterization of Tig Welds in 12-5-3 Maraging Steel Plate with Application of a New Scaling Method for K Sub Ic Plasticity Corrections

摘要

This report is concerned with fabricating and optimizing weld joints in the 12-5-3 maraging steel. Three weld-wire compositions, two TIG welding processes, and two heat-treating sequences were compared in all possible combinations. Welds and weld repairs were compared in tensile, impact, fracture-toughness, and metallographic evaluations. Various comparisons are presented in tables and graphs. These data show that the slightly increased yield strength obtained through the Big TIG welding process is more than offset by the reduced toughness K sub Ic values, obtained from the three-point bend test, showed slight advantages in using a weld wire with a lower percentage of titanium and in welding the plate in the aged condition. However, multiple weld repairs may cause as much as a 26-percent decrease in weld toughness. The greatest reduction in toughness was found in the plates that had three aging cycles: one before welding, one after welding, and the third after welding repairs had been made. (Author)