The influence of various residual elements on the elevated-temperature properties of austenitic stainless steel welds has been investigated at the Oak Ridge National Laboratory (ORNL). Included in this investigation are the effects of boron, phosphorus, titanium, carbon, sulfur, and silicon. This work is aimed at developing austenitic stainless steel weld materials with enhanced elevated-temperature properties.

The materials investigated include types 308, 316, and 16-8-2 stainless steel weld metals. Processes investigated include shielded metal-arc (SMA), gas tungsten-arc (GTA), and submerged-arc (SA) welding. Early work was done with Types 308 and 316 SMA weld metals, where the greatest enhancement of properties resulted from controlled additions of boron, phosphorus, and titanium to the deposits. Significant improvements in the properties of GTA and SA welds also result from the addition of these residual elements. The optimum residual element compositions were determined to be nominally 0.05Ti-0.04P-0.006B for SMA welds and 0.5Ti-0.04P-0.006B for GTA welds. Submerged-arc welds with 0.2Ti have exhibited improved creep strengths for all three materials.