Low-alloy welding wire designed to help improve weld quality on modified Grade 91 steels

To help improve weld quality on modified Grade 91 steels used in high-temperature, high-pressure applications in the power generation and petroleum industries, Hobart Brothers offers its Tri-Mark® TM-B9 welding wire. This gas-shielded, flux-cored wire offers all-position welding capabilities and matches the base material properties.

The wire meets the requirements of chrome-moly welding, including providing an X-factor of less than 15 PPM. The wire also provides a weld deposit with low diffusible hydrogen content — 0.10 fl. oz. per 3.53 oz. of weld metal — to prevent cracking during the pre- and postweld heat-treat cycles of Grade 91 steels. This feature results in X-ray-quality welds and minimizes downtime for rework, the manufacturer states.

The welding wire features a fast-freezing slag that allows for welding in all positions without concern for slag inclusions, according to the company. It also delivers low spatter levels and arc stability.

The wire has a tensile strength of 116 KSI and yield strength of 96 KSI. It is available in 0.045-in. diameters on 33-lb. spools. It operates with a shielding gas mixture of 75 percent argon and 25 percent CO₂.