voestalpine Böhler Welding has more than 30 years of experience in the production of welding consumables for demanding applications in pressure vessels and furnace tubes construction. Among other products, we offer first-class CrMo and CrMoV welding consumables that meet and often exceed the requirements of the relevant API recommendations, the applicable regulations and the  specifications used in the industry.

They feature excellent toughness at low temperatures, high resistance to tempering embrittlement, creep resistance and all the required mechanical properties. We also provide weld cladding solutions for a wide range of alloys, including innovative single layer and high-speed strip cladding, with proven corrosion resistance and disbonding properties. Last but not least, we offer well-referenced solutions for centrifugal casting tubes, with filler metals matched to the base material grades.

The production of welds on pressure vessels, especially from low-alloy and high-alloy materials, is challenging due to various material sensitivities (e.g. cold, heat and reheat cracking). voestalpine Böhler Welding offers a complete portfolio of welding consumables covering the most demanding requirements from carbon-manganese steels to low-alloy, high-alloy steels and nickel alloys. The Cr-Mo filler materials have low levels of impurities and diffusible hydrogen to meet the API requirements.

Nozzle welds

The conventional process for the nozzle to shell weld is SMAW for the smaller nozzle diameters (SAW is applied when the diameters allow it). Covered electrodes made by voestalpine Böhler Welding are the best compromise between mechanical properties and all positional handling.

Weld overlay

Strip cladding with SAW or ESW processes is selected for the shells and heads. voestalpine Böhler Welding offers solutions for cladding in a single layer and at high speeds, ensuring its customers improvement in production processes.  SMAW, GTAW, GMAW, FCAW and SAW (with wire) processes are used for the weld overlay in the nozzles and for repair. voestalpine Böhler Welding offers a complete portfolio of filler materials suitable for this application (from stainless-steel grades to nickel alloys).

Production of the shell

Depending on the requirements and thickness, the shell can be made from rolled plates or forged rings. The SAW process is used for both longitudinal and circular welds. In particular, the narrow gap submerged arc with tandem technique is used for heavy wall circular welds. voestalpine Böhler Welding offers SAW wires and fluxes that ensure outstanding mechanical properties even at long PWHT and very good slag detachability.

In both of the above-mentioned applications, centrifugally cast tubes are the main elements in the process. The tubes and the respective welded joints have to be able to withstand numerous damage mechanisms, including but not limited to creep/stress ruptures, carburization and fatigue. Being able to balance increased strength, higher creep resistance and greater toughness has been a challenge for the industry.

For decades, the industry has benefited from the introduction of new alloys with various Cr and Ni contents and from the addition of alloying elements (such as Si, Ti, Zr, Nb, Mo, Co, etc.) to create the ability to withstand higher operating temperatures and, at the same time, to reach reasonable creep strength and carburization resistance. Over-alloyed welding consumables compared to the base metal are available in our portfolio. But the matching filler materials for each tube grade are also offered to minimize the difference between the thermal expansion coefficient in the weld joint and the base material enabling a longer life cycle of the welded component.