Welding Division - Superalloys
Nickel superalloys have evolved from first generation single phase austenitic alloys such as IN600 and IN625, through second generation two phase heat-treatable alloys such as IN718 and Nimonic 80A. The improvements to the high temperature properties of these alloys has continued to the current so-called fifth generation of advanced heat-treatable superalloys.
Many of these alloys are used in the precision investment cast form with single crystal, directional crystal and fine poly crystal structures.
Such materials have to be welded for a number of reasons, including casting defect repair, machining error defects, in-service wear, z-notch hard facing and attaching other fittings. The major problem, however, is the susceptibility to micro fissuring and hot-cracking that these alloys have when welded.
An economic alternative to scrapping very expensive superalloy components is to use advanced GTAW technology that has been developed for this purpose by VBC Group Ltd.
The VBC InterPulse welding power source is a heat-management, constricted-arc machine that helps to minimise local residual stress and thermal damage when micro fusing filler metal to the defective component.
Many successful welding procedures have now been established for welding complex nickel alloys containing high volume fractions of gamma prime. Although developed especially for use in the hot section of flying gas turbine engines, the VBC InterPulse welding power source is becoming widely used for industrial turbine NGV salvage welding by foundries, turbine builders and the power utilities.
The VBC InterPulse advanced welding power source is very shop floor friendly, effective and versatile. There is no need for traditional expensive capital laser or electron beam plant.
The VBC InterPulse is also preferred for titanium alloy fabrication, where it produces exceptional quality welds, essentially free from inclusions, porosity and oxygen absorption and alpha case problems. It can obviate the use of awkward, cumbersome and expensive welding chambers. The power source is also used to fabricate high strength structural engineering steels to nuclear standards, where minimum contamination from inclusions, residuals and tramp elements and associated high toughness is essential.
The pioneering advanced GTAW technology of the VBC InterPulse uses leading-edge electronics, welding engineering and applied metallurgy and is a significant benefit for aerospace and specialised engineering metal joining applications.
VBC Group Ltd created this unique machine in collaboration with blue chip turbine businesses to solve their specific welding problems and builds this equipment in one of its UK factories. Welder training is provided together with welding procedure development and site demonstration. Seminars and teaching presentations are associated activities of VBC InterPulse sales.
This advanced welding power source can pay for itself in a few days and it has enabled companies to totally rethink and revise their metal joining attitudes and activities.
