Increasing the strength of the deposits of titanium alloys using rods process by microarc oxidation

Abstract

Deposition of a layer of a very hard metal on the surface of components is an efficient method of increasing the service life of structures made of titanium alloys and working in the sea or other corrosive media in abrasion conditions. The material for the surfacing wire is in most cases PT-7 M alloy enriched with oxygen as a result of thermal oxidation. The method studied, to replace thermal oxidation – microarc oxidation, is based on anodizing in electrolyte solutions of high potentials causing microplasma breakdown on the anode. The experiments confirm the promising nature of using microarc oxidation. The metal deposited by argon-arc non-consumable electrode welding with filler rods made of VT6sv alloy was treated by microarc oxidation, and the structure, quality and hardness satisfy the technical requirements. The application of microarc oxidation in contrast to thermal oxidation does not increase the hydrogen content of the wire so that it is not necessary to carry out vacuum degassing together with quenching in water nor subsequent mechanical dressing, and productivity is higher.

Keywords:

• Life of titanium alloys
• corrosive environments
• thermal oxidation
• microarc oxidation
• vacuum degassing

Notes

Selected from Svarochnoe Proizvodstvo 2017(3) 8–13