Gradient structure formation in titanium alloys using thermohydrogen treatment technology

Abstract

This paper shows the possibility of creating a “linear gradient” structure, which varies from finely dispersed globular grains to coarse lamellar ones over the cross section of a 13-mm semi-finished product of VT6 alloy, using the thermohydrogen treatment method. The formation of the oxide layer and the depth of oxygen penetration were studied depending on the heating temperature and duration of treatment. The oxide stability was assessed during subsequent annealing in vacuum. It was established that the only oxide film which provides protection from hydrogen penetration during hydrogenous annealing at 800 ° C, was formed during heat treatment at 900°C for 4 hours.