Titanium 6Al-4V/Grade 5 (UNS R56400) is the most widely used titanium grade. It is a two phase alpha+beta titanium alloy, with aluminum as the alpha stabilizer and vanadium as the beta stabilizer. This high-strength alloy can be used at cryogenic temperatures up to about 800°F (427°C). Titanium 6Al-4V alloy is principally used in the annealed condition.

As in other titanium alloys, Titanium 6Al-4V corrosion resistance is based on the existence of a consistent and continuous oxide layer which is formed spontaneously upon exposure to oxygen. It has excellent resistance to corrosion in seawater making it a good choice for use in offshore and subsea oil & gas operations where seawater corrosion and weight are concerns.

Titanium 6Al-4V is resistant to general corrosion but may be quickly attacked by environments that cause breakdown of the protective oxide layer including hydrofluoric (HF), hydrochloric (HCl), sulphuric and phosphoric acids. Titanium 6Al-4V resists attack by pure hydrocarbons, and most chlorinated and fluorinated hydrocarbons provided that water has not caused formation of small amounts of hydrochloric and hydrofluoric acids.

Titanium 6Al-4V is produced by primary melting using vacuum arc (VAR), electron beam (EB), or plasma arc hearth melting (PAM). Refining is achieved by vacuum arc remelting.

Applications
Titanium 6Al-4V is used in applications where high strength, light weight and corrosion resistance are important. Potential applications include shafts and pressure housings, subsea wellhead and riser components, ROV components, seal rings, and other critical forgings requiring high strength-to-weight ratios. This alloy has also been used in cycling and motorsport applications to reduce weight/size of components.