Marine titanium alloys: Present and future

Abstract

CRISM Prometey has pioneered the use of titanium alloys as structural materials for marine facilities. Specialized titanium alloys for ship hulls, marine power systems, and ship engineering are widely used in shipbuilding and other industries. Prometey has created titanium alloys with the yield strength of 785 MPa and technologies of manufacturing large semifinished products: boards with thickness up to 160 mm, sheet billets for stamping, and billet forgings. The 50-year experience of operation with titanium hull structures has demonstrated that pseudo-α alloys are the optimum variant of welded titanium alloys for marine equipment. These alloys as parts of welded structures are characterized by good weldability and adaptability and high corrosion and mechanical resistance in metallurgical works and shipbuilding. Currently, the company is working to improve the yield strength of pseudo-α-class alloys to 950 MPa, as well as developing the ultrastrong titanium alloy for autonomous manned submersibles, allowing the hydrogeological studies and works at depths up to 11 km. Work is in progress on titanium alloys designed for marine equipment operating in extreme conditions of the Arctic offshore.