Processing of ASTM grade 12 titanium alloy and its mechanical and corrosion-resistant properties

A 5 t ingot of ASTM G12 titanium alloy (Ti-0.8Ni-0.3Mo) was melted, and the plates, sheets, coils, bars and thin-wall seam-welded tubes were manufactured. The processability of G12 alloy has proved almost similar to that of commercially pure titanium grades. It has been clarified that G12 alloy had several advantages in the mechanical property compared with titanium alloys G7 and G3; (1) higher strength at elevated temperatures which leads to higher maximum allowable stress in materials design, (2) larger Young's Modulus and (3) higher fatigue strength. The crevice corrosion tests for G12 alloy as well as G7 and G2 alloys have revealed that G12 alloy was quite superior to G2 and was close to G7 in the resistance to crevice corrosion in hot chloride solutions. It can be expected that the industrial application of G12 alloy will increase owing to its attractive characteristics. (author)