Application and selection of titanium alloy valve

Titanium and titanium alloy, light weight, high strength, high yield ratio, non magnetic, biologically inert, and has excellent corrosion resistance. In seawater environment, titanium and Titanium castings almost no corrosion, corrosion resistance is excellent in most chemical medium. At present, with the progress of science and technology and all walks of life to the application of new materials to increase the strength, the necessary products of titanium valve as the medium of various special environment and special fluid delivery system has been used. However, the fluid medium and environmental conditions in different areas and industries are not the same, performance requirements of the material used on different titanium valve. At the same time, because of the different components ofTitanium alloy valveperformance requirements are different, different process, and to reduce the cost of parts needed to use alternative materials and other factors, the material has become one of the technical problems of first consideration must be titanium valve design and manufacturing, and suffer the widespread concern and attention. Industrial pure titanium refers to non titanium alloys with different Fe, C, N, O and other impurities content. Industrial pure titanium can not be heat treated strengthening, molding excellent performance, easy welding and brazing. Titanium alloy with titanium, alloy by adding Al, Sn, Cr, Mo and Mn elements. Titanium alloy usually in annealing state phase classification, divided into alpha, beta and alpha + beta type titanium alloy. The main components of titanium alloy for alloy Ti with Al, Sn, Cr, alpha stable elements, the return of state organization for a solid solution. Titanium alloy can not be strengthened by heat treatment, its strength than the beta and alpha + beta type titanium alloy is low, but keep the high temperature strength and good in 500 ~ 600 ℃ when in use. The welding properties, casting properties, pressure processing performance, stability and no cold brittle good with titanium alloy, disadvantage is the low technology of plastic and the hydrogen embrittlement sensitivity. Titanium alloy is widely used in practice. Casting titanium metal must have fluidity and good processibility, mechanical properties of domestic and foreign typical casting titanium and titanium alloy is shown in table 1. Wrought titanium metal must have good plasticity, mechanical properties of domestic and foreign typical forging of titanium and titanium alloy is shown in table 2.

Great effect on the mechanical properties of O, C and N impurities often exist in titanium to titanium, which can enhance the strength of titanium and reduce its plasticity, the larger N, effect of C is low, the effect of intermediate O. In addition, B, Be and Al elements to improve the impact strength of the larger Ti, Cr, Mo, Mn, Fe, V and Sn on the strength of titanium has little effect. Al is often used as a stable elements of alpha, alpha + beta type titanium alloy and alloy elements, a grain of alloy, improve the recrystallization temperature and phase transition temperature, and a significant strengthening effect, and can reduce the alloy density, increase the elastic modulus. Mo is often used as the stable elements, beta beta alpha + beta type titanium alloy and alloy elements, is not significantly reduces the material plastic case, strengthen the role of the larger, can also improve the fracture toughness, the corrosion resistance of materials, reduce the stress corrosion sensitivity.

Titanium and titanium alloy of high strength, low density and other properties make it widely used in aerospace engineering. Such as various pipeline aircraft on the extensive use of titanium alloy valve, Titanium castingstype relates to the cut-off valve, check valve, needle valve, plug valve, ball valve and butterfly valve. Titanium valve as the key system components conveying fluid control titanium alloy pipe, widely used in chemical engineering. Valve valve with fasteners as important component, is also very important in valve design, manufacture. Implemented in a large PTA project mass production and application. Titanium valve is widely used in chemical industry, but must pay attention to its not suitable for any chemical medium. The hydrofluoric acid, hydrochloric acid, sulfuric acid and phosphoric acid and oxalic acid, formic acid, hot concentrated three chloroacetic acid, three trifluoroacetic acid and strong corrosive aluminum chloride, have severe corrosion effect of titanium and titanium alloy, titanium valve is not suitable for this kind of chemical medium, should pay attention to in use.‍