The appearance of titanium welded pipe is very similar to steel, with a density of 4.51 g/cm3, which lacks 60% of steel, and is a low-density metal element in refractory metals.
Titanium is very stable in the air at room temperature. When heated to 400~550℃, it forms a strong oxide film on the surface to avoid further oxidation. Titanium has a strong ability to absorb oxygen, nitrogen and hydrogen. Such gases are very harmful impurities to titanium metal, and even if the content is very small (0.01%~0.005%), it will seriously affect its mechanical function.
The mechanical properties of titanium, commonly known as its mechanical function, are very much related to its purity. High purity titanium has excellent processing function, elongation and cross-section shortening, but low strength, not suitable for collaborative planning data. Industrially pure titanium is rich in impurities, has high strength and plasticity, and is suitable for making planning data.
Application of titanium and its alloys
Dense metal titanium because of the light weight, higher strength than aluminum alloy, can be maintained at high temperatures than aluminum for the high strength and by the aviation industry's high attention. Given that the density of titanium is 57% of steel, its high specific strength (strength/weight ratio or strength/density are called specific strength), so it has a strong corrosion resistance, oxidation resistance and fatigue resistance. 3/4 of titanium alloys are used as planning data represented by aerospace planning alloys, and 1/4 are mainly used as corrosion-resistant alloys.
Titanium alloys can be categorized as low-strength, high-plasticity, medium-strength and high-strength for 200 (low-strength) ~ 1300 (high-strength) MPa, but titanium alloys can generally be considered as high-strength alloys. They are stronger than aluminum alloys, which are considered medium strength, and can fully replace certain types of steel in terms of strength. Some titanium alloys maintain excellent strength at 600°C compared to aluminum alloys, which lose strength rapidly at temperatures above 150°C.
In addition to strength, according to the use can also be divided into heat-resistant, corrosion-resistant, low-temperature and special function titanium alloys, according to the phase composition can be divided into α, α + β and β and nearly α, sub-stable and several other types.
Titanium cannot be a commonly used metal. Titanium itself is extremely active and difficult to dispose of. It is necessary to strictly control the atmosphere in the furnace, and the welding must be carried out in a lazy atmosphere. Titanium metal activity is high, low thermal conductivity, deformation resistance, room temperature plasticity is poor. In the deformation process, not only easy to bond with the mold, but also in the machining of tools and abrasives have a tendency to bond to the surface of the hot machining, which makes the production of standard planning parts produced a large number of waste titanium chips, the so-called residual titanium.
In order to reduce the burden of high-cost formation, on the one hand, the titanium residual treatment process has been carried out, and on the other hand, high-tech technologies such as near-net molding, superplastic molding, fine casting, powder metallurgy, and hot isostatic dispersion joining have been developed. For example, the powder metallurgy products processed by the powder, molding, sintering or hot isostatic pressure solidification method is nearly net into the data utilization rate of up to 80%, not only reduces the data consumption, but also significantly reduces the amount of cutting and processing. Another example is the use of large-scale thin-walled fine casting skills in titanium alloys, so that titanium castings function close to titanium forgings, while the cost decreased by about 50%.
Titanium white paint is mainly used in coatings, plastics, paper, synthetic fibers, printing ink, rubber, enamel and other aspects of other white paint. Ultrafine titanium dioxide and water and organic solvents composed of titanium sol has become an independent new species, used in cosmetics, lens exterior finishing agents, inks and coatings to increase the agent, the scope of its application is still expanding. Titanium iron (TiFe) made from ilmenite concentrate is a deoxidizer and stabilizer used in the manufacture of stainless steel. Titanium iron hydrogen storage anode in the production of hydrogen storage batteries and rare earth hydrogen storage data have their own advantages, while the cost is relatively low, in hydrogen storage, transportation, catalytic, fuel cells, etc. will compete with rare earth.
