The chemical, physical, and mechanical properties of the titanium tube used for the GR1 exhaust.

1, the density of titanium metal is 4.51g/cm3, higher than aluminum and lower than steel, copper, nickel, but the specific strength is located in the first metal. The melting point of titanium 1660 ± 10 ℃. Boiling point 3287 ℃. The valence +2, +3 and +4. It has good corrosion resistance and is not affected by the atmosphere and seawater. At room temperature, it will not be corroded by dilute hydrochloric acid, dilute sulfuric acid, nitric acid or dilute alkali solution; only hydrofluoric acid, hot concentrated hydrochloric acid and concentrated sulfuric acid can work.

2,Titanium metal dust is explosive and will burn and explode when it meets heat, open flame or chemical reaction. Its powder chemical activity is very high, in the air can be spontaneous combustion. Titanium metal can not only burn in air, but also in carbon dioxide or nitrogen. It is easy to combine with halogen, oxygen, sulfur and nitrogen at high temperature. When titanium burns, use dry powder and dry sand to extinguish the fire. Strictly prohibit water, foam, carbon dioxide extinguishing. High heat or intense combustion, water extinguishing may cause an explosion.

3, titanium activity is very large, not only in the dissolved state, even in the solid state above 400 ℃, but also easily contaminated by water, air, oil and oxides, absorption of oxygen, nitrogen, hydrogen, carbon and so on. Thus reducing the plasticity and toughness of welded joints and cracks. Iron pollution on titanium is mainly in the welding and heating process to form brittle titanium-iron compounds, reducing the mechanical properties of welds and corrosion resistance; in the role of corrosive media, surface iron particles will cause pitting and hydrogen embrittlement.

4, the coefficient of linear expansion of titanium is about 2/3 of carbon steel, equivalent to 50% of stainless steel. Titanium's thermal conductivity is 4.5 times smaller than that of carbon steel and lower than that of stainless steel.

5, titanium has obvious resilience, its resilience is stainless steel when cold molding 2 to 3 times. And stainless steel as easy to stick. Titanium's tensile strength decreases as the temperature rises. When the temperature reaches 250 degrees its tensile strength is only 50% of room temperature.

6, industrial pure titanium plasticity and temperature has a special relationship, room temperature to 200. C, the relative elongation of titanium increased, and then continue to raise the temperature began to decline. In 450 ~ 500 when the relative elongation reached a minimum and then rose significantly. Therefore, the use of temperature does not exceed 350 ℃.