Gr4 titanium and titanium alloys have a density of only 4.51, which is smaller than steel and only half the weight of steel, but their strength is about the same as common carbon steel. Titanium is attributed to thermodynamically unstable metal, very active, titanium metal can be generated with the air natural oxide film (titanium dioxide), this layer of stable, strong adhesion, protective exceptionally good oxide film, determines the corrosion resistance of titanium, and thus titanium has excellent corrosion resistance, and secondly, light weight, high tensile strength, good mechanical properties of titanium alloys is another excellent feature.
Titanium alloy according to the use can be divided into: corrosion-resistant titanium alloy, structural titanium alloy, heat-resistant titanium alloy gold, low temperature titanium alloy.
1. It can be distinguished from the color. Titanium is a little dark, through a kind of cold color, feel cool, titanium is a little darker than steel. Steel is white, miserable white kind. The two colors can be seen very clearly.
2. There can be distinguished by chemical methods, that is, with nitric acid soak. Titanium does not react, stainless steel will react strongly once put down. Pure titanium and titanium alloy distinction is difficult to see from the outside.
3. Titanium can be scratched on the tiles to gray-black marks, but stainless steel can not be scratched to the mark.
4. Titanium corrosion resistance is good: below 550 ℃ titanium alloy profile is easy to form a dense oxide film, so it is not easy to be further oxidized, on the night air, seawater, steam, and some acids, alkalis, soft media have a high loss of corrosion resistance.
5. Titanium thermal strength: titanium alloy melting point of 1660 ° C, higher than iron, has a high thermal strength, can be below 550 ° C things, while at the same time in the low temperature showed good toughness.
6. Titanium processing is difficult: welding, plating, cold stretching is very difficult. Welding, plating must be in a vacuum or in a situation filled with inert gas (vacuum ion plating)
Titanium alloy is widely used in various fields because of its high strength, good corrosion resistance, heat resistance and other characteristics.
The density of titanium alloy is generally around 4.51g/cm3, only 60% of steel, the density of pure titanium is only close to the density of ordinary steel, some high-strength titanium alloy exceeds the strength of many alloy structural steel. Therefore, the specific strength of titanium alloys (strength / density) is much greater than other metal structural materials, see Table 7-1, can be produced unit of high strength, good rigidity, lightweight parts. Aircraft engine components, skeleton, skin, fasteners and landing gear, etc. are using titanium alloys.
304 is a general-purpose stainless steel that is widely used to make equipment and machine parts that require good all-around performance (corrosion resistance and formability). In order to maintain the corrosion resistance inherent in stainless steel, the steel must contain more than 18% chromium and more than 8% nickel.
With a density of 7.93 g/cm3, it is also called 18/8 stainless steel in the industry. Resistant to high temperatures up to 800 degrees Celsius, characterized by good processability and high toughness, it is widely used in the industrial and furniture decoration industry and the food and medical industry.
