A detailed explanation of common structural titanium tube material types

Titanium has a density of 4.5g/cm³, a melting point of 1668℃, and a linear expansion coefficient of 8.4 × 10^-6 /℃ at 20℃. Its thermal conductivity is 16.329W/(m × k).Titanium and titanium alloys have outstanding corrosion resistance. In oxidizing, neutral and chloride ion media, their corrosion resistance is superior to that of stainless steel. Pure titanium is a silvery-white metal. Above 882℃, it has a body-centered cubic structure, known as β titanium. Below this temperature, it has a closely arranged hexagonal structure, known as α titanium. The allotropy transformation temperature varies with the different contents of alloying elements and impurities in titanium. Titanium has a strong affinity for oxygen and can even rapidly form a stable and fine oxide film at room temperature. Due to the presence of this film, titanium has outstanding corrosion resistance. The dissolved oxygen and nitrogen in titanium can significantly strengthen it, but its plasticity decreases significantly. Hydrogen can embrittlement titanium and titanium alloys. Industrial pure titanium is widely used in the chemical industry due to its advantages such as good plasticity, corrosion resistance, good weldability and easy formability.

Many variable factors indicate the characteristics of corrosive media, namely the chemical products and their concentrations, atmospheric conditions, temperatures, and time. Therefore, if the exact properties of the medium are unknown, it is difficult to use and select materials. However, the following can serve as a selection guide:

Type 304 is a widely used material. It can withstand the common rust in construction, resist the corrosion of food processing media (but high-temperature conditions rich in concentrated acids and chloride components can cause corrosion), and resist organic compounds, dyes and a wide variety of inorganic compounds.

Type 304L (low-carbon) has good resistance to nitric acid and can be used with medium-temperature and medium-concentration sulfuric acid. It is widely used as a liquid gas storage tank, as a low-temperature equipment (304N), utensils, other consumer products, kitchen equipment, hospital equipment, transportation tools, and wastewater treatment equipment.

Type 316 contains slightly more nickel than type 304 and 2% to 3% molybdenum. It has better corrosion resistance than type 304, especially in chloride media that tend to cause pitting corrosion. Model 316 has been used as a sulfite pulp machine because it is resistant to sulfuric acid compounds. Moreover, its application has expanded to handle many chemical products in the processing industry.

Type 317 is rich in 3% to 4% molybdenum (which is also a relatively high level obtained in this series), and contains more chromium than type 316, thus having a higher resistance to pitting and crevice corrosion.

Type 430 has a lower alloy content than type 304 and is used for high-polishing embellishment in warm atmospheres. It can also be used in nitric acid and food processing equipment. The 410 type has the lowest alloy content among the three commonly used industrial titanium plates and is suitable for high-load-bearing components that require a combination of strength and corrosion resistance, such as robust parts. Model 410 is corrosion-resistant in warm atmospheres, water vapor and many gentle chemical product media.

Type 2205 is superior to Type 304 and type 316 due to its layout, as it has a high resistance to chloride stress corrosion cracks.