Precautions for using titanium materials

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Titanium is a corrosion-resistant metal, but in certain oxidizing media, as the temperature and concentration of these media change, oxidation can occur rapidly on the surface of titanium, leading to intense spontaneous combustion reactions that result in fire and explosion accidents. Therefore, before using titanium equipment, it is necessary to thoroughly understand the properties of the medium being used, paying special attention to its corrosivity and oxidizing capacity. It is particularly emphasized that titanium must never be exposed to an environment with absolutely no strong oxidizing agents, as this can easily lead to rapid oxidation and intense spontaneous combustion. To date, there have been several similar explosion incidents in the country. To prevent danger to users during use. Based on domestic and international information, the use of titanium equipment in the following media is strictly prohibited; examples are as follows: 1. Fuming nitric acid with a free nitrogen dioxide concentration of over 98% or a content of over 6%. 2. Dry chlorine gas with a moisture content of 0.1~0.3%. 3. Liquid oxygen and certain aqueous solutions with high oxygen partial pressures. (Titanium is shock-sensitive in liquid oxygen; it will catch fire spontaneously at a pressure of 0.35 Mpa at room temperature.) ) 4. Methanol, trichloroethylene, nitrogen tetroxide, molten metal salts, carbon monoxide, uracil, oxygen, bromine vapor, etc. 5. Hydrogen (hydrogen has a hydriding effect on titanium, causing hydrogen embrittlement when titanium absorbs hydrogen. 6. Titanium is not corrosion-resistant in certain media such as hydrofluoric acid, fluorosilicic acid, hydrochloric acid with a concentration higher than 3%, fuming nitric acid, sulfuric acid with a concentration higher than 4%, and unpressurized boiling formic acid. 7. Crevice corrosion tends to occur in chloride solutions. 8. The operating temperature of titanium in sodium hydroxide and other high-concentration alkaline solutions should be ≤93°C. During the operation of the equipment, the rate of change in pressure and temperature must be strictly controlled, with efforts made to avoid sudden changes in these parameters. Furthermore, according to Article 2.7.4 of the \"Regulations for Safety Technical Inspections of Pressure Vessels\" issued by the General Administration of Quality Supervision, Inspection and Quarantine of China, the operating temperature for pure titanium equipment shall not exceed 315°C.