How to distinguish titanium materials? What is the difference between TA1 and TA2? And what is the difference between TC4 and these? (1) Titanium in air and oxidizing, neutral aqueous medium, its surface is easy to produce a dense titanium oxide passivation film, which makes the electrode potential of titanium significantly positive, and greatly improves the thermodynamic stability. The degree of chemical stability improvement after metal passivation is expressed by the passivation coefficient, which is 0.18 for iron, 0.37 for nickel, 0.49 for molybdenum, 0.74 for chromium, 0.82 for aluminum, and 2.44 for titanium. Titanium has much better corrosion resistance than stainless steel, aluminum, etc. in many media. (The mobile container also utilizes the characteristics of titanium’s light specific gravity and high specific strength) (2) Titanium does not have the problem of low temperature brittleness like ferritic steel. Titanium can be used as a low temperature container with a temperature as low as -269 degrees, but because austenitic stainless steel, aluminum, copper, etc. can also be used as low temperature containers, And it is cheaper than titanium, so titanium is rarely used in low-temperature stationary containers. In aviation and aerospace, titanium is used as a mobile cryogenic container, which is mainly due to the high specific strength and light weight of titanium. (3) In the chloride-containing medium such as seawater and salt water, carbon steel, low-alloy steel, general stainless steel, and aluminum have poor corrosion resistance, while titanium has unique and excellent corrosion resistance, and about 50% of titanium containers are used. Corrosion resistant to chlorine-containing media. (4) Since the corrosion resistance of titanium is due to the surface oxide film, general industrial pure titanium and titanium alloys are not resistant to corrosion in strong reducing media such as high temperature hydrochloric acid. Ti-32Mo is resistant to hydrochloric acid corrosion, but its plasticity and process properties are poor. (5) Under certain conditions, the media such as fuming nitric acid, dry chlorine, methanol, trichloroethylene, liquid nitrous oxide, molten metal salt, carbon tetrachloride, etc. of titanium may cause combustion, explosion or stress corrosion, which may cause the titanium container to burn. If a vicious accident occurs, titanium containers should be avoided or used with caution for these media. (6) Titanium will burn in pure oxygen with a temperature exceeding 500 degrees or air with a temperature exceeding 1200 degrees, so the titanium container should not be exposed to open flames in the presence of air and oxygen to avoid burning of the titanium container. (7) The impact toughness assessment is generally not required for titanium materials and titanium containers. (8) There are two main types of titanium uses. One is for supersonic aircraft in aviation. Mainly use its high specific strength. The main grade is Ti-6Al-4V, and the other is used in civil industry, mainly for its excellent corrosion resistance, and the main grade is industrial pure titanium. More than 90% of the titanium in my country is used in the civil industry, and about 3/4 of the titanium used in the civil industry is used in containers (including heat exchangers). Therefore, titanium used in containers in my country occupies a pivotal position in the titanium industry. Determination of Titanium for Containers