Corrosion resistance data of industrially pure titanium

Commercially pure titanium: α-phase titanium that contains certain amounts of impurities such as oxygen, nitrogen, carbon, silicon, iron, and other elements. It possesses excellent stamping properties and good welding properties, is insensitive to heat treatment and microstructure types, and maintains a certain strength under satisfactory plasticity conditions. 　　Industrial pure titanium is graded according to the content of impurity elements. Its strength mainly depends on the contents of interstitial elements oxygen and nitrogen. It has high corrosion resistance in seawater, but lower resistance in inorganic acids. It is generally used to manufacture various sheet metal parts or forgings that operate at temperatures ranging from -253 to 350°C and are subject to moderate stress; it can also be used to produce rivet wire and pipes.

2# lthlycyj: Dear experts upstairs, I’m wondering what the corrosion rate of industrial pure titanium is in carbon dioxide? What if the pressure is 19 kilograms and the temperature is 300 degrees?

Titanium is a metal with a strong tendency to form a passive layer; it can rapidly develop a stable oxidizing protective film in air as well as in oxidizing or neutral aqueous solutions. Even if this film is damaged for some reason, it can recover automatically quite quickly. Therefore, titanium exhibits excellent corrosion resistance in oxidative and neutral media. Due to titanium’s excellent passivation properties, in many cases when in contact with dissimilar metals, it does not accelerate corrosion; rather, it may accelerate the corrosion of those dissimilar metals. In low-concentration non-oxidizing acids, when Pb, Sn, Cu, or Monel alloy are brought into contact with titanium to form a cell, the corrosion of these materials accelerates, while titanium remains unaffected. In hydrochloric acid, when titanium comes into contact with low-carbon steel, the formation of new hydrogen on the titanium surface destroys its oxide film, resulting not only in hydrogen embrittlement of titanium but also an accelerated corrosion of it; this is likely due to titanium’s high reactivity toward hydrogen. The iron content in titanium affects its corrosion resistance in certain media. In addition to issues related to the raw materials, an increase in iron content is often caused by iron contamination from welding processes, which leads to higher iron levels in certain areas of the weld seam; as a result, corrosion occurs in a non-uniform manner. When using iron components to support titanium equipment, iron contamination on the iron-titanium contact surface is almost inevitable, and corrosion accelerates in the areas affected by this iron contamination, especially in the presence of hydrogen. When the titanium oxide film on the surface is mechanically damaged, hydrogen penetrates into the metal; depending on conditions such as temperature and pressure, hydrogen diffuses accordingly, causing titanium to develop hydrogen embrittlement to varying degrees. Therefore, when using titanium in systems at moderate temperatures and pressures with hydrogen, surface iron contamination must be avoided. Under normal conditions, titanium does not suffer from pitting corrosion. Titanium also possesses corrosion-fatigue stability. Titanium exhibits good resistance to crevice corrosion, especially Ti-0.3Mo-0.8Ni and Ti-0.2Pd alloys; therefore, these alloys are widely used as materials for the sealing surfaces of container equipment in order to address the issue of crevice corrosion at those surfaces. 2. Applications of titanium materials Due to their excellent corrosion resistance, titanium materials are widely used in various fields such as petroleum, chemicals, salt production, pharmaceuticals, metallurgy, electronics, aviation, aerospace, and marine industries. Titanium exhibits excellent corrosion resistance in most salt solutions; for example, it is more resistant to corrosion in chloride solutions than high-chromium-nickel steel, and no pitting occurs. However, the corrosion rate is relatively high in aluminum trichloride, which is related to the formation of concentrated hydrochloric acid upon the hydrolysis of aluminum trichloride. Titanium also exhibits good stability against hot sodium chlorite and hypochlorites of various concentrations. Therefore, titanium materials are widely used in the vacuum salt production and bleaching powder industries. Titanium exhibits good corrosion resistance to most alkaline solutions. Titanium is relatively stable in sodium hydroxide and potassium hydroxide solutions with concentrations below 50%. If the alkaline solution contains chloride ions or chlorides, its corrosion resistance even exceeds that of nickel and zirconium. However, corrosion increases as temperature and concentration rise. Currently, the chlor-alkali industry is the largest sector for the application of titanium materials in domestic civilian use. Titanium is not resistant to corrosion in dry chlorine and is prone to ignition, but it exhibits high stability in humid chlorine. Its stability exceeds that of zirconium, Hastelloy C, and Monel alloy; it remains stable even in media such as sulfuric acid, hydrochloric acid, and chlorides containing saturated chlorine. Therefore, titanium is the preferred material for key equipment in the production of titanium dioxide via the sulfuric acid process. Due to its excellent corrosion resistance in hydrocarbons, titanium also maintains good resistance even in the presence of acidic and chloride impurities. Therefore, titanium is also widely used in the organic chemical industry, such as in PTA (purified terephthalic acid) and PVA (vinyl alcohol). Titanium exhibits excellent corrosion resistance in seawater; therefore, it is widely used in marine applications such as offshore oil drilling platforms and seawater desalination.

May I ask about the source of the data? Some of the figures don’t match what I saw