General knowledge of titanium plate container corrosion

Corrosion of industrial titanium plate containers refers to the damage caused by chemical or electrochemical reactions of the metal and the surrounding medium under certain circumstances.

The influence of carbon on the austenite industrial titanium plate container: carbon in the austenite industrial titanium plate container is the element that strongly forms and stabilizes the austenite and extends the austenite zone. Carbon is about 30 times as effective as nickel in forming austenite. Carbon is a void element and the strength of titanium plate vessels made of austenite can be significantly improved by solid solution strengthening. Carbon also improves the stress corrosion resistance of austenitic titanium plate containers in high concentration chlorides (e.g., 42%MgCl2 exultant solution). But in austenite industrial titanium plate container and carbon is often seen as the harmful elements, the first is due to industrial titanium plate in the container and corrosion resistant USES some of the conditions (such as welding or heating by 450 ~ 850 ℃), carbon and chromium in titanium Cr23C6 type carbon compounds and the part of the high chromium chromium depletion, make the corrosion resistance of titanium especially resistant to intergranular corrosion. Therefore, since the 60 s of the development of new industrial titanium plate cr-ni austenitic container is mostly carbon content less than 0.03% or 0.02% of the ultra-low carbon type, can know with carbon content decreased, and the titanium intergranular corrosion sensitivity decreased, when the carbon content is less than 0.02% is the most significant effect, carbon will also increase the chromium austenitic industrial titanium plate container corrosion tendency. Due to the harmful effects of carbon, not only in the austenitic industrial titanium plate container exercise should be required to control as low as possible carbon content, and in the subsequent hot, cold processing and heat treatment process, also in order to avoid the appearance of industrial titanium plate container carbon, free from chromium carbide separation.

Corrosion can be classified as follows:

1. According to the properties of the effect, it can be divided into chemical corrosion and electrochemical corrosion.

2. According to the shape of corrosion, it can be divided into normal (total, even) corrosion. The so-called general corrosion, corrosion spread in the entire industrial titanium plate container surface, the so-called partial corrosion pitting corrosion, crevice corrosion, stress corrosion, corrosion fatigue, selective corrosion, erosion corrosion and so on.

3, according to the corrosion attack environment and conditions can be divided into atmospheric corrosion, industrial water corrosion, soil corrosion. Acid and alkali. Salt corrosion, seawater corrosion, high temperature corrosion, (including liquid metal, molten salt, gas corrosion).

Corrosion resistance of various industrial titanium plate containers

304 is a universal industrial titanium plate container, which is widely used in the manufacture of equipment and parts with inductive functions (corrosion resistance and formability).

301 industrial titanium plate containers show obvious appearance of work hardening during deformation and are used in various occasions requiring higher strength.

302 industrial titanium plate container is essentially a higher carbon content of 304 industrial titanium plate container varieties, after cold rolling can make it obtain higher strength.

302B is a kind of industrial titanium plate container with high content of silicon, which has high resistance to high temperature oxidation.

303 and 303Se are free cutting industrial titanium plate containers rich in sulfur and selenium, which are used for prime cutting needs. The 303Se industrial titanium plate container is also used to manufacture hot upsetting machines due to its outstanding thermal processability under such conditions.

304L is a low carbon 304 industrial titanium plate container variety, used for welding occasions. The lower carbon content minimizes the separation of carbides in the heat-affected zone near the weld seams, which can cause intergranular corrosion (weld corrosion) in industrial titanium plate containers in some environments.

304N is an industrial titanium plate container containing nitrogen. Nitrogen is added to improve the strength of titanium.

305 and 384 industrial titanium plate containers are rich in nickel and have low work hardening rate, which is suitable for various occasions with high demand for cold formability.

308 industrial titanium plate containers are used for manufacturing welding rods.

Industrial titanium plate vessels of 309, 310, 314 and 330 have relatively high nickel and chromium content, so as to improve the oxidation resistance and creep strength of titanium at high temperature. While 30S5 and 310S are variations of 309 and 310 industrial titanium plate containers, the difference is only a low carbon content, in order to minimize the amount of carbide separated from the adjacent weld seams. The 330 industrial titanium plate container has a particularly high carburizing ability and thermal shock resistance.

Type 316 and 317 industrial titanium plate containers are rich in aluminum, so their resistance to spot corrosion in Marine and chemical industrial environment is much better than that of 304 industrial titanium plate containers. Meanwhile, type 316 industrial titanium plate container consists of varieties including low-carbon industrial titanium plate container 316L, high-strength industrial titanium plate container 316N containing nitrogen, and free-cutting industrial titanium plate container 316F with high sulfur content.

321, 347 and 348 are industrial titanium plate containers separated from titanium, niobium, tantalum and niobium. 348 is an industrial titanium plate container suitable for nuclear power industry, which has certain restrictions on the combination of tantalum and drill.