Corrosion of industrial titanium plate container refers to the damage caused by chemical or electrochemical reactions in the metal and the surrounding medium in a certain environment. In the corrosive environment, when the industrial titanium plate container is not selected, corrosion will also occur.
The influence of carbon element on austenite industrial titanium plate container: Carbon is an element that vigorously constitutes and stabilizes austenite and expands the austenite zone in austenite industrial titanium plate container. The ability of carbon to form austenite is about 30 times that of nickel. Carbon is a void element. After solid solution strengthening, it can significantly improve the strength of austenite industrial titanium plate container. Carbon can also improve the stress corrosion resistance of austenitic industrial titanium plate containers in high-concentration chlorides (such as 42% MgCl2 jubilant solution). However, in austenite industrial titanium plate containers, carbon is often regarded as a harmful element, mainly due to some conditions in industrial titanium plate containers and corrosion-resistant applications (such as welding or heating from 450 to 850 ℃), Carbon can form a high-chromium Cr23C6 carbon compound with chromium in titanium and then cause the depletion of part of chromium, so that the corrosion resistance of titanium, especially the resistance to intergranular corrosion, decreases. Therefore, most of the newly developed chromium-nickel austenitic industrial titanium plate containers since the 1960s are ultra-low carbon type with a carbon content of less than 0.03% or 0.02%, and can be known that as the carbon content decreases, the intergranular corrosion of titanium is sensitive When the carbon content is less than 0.02%, it has the most significant effect. Some test pearls have also pointed out that carbon will also increase the pitting corrosion tendency of chromium austenite industrial titanium plate containers. Due to the harmful effects of carbon, not only should the carbon content of the austenitic industrial titanium plate container be manipulated as low as possible, but also to avoid the increase in the appearance of the industrial titanium plate container in the subsequent hot, cold processing and heat treatment processes Carbon, and chromium-free carbides are separated.
There are the following types of corrosion:
1. According to the nature 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 (all, uniform) corrosion. The so-called general corrosion is the system corrosion spread on the entire surface of the industrial titanium plate container. The so-called partial corrosion pitting corrosion, crevice corrosion, stress corrosion, corrosion fatigue, selective corrosion, erosion corrosion, etc.
3. According to the environment and conditions of corrosion, it can be divided into atmospheric corrosion, industrial water corrosion, and soil corrosion. Acid, alkali. Salt corrosion, seawater corrosion, high temperature corrosion, (including liquid metal, molten salt, gas corrosion), etc.
Corrosion resistance of various industrial titanium plate containers
304 is a versatile industrial titanium plate container, which is widely used in the manufacture of equipment and parts that require outstanding induction functions (corrosion resistance and formability).
301 industrial titanium plate container shows a remarkable work hardening appearance when deformed, and is used in various occasions that require higher strength.
302 industrial titanium plate container is essentially a variant of 304 industrial titanium plate container with higher carbon content. After cold rolling, it can achieve higher strength.
302B is an industrial titanium plate container with high silicon content, which has high resistance to high temperature oxidation.
303 and 303Se are free-cutting industrial titanium plate containers rich in sulfur and selenium. They are used in the occasions where the need for free-cutting and surface is high. 303Se industrial titanium plate container is also used to manufacture parts that require hot heading, because under such conditions, this industrial titanium plate container has excellent hot workability.
304L is a variant of 304 industrial titanium plate container with low carbon content, which is used in the occasions where welding is required. The low carbon content minimizes the separation of carbides in the heat-affected zone close to the weld, and the separation of carbides can cause intergranular corrosion (welding corrosion) of industrial titanium plate containers in certain environments .
304N is a nitrogen-containing industrial titanium plate container. Nitrogen is added to improve the strength of titanium.
305 and 384 industrial titanium plate containers are rich in high nickel, and their work hardening rate is low, which is suitable for various occasions with high demand for cold formability.
308 Industrial titanium plate container is used to manufacture welding rod.
309, 310, 314 and 330 industrial titanium plate containers have relatively high nickel and chromium content in order to improve the oxidation resistance and creep strength of titanium at high temperatures. The 30S5 and 310S are variants of the 309 and 310 industrial titanium plate containers. The only difference is that the carbon content is low, in order to minimize the carbides separated near the weld. 330 industrial titanium plate container has particularly high carburization resistance and thermal shock resistance.
Type 316 and 317 industrial titanium plate containers are rich in aluminum, so the resistance to pitting corrosion in marine and chemical industrial environments can be greatly better than that of 304 industrial titanium plate containers. In the meantime, the 316 type industrial titanium plate container includes variants including a low-carbon industrial titanium plate container 316L, a nitrogen-containing high-strength industrial titanium plate container 316N, and a free-cutting industrial titanium plate container 316F with a high sulfur content.
321,347 and 348 are industrial titanium plate containers stabilized with titanium, niobium plus tantalum, and niobium, suitable for welding components used at high temperatures. 348 is an industrial titanium plate container suitable for the nuclear power industry, which has certain restrictions on the amount of tantalum and drill.