Is 20# steel resistant to sulfur?
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This post was last edited by Gunao Biao Kun on January 8, 2012, at 10:13. Is 20# steel resistant to sulfur? Just asking about the sulfur resistance of 20-grade steel? Don’t recommend sulfur-resistant materials to me.
20# steel belongs to low-carbon steel; its main component is Fe. This applies whether it is elemental sulfur or reactive sulfides such as hydrogen sulfide and thiols. They all react with the metal Fe; if water is present, hydrosulfuric acid is formed, leading to more severe corrosion.
Steel 20 is not resistant to sulfur, but it can be used in sulfur-containing environments. When iron reacts with sulfur to form ferrous sulfide, this forms a dense protective layer on the inner walls of the container; therefore, it is sufficient to leave an adequate amount of corrosion resistance (usually 1 mm is enough)
You can take a look at the research on the welding process for sulfur-resistant pipelines made of 20# steel, from the Daqing Oil Field
However, in pipes with high flow rates or in areas where vortices are likely to form, this layer of ferrous sulfide protective film is not effective.
It depends on the operating conditions and medium conditions! ?
Reply to 5# Wang Yongsheng: Sulfur corrosion is a type of chemical corrosion, and chemical corrosion occurs uniformly across the entire surface of a pipe or container. Therefore, when the corrosive conditions are mild, it is still possible to use 20-grade steel. The concern is that punctate stress corrosion might occur, which could lead to unpredictable accidents.
The answer given by the moderator on floor 7 is reliable~~ It is necessary to calculate the flow rate and erosion capacity~~ It is recommended to choose a flow rate at the lower end of the permitted range, and increase the pipe diameter accordingly; this will effectively extend the service life of 20# pipes.