The content of manganese in 20 1 stainless steel is high, and it is easy to precipitate when it comes into contact with acidic substances. 20 1 contains 17 chromium and 5 nickel. For 304 stainless steel, chromium containing 19 and nickel containing 10 directly determine the corrosion resistance and value of 304 stainless steel.
Because the carbon element in 20 1 steel is higher than that in 304 steel, 20 1 stainless steel is more brittle and harder than 304 stainless steel, and 304 steel has good toughness. When scraping the surface of 20 1 steel with a knife, there are usually obvious scratches, but the scratches on 304 steel are not obvious, so 304 stainless steel has better corrosion resistance, acid and alkali resistance and other properties. 304 stainless steel is more expensive than 20 1 stainless steel because of its superior performance in all aspects.
Introduction of stainless steel manufacturing methods;
1, melting raw materials
Put different stainless steel materials into a furnace and heat them to their melting points. This process may take 8 to 12 hours. Once the metal melts, stainless steel manufacturing can proceed to the next step.
Step 2 remove excess carbon
The molten material is put into a vacuum oxygen decarbonization or argon oxygen decarbonization system to remove excess carbon. Depending on the amount of carbon removed, this process can produce standard or low-carbon alloys, such as 304 and 304L stainless steel. This will affect the tensile strength and hardness of the final product.
Step 3 Tune or stir
To help fine-tune the quality of the final product, molten steel can be stirred to help disperse from the mixture, or some stainless steel components can be removed. This helps to ensure that stainless steel has uniform quality and meets the specifications required by end users.
4. Molded metal
When stainless steel begins to cool, it will go through various forming processes, starting from hot rolling, when the steel is still above its crystallization temperature. Hot rolling helps to make steel into rough shapes, and is usually used to make metal billets or ingots. In order to manufacture metal blanks or billets with precise dimensions, stainless steel can be cold rolled.
5, heat treatment or annealing
In order to reduce the internal stress and change the mechanical properties of stainless steel, it can be annealed. If annealed, it may be necessary to derust the steel to avoid damaging the oxide layer.
6, cutting and forming
After the annealing process, stainless steel goes through various cutting and forming processes to produce an ideal final product suitable for the application. The specific operation of cutting stainless steel will vary according to the size and shape of the blank, large flowers and the required final product. For example, if a thick metal plate is manufactured, a large metal shearing machine can be used to mechanically cut the steel.
7, the application of surface treatment
Stainless steel manufacturers can carry out different surface treatments on stainless steel billets, billets or wires before transporting them to other manufacturers. The specific surface treatment will vary according to the intended use of steel, but one of the most common surface treatments is simply grinding the surface to remove impurities and make it smoother.
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