Features of No.4 stainless steel coil
Because sulfides are present in all steels. Moreover, they can act as corrosion catalysts. Therefore, when there is relatively large damage on the steel surface, it is difficult to keep its surface clean.
In general, the corrosion resistance of No. 4 is often lower than that of the finished BA or 2B finishes.
Moreover, the surface of No. 4 is also related to corrosion. When the surface is vertical first, its corrosion resistance will be better.
In some places where the requirements for corrosion resistance are not very high, its corrosion resistance will not affect the normal use of the product.
However, under conditions such as the ocean and the atmosphere, its corrosive will be lower.
But some manufacturers will take some measures to improve its corrosion resistance. For example, pickling the surface of No. 4 stainless steel in a mixture of hydrofluoric acid and nitric acid.
Or passivize its surface in a nitric acid solution.
And then, this can improve the corrosion resistance of No.4 stainless steel coating.
Besides, the privation treatment can dissolve the sulfide on the surface of No.4. Moreover, this will not change its appearance.
Similarly, pickling can also remove sulfide on its surface. However, its appearance will darken.
Unfortunately, though these two methods, even if people control the temperature and contact time of the treatment process, a completely smooth and uniform surface cannot be obtained. Moreover, people cannot often passivize No. 4 stainless steel.
Therefore, electro-polishing the surface of No. 4 stainless steel can improve its corrosion resistance. At the same time, it can brighten its surface.
There are two types of No.4 stainless steel.
Next, let’s take a look at it in detail