Roughness and electropolishing: its advantage over other surface finishes

Making stainless steel even more stainless: that is what electropolishing does, and it is why we use it on all our pieces, valves and manifolds.

In a previous article, we mentioned how electropolishing increases the performance of stainless steel. Immersing pieces in a galvanizing bath, in fact, exalts the natural phenomenon of passivation, on which the ability of stainless steel to resist corrosion depends.

Here, instead, we want to highlight an additional advantage of electropolishing that is particularly important to the food and medical sectors: smooth outer and inner surfaces. By acting on the roughness, and consequentially increasing smoothness, electropolishing answers the highest hygiene requirements of specific applications.

The focus is on the manifold pipes we produce in particular, because they are the perfect shape for internal electropolishing.

How electropolishing acts on roughness

If you observe the surface of a stainless steel manifold using a surface roughness tester you can see, on a microscopic level, that it is not perfectly smooth, but that it has small peaks and valleys. The electrochemical action acts on the peaks, eroding them and softening the surface.

We discovered that the roughness levels obtained from electropolishing can be compared with those of rectification, a term applied when the roughness values are below 0.8 micron. With electropolishing, a value of even 0.4 micron can be reached.

In the image showing a surface treated with electropolishing you can see a roughness Ra 0.438 µm.

The smoother the grain, the higher the guarantee of piece cleanliness and the smaller the risk of deposits and scale. This result, obtained electrochemically, is preferable to mechanical smoothing, which always causes micro-abrasions that can lead to the possible release of metal particles.

Contact us if you want more information on electropolishing and advice on the best solution for your needs!