Stainless steels are highly resistant to corrosion in atmospheric conditions and some other environments (gas environment, river and sea water, some acids, alkalis and salt solutions) at indoor and elevated temperatures. Chromium is the main alloying element providing the metal corrosion resistance. The plastic properties of the alloy are achieved by adding 8-11% nickel. Nickel makes stainless steel tensile and thus facilitates the forming operation. Chromium addition to the alloy results in the formation of chromium carbide at the grain boundaries, which increases the possibility of grain-boundary corrosion initiation. In order to reduce the possibility of carbide formation, titanium is added to the stainless steel composition and, getting combined with carbon, forms titanium carbides. Chromium and nickel steels have the largest specific density in stainless steel smelting and they are more widely used in industry. They are used in manufacture of bar and flat products, forged pieces, hot-rolled and cold-rolled pipes, and in casting in various fields of engineering and industry (chemical, nuclear, aerospace and etc.). Steels of this type can be divided into the following subgroups:
- Chromium-nickel austenitic stainless steels with low carbon content.
- Chromium-nickel austenitic acid-resisting stainless steels.
- Chromium-nickel nonscaling steels with of high content of chromium and nickel.
- Chromium-nickel martensitic-austenitic steels.
- Chromium-nickel ferritic-austenitic steels.
Performance of stainless steel electrolyte-plasma treatment and polishing:
Recommended processing time for stainless steel polishing — 180 sec.
Grinding and deburring speed — 30 sec.
Average time to reduce the roughness value by 1 class — 75 sec.
The number of polishing cycles before changing the electrolyte - 960.