Alloy components

Alloy components

Below we present the alloy components, ie CHROME, NICKEL, etc., typical for the composition of stainless steels.

Steels achieve the “stainless steel ceiling” if they contain 12% (and more) chromium in the respective chemical composition. It is he who, reacting with oxygen from the environment, creates a thin protective passive layer on the steel surface. However, the full chemical (anti-corrosive, acid-resistant), mechanical and physical properties of stainless and acid-resistant steels result from the precise selection of appropriate components in the production cycle.

Chromium (chromium, Cr)

This element is the most important alloying component of the steels in question. Its percentage of content varies from 12% to almost 30% depending on the species. It stabilizes the ferritic structure and creates a passive protective layer. It causes grain grinding. Increases hardenability of steel. Increases its endurance. Used in tool, construction and special steels (stainless or heat-resistant).

Nickel (niccolum, Ni)

Nickel plays a large role in acid-resistant steels as a stabilizer of the austenitic structure (good weldability and the possibility of plastic processing). At the same time, it increases the corrosion resistance of steel. It lowers the austenitic transformation temperature and the hardening speed. In practice, this means facilitating the hardening process and increasing the hardening depth. Nickel dissolved in the ferrite strengthens it, significantly increasing the impact strength. The addition of nickel in the amount of 0.5% – 4.0% is added to the steel for quenching and in the amount of 8.0% – 10.0% to the acid-resistant steel.

Molybdenum (molybdaenum, Mo)

This element improves the corrosion resistance of steel. Typical austenitic steels, called acid-resistant steels, contain about 2.5% molybdenum. However, its content can be as high as 7%. Increases the hardenability of steel. Increases strength and reduces brittleness, and increases creep resistance (slow, continuous plastic elongation of metal under constant load).

Silicon (silicium, Si)

Silicon is added to steels operating at elevated temperatures and in contact with concentrated sulfuric and nitric acids. Consequently, it improves the resistance of steel to oxidation and stabilizes ferrite.

Titanium (titanium, Ti)

Titanium is used in situations where it is not possible to keep the carbon content of the steel as low as possible. This element binds carbon (titanium and niobium carbides). It acts as a typical stabilizer for acid-resistant steels.

Carbon (carboneum, C)

Carbon itself is one of the elements that stabilize the austenitic structure. Moreover, it increases the strength properties of steel. In austenitic steels, the nickel content increases with the decrease in carbon content. This is due to the maintenance of a stable austenitic structure.