Question

how do stainless steel become stainless.

Answer 1

Stainless steel become stainless.

It is defined as that steel which when correctly heat treated and finished, resists oxidation and corrosive attack from most corrosive. It is an alloy og iron with a minimun of 10.5% chromium. chromum produce a thin layer of oxide on the surface of the steel known as passive layer. Increasing the amount of chromium gives an increased resistance to corrosion.

stainless steel remains stainless or not rust because of the interaction between its alloying elements and the environment. It contains iron chromium, manganease, silicon, carbon and in many cases, significant amount of nickel and molybdenum. Iron mixed with carbon to produce steel is the main component of stainless steel.

Four type of stainless steel

• Austenitic
• Ferrite
• Duplex
• Martensitic

The different types of stainless steels are follows

1. Martensitic stainless steel : The chromium steels containing 12 to 14 % chromium and 0.12 to 0.35% carbon is called martensitic stainless steel. These steels are magnetic and may be hardened by suitable heat treatment and the hardness obtainable depends upon carbon percentages.
2. Ferritic stainless steel : The steel containing greater amount of chromium from 16 to 18% and 0.12% carbon are called ferritic stainless steel. These steels have better corrosion resistant property than martensitic stainless steels
3. Austenitic stainless steel : The steel containing high cntent of both chromium and nickel are called austenitic steels. The most widely used steel contains 18% chromium and 8% nickel. such a steel is commonly known as 18/8 steel. These are non magnetic and possesses greatest resistance to corrosion and goog mechanical properties at elevated temperature.