Question

Stainless steel is a very useful material for our life. In stainless steel, iron is mixed with:
A. Ni and Cr
B. Cu and Cr
C. Ni and Cu
D. Cu and Au

Answer 1

Stainless steel is the alloy that contains metals in different compositions. Such a composition of stainless steel is very useful as it prevents the iron from rusting. Also, it provides heat-resistant properties.

Complete step by step answer:
- Alloy is a metallic substance, which is composed of two or more elements, as either a compound or a solution. The components of alloys are ordinarily themselves metals.
- The main constituent of stainless steel is iron and also called as the iron-based alloy. Also, besides iron, it consists of 10% to 30% chromium (mainly estimated as 17%), and 4.5% nickel. This formula has 6.5% manganese to partially substitute for the lower nickel content. Such a composition of stainless steel is very useful as it prevents the iron from rusting. Also, it provides heat-resistant properties to the material. This is mainly because of the presence of chromium in the alloy.
- The layer of chromium undergoes passivation (The phenomenon of the materials of becoming less affected by the environment) and protects the other materials in the alloy from corrosion. Also, it can repair the damage itself in the presence of oxygen. We can also further increase the corrosion-resistant power of stainless steel in some ways. For example, if we increase the chromium content to the level above 11%, or if we add nickel 8% or more than that to the composition, we can increase the level of resistivity.

The correct option is (A).

Note: There are different types of the composition of stainless steel. Always remember, stainless steel has very lower carbon content. It varies differently for different compositions of stainless steel, ranging from 0.03% to slightly greater than 1%. Also, other elements in stainless steel are nitrogen, aluminium, silicon, sulfur, copper, selenium, titanium, molybdenum, etc. Different types of stainless steel are named differently by a three-digit number. For example, 304, or 316-stainless steel, etc.