Question

Stainless steel is an alloy of:
A) $Cu$
B) $Ni$ and $Cr$
C) $Mn$
D) $Zn$

Answer 1

Hint: Stainless steel is an alloy consisting of carbon, iron, chromium, and nickel. Stainless steel contains around 0.015 % to 0.10 % of carbon, 16 % to 21 % of chromium, 6 to 26% of nickel.

Complete step-by-step answer:
Stainless steel is made up of carbon, iron, chromium, and nickel.
Stainless steel was discovered by Harry Brearley of Sheffield in the year 1913. The first stainless steel discovered had 12.8 % of chromium content in it. Stainless steel contains about a minimum of 10.5% chromium. This chromium makes a thin oxide layer on the steel surface which is known as a passive layer. This passive layer prevents the surface from corrosion. The presence of nickel also makes stainless steel more corrosion resistant as well as more ductile.

Hence, option B is correct.

Additional Information:
1. The five types of stainless steel we know are Austenitic, Duplex, Ferritic, Precipitation hardening and Martensitic. Stainless steel is exceptionally durable, they are temperature resistant, they are very durable, it has a low maintenance, they are environmentally friendly that is, it can be recycled, and they are also corrosion resistant.
2. Stainless steel has many uses in our life such as in the manufacturing of various utensils such as cookware, saucepans, it is used in cutlery. Some knives are also made using stainless steel which have less ductility. Stainless steel which is molded into utensils are quite expensive making it inconvenient for the buyers. Maintenance cost of the steel is also high.

Note: Martensitic stainless steel consists of Type 410, 410s, 414, 416, 420, 431 and 440. Ferritic stainless steel consists of Type 430, 405, 409, 434, 436, 442 and 446. Duplex stainless steel consists of Type 2205, 2304 and 2507. Precipitation Hardening stainless steel consists of Type 17-4 and Type 15-5. In Austenitic stainless steel, none of the grades are magnetic.