Question

Stainless steel contains:
A. Cu and Zn
B. Cu and Sn
C. Pb and Sn
D. Fe, C, Cr and Ni

Answer 1

Hint:The stainless steel is the class of iron alloy which is resistive to corrosion and higher thermal effect due to the presence of different metals. The main metal used is chromium which is present in more than 11%.

Complete step by step answer:
A stainless steel is the alloy of iron which generally contains 11% chromium which helps in preventing the steel from rusting. The chromium present in the stainless steel also provides heat resistant properties.
Many stainless steel contains elements like carbon, nitrogen, sulphur, aluminium, selenium, nickel copper and other elements.
The presence of chromium in the stainless steel makes it resistant to the formation of ferric oxide which forms a passive film which protects the metal from the corrosion and can self heal in the presence of oxygen. The resistance toward corrosion is increased by increasing the percentage of chromium above 11 %, by adding more percentage of nickel, by addition of molybdenum.
After the formation of stainless steel from the iron alloy it is melted in the electric arc and furnace, refined in steel making vessels. It is done to lower the content of carbon.
Thus, stainless steel contains Fe, C, Cr and Ni.
Therefore, the correct option is D.

Note:
There are mainly 100 grades of stainless steel, which are characterized in five groups in the family of stainless steel. They are austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, duplex stainless steel and precipitation-hardening.