This set of Materials Science Multiple Choice Questions & Answers (MCQs) focuses on “Steels”.
1. Which of the following is an alloy of iron and carbon?
Explanation: Steel is an alloy of iron and carbon while solder, bronze and brass are alloys of different metal other than iron.
2. Which of following crystalline form can iron not take?
d) It can take all crystalline forms
Explanation: The correct answer is HCP or hexagonal close packing. Iron can take the crystalline structure of BCC and FCC according to the temperature.
3. Which of the following can be the carbon weight percentage in steel?
Explanation: In a typical steel, the carbon may contribute the maximum of 2.14% of the weight of the alloy. Therefore only 2% lies within the range and hence is the correct answer.
4. Which of the following cannot be used as an alloying element in steel?
Explanation: Lead cannot be used as an alloying element in steel. While chromium, nickel and tungsten are used as an alloying element in steel according to which the carbon percentage in the steel is found out.
5. Traces of which of the following element is considered undesirable in steel?
Explanation: Traces of copper, oxygen and nitrogen are undesirable in a steel alloy whereas chromium, boron and titanium are common alloying elements of steel alloy.
6. Which of the following element is added to steel to form stainless steel?
Explanation: Chromium is added to steel to inhibit corrosion and in a quantity of at least 11%. An oxide protection is formed on the surface of the steel, the alloy thus formed is called stainless steel.
7. At room temperature which is the most stable form of iron?
Explanation: At room temperature, the most stable form of iron is BCC structure which is also called as α-iron.
8. When steel with exactly 0.8% carbon by weight is cooled, the FCC structure of the mixture tries to revert back to its BCC structure.
Explanation: The above statement is true. When steel with exactly 0.8% carbon by weight is cooled, the FCC structure of the mixture tries to revert back to its BCC structure.
9. Adding a nickel to the steel alloy increases its tensile strength.
Explanation: The above statement is true. Nickel is added to the steel alloy to increase its tensile strength and make its austenite structure more stable.
10. Which of the following can be the density of steel?
a) 8.1 g/cm3
b) 7.8 g/cm3
c) 7.7 g/cm3
d) 8.2 g/cm3
Explanation: The density of steel varies between 7.75 g/cm3 and 8.05 g/cm3. As only 7.8 g/cm3 lies in that range and the others are beyond the range, 7.8 g/cm3 is the correct answer.
Sanfoundry Global Education & Learning Series – Materials Science.
To practice all areas of Materials Science, here is complete set of 1000+ Multiple Choice Questions and Answers.