Q1: Which of the following is not used as an alloying element in steel used for making permanent magnetic material ?

ANS:C - Vanadium

Vanadium is a transition metal that is commonly used as an alloying element in steel and other materials. It has several properties that make it valuable in various applications:

1. Strength and Toughness: Vanadium can significantly increase the strength and toughness of steel when added in small quantities. It forms very hard and stable carbides, which helps to refine the grain structure of steel, making it stronger and more resistant to wear and fatigue.
2. Hardenability: Vanadium enhances the hardenability of steel, allowing it to be hardened more deeply during heat treatment processes such as quenching and tempering. This property is crucial for producing components that require high strength and hardness, such as gears, springs, and cutting tools.
3. Corrosion Resistance: Vanadium-containing steels exhibit improved corrosion resistance compared to plain carbon steels. This makes them suitable for applications where resistance to rust and corrosion is important, such as in marine environments or chemical processing plants.
4. Magnetic Properties: Vanadium can also contribute to the magnetic properties of certain materials. In steel alloys used for making permanent magnets, vanadium can enhance the magnetic performance and stability of the magnet.
5. Alloying with other Metals: Vanadium is often alloyed with other metals such as chromium, molybdenum, and tungsten to produce high-strength, high-performance alloys for applications in aerospace, automotive, and tooling industries.