Q1: Work hardenable alloy steel used to make the bucket wheel excavators, blades of bulldozers and other earth moving equipments contain iron, carbon and

ANS:A - manganese

Manganese (Mn) is a chemical element commonly used as an alloying element in steel production. Here's an explanation of its role and importance:

1. Hardenability: Manganese is one of the main elements used to enhance the hardenability of steel. Hardenability refers to the ability of steel to be hardened by heat treatment processes such as quenching and tempering. Manganese promotes the formation of fine-grained structures during heat treatment, which improves the strength and toughness of the steel.
2. Deoxidation: Manganese is a strong deoxidizer in steelmaking. During the steelmaking process, manganese reacts with oxygen and other impurities present in the molten metal, forming manganese oxides that float to the surface and are easily removed as slag. This helps to ensure the production of clean, high-quality steel with fewer defects.
3. Desulfurization: Manganese also has desulfurizing properties, meaning it can help remove sulfur from the steel. High sulfur content in steel can lead to brittleness and poor mechanical properties. Manganese reacts with sulfur to form manganese sulfides, which are then removed from the steel as slag, reducing the sulfur content and improving the steel's quality.
4. Work Hardening: Manganese is also known for its ability to enhance the work hardening properties of steel. Work hardening, also known as strain hardening or cold working, is the process by which the strength and hardness of a material increase as it is subjected to plastic deformation. Manganese-containing steels exhibit increased work hardening rates, making them suitable for applications where resistance to wear and deformation is required.

Overall, manganese plays a crucial role in steelmaking by improving hardenability, promoting clean steel production through deoxidation and desulfurization, and enhancing the work hardening properties of the steel. It is widely used in various steel grades, including construction steels, railway tracks, wear-resistant steels, and high-strength low-alloy (HSLA) steels.