Q1: Pick out the wrong statement about coating/electroplating of metals.

ANS:D - Calorising is the process of coating steel with chromium.

It seems there was a mistake in the statement provided. Calorising is not a process of coating steel with chromium. Calorising, also known as aluminizing or diffusion coating, is a thermochemical diffusion process used to improve the surface properties of steel, typically to enhance its resistance to high-temperature oxidation and corrosion. In calorising, aluminum is diffused into the surface of the steel substrate, forming a protective aluminum-rich layer. This layer provides excellent resistance to oxidation and corrosion at elevated temperatures, making it suitable for applications in high-temperature environments such as industrial furnaces, heat exchangers, and automotive exhaust systems. The process typically involves heating the steel component in a controlled atmosphere containing aluminum powder or aluminum-rich gases. At elevated temperatures, aluminum atoms diffuse into the surface of the steel, forming intermetallic compounds such as iron aluminides. These compounds create a diffusion layer with improved surface properties, including high-temperature oxidation resistance, adhesion, and thermal stability. It's important to note that calorising is not a process for coating steel with chromium. Chromium coating processes, such as chromium plating or chrome plating, involve electroplating chromium onto the surface of the steel substrate to provide enhanced corrosion resistance, improved hardness, and decorative appearance. These processes are distinct from calorising and serve different purposes in surface engineering.