Effect of alloying elements in steel
 

Alloying elements are added to steel to enhance its properties beyond pure iron. Here's a concise overview of how various alloying elements affect steel:
1. Carbon (C): Increases hardness and strength, but reduces ductility and toughness. It's the primary element in steel, and its percentage greatly influences steel's characteristics.

2. Manganese (Mn): Enhances strength and hardness. Improves workability by counteracting brittleness from sulfur. It can help reduce the critical cooling rate for hardening. 

3. Silicon (Si): Increases strength and hardness, especially in spring steels. Improves oxidation resistance. Affects the electrical properties, used in transformer steel.

4. Chromium (Cr): Significantly improves corrosion and oxidation resistance, essential in stainless steel. Increases hardenability and wear resistance.

5. Nickel (Ni): Enhances toughness, particularly at low temperatures. Improves corrosion resistance and surface finish. Increases hardenability.

6. Molybdenum (Mo): Refines grain size, increasing toughness and strength. Enhances creep resistance at high temperatures. Improves corrosion resistance, particularly pitting in chloride environments.

7. Vanadium (V): Forms hard, wear-resistant carbides.Increases strength at high temperatures without significantly reducing toughness.

8. Tungsten (W): Used mainly in high-speed steels for its ability to retain hardness at high temperatures. Increases the red hardness (hot hardness) of steel.

9. Titanium (Ti): Stabilizes carbides, preventing sensitization in stainless steel. It can refine the grain structure, improving strength.

10. Aluminum (Al): Deoxidizes steel to remove oxygen. It can be used for nitriding to produce a hard surface layer.

11. Copper (Cu): Improves corrosion resistance, especially in atmospheric conditions. Can aid in precipitation hardening.

12. Boron (B): When added in trace amounts, significantly increases hardenability without affecting other properties much.