Mechanical Engineering - Engineering Materials - Discussion

What is porous? Can anyone define?

Porous - Tiny holes.

I think, the correct option is manganese.

Silicon reacts with the oxygen present in the steel. Thus the porosity decreases.

The correct answer is: Manganese.

Manganese (Mn) is added to low-carbon steels to:

1. Prevent porosity: Manganese combines with sulfur to form manganese sulfide, which reduces the formation of pores and improves the steel's density.
2. Improve hot-working properties: Manganese helps to reduce the steel's susceptibility to hot-shortness, making it easier to forge and shape.
3. Enhance strength and hardness: Manganese is a solid-solution strengthener, increasing the steel's strength and hardness.

The other options are not accurate:

- Sulphur (S): Sulphur can contribute to porosity and hot-shortness in steel, so it's not added to prevent porosity.
- Phosphorus (P): Phosphorus is added to steel to improve its machinability, but it can also increase the risk of porosity and embrittlement.
- Silicon (Si): Silicon is added to steel to improve its electrical properties, corrosion resistance, and high-temperature properties, but it's not typically added to prevent porosity in low-carbon steels.

The specific addition of manganese or other elements depends on the steel grade, application, and desired properties.