what are the characteristics when of iron or steel when stretched? which one could be stretched further? which one stretches more evenly?thankyou
Steel is harder and more brittle than iron since it has impurities which disrupt the regular layers of atoms. This means that the iron will stretch further and more easily. This also means it will stretch more easily.
Technically, this is known as ductility. a material which can be permanently bent and stretched is said to be ductile. Pure iron, when it lacks carbon and impurities like sulfur and phosphorus, is relatively soft, ductile, and weak. It's about as soft as brass. It can be stretched to about 50% of it's original length before it breaks. The amount a sample can be stretched without breaking is known as elongation. The key to steel is the addition of about 2 parts per thousand of carbon, or around 0.2%. This alters the crystal structure and makes steel much harder, stronger, and tougher, though it also becomes somewhat less ductile. Mild steel, with a low carbon content, has an elongation of around 30% Adding more carbon makes the steel yet stronger, but further reduces the elongation. Adding more than 2-3% carbon produces what is known as Cast Iron. Cast iron is brittle. It has virtually no ductility. It's pretty cheap to produce though.
