2. Carbon steel, also called carbon steel, refers to an iron-carbon alloy with a carbon content of Wc less than 2. 1 1%. In addition to carbon, carbon steel generally contains a small amount of silicon, manganese, sulfur and phosphorus.
3. In materials science and metallurgy, toughness refers to the ability to resist fracture under stress, which is defined as the ratio of energy and volume that a material can absorb before fracture.