Is the hardness or softness of the steel with higher carbon content?
With the increase of carbon content, the strength and hardness of steel increase, while the plasticity and toughness decrease. When the carbon content is more than 1%, the strength of steel decreases.
Carbon is the major element in determining the properties of steel, because changes in carbon content lead directly to changes in crystal structure.
The increase of carbon content also reduces the weldability and corrosion resistance of steel, and increases the cold brittleness and aging tendency of steel.
