What type of bonding occurs when steel is carburized?

When steel is carburized, interstitial bonding occurs as carbon atoms are diffused into the iron matrix of the steel. This process enhances the properties of the steel, particularly its hardness and strength. In interstitial bonding, smaller atoms like carbon occupy the interstitial spaces between the larger iron atoms in the crystalline structure.

This type of bonding is significant because it allows for the modification of the steel's microstructure without distorting it significantly, unlike covalent or hydrogen bonding, which involve different mechanisms. Mechanical bonding, on the other hand, typically refers to the adhesion between materials without chemical interaction, making it different from what happens during carburization. Therefore, interstitial bonding is crucial to the carburization process and the resultant improvement in the material properties of the steel.