Present in all steels, it is the most important hardening element. Also increases the strength of the steel. Despite the name, all steel can rust if not maintained properly. Contributes to strength. Like manganese, it makes the steel more sound while it's being manufactured.
Increases wear resistance.
When combined properly with chromium or molybdenum, tungsten will make the steel to be a high-speed steel. Contributes to wear resistance and hardenability. A carbide former that helps produce fine-grained steel. These steels are the steels most often forged. In addition, carbon steels can be differentially tempered, to give a hard edge-holding edge and a tough springy back.