To compensate, at least 10.5% or more chromium is added. This steel is generically known as stainless steel. The added chromium creates a superficial and extremely thin oxide layer, called a passivation layer which protects the blade from corrosion.
The higher the carbon content in steel, the harder it gets through heat treatment. Hardness guarantees a long-wearing cutting quality. It is therefore quite tempting to use a high carbon content grade.
There are however two limitations on increasing the carbon content:
1. The harder the blade, the more fragile it becomes. This is true for both types of steel, whether it is carbon steel or stainless steel.
2. A high carbon content in stainless steel reduces its resistance to corrosion. Carbon tends to combine with chromium to form chromium carbides. As a carbide, chromium loses its protective properties against oxidation.