Because bone chopping knives have requirements for hardness and toughness, the main material of high-quality kitchen bone chopping knives is martensitic stainless steel.
Martensitic stainless steel is mainly low carbon or high carbon steel with a chromium content in the range of 12%-18%. There are three types of martensitic stainless steel widely used in various countries:
1. Low carbon and medium carbon 13% Cr steel
2. High carbon 18% Cr steel
3. Low carbon 17% Cr steel containing nickel (about 2%)
Extended information:
Martensitic stainless steel has high strength and corrosion resistance , can be used to manufacture mechanical components, such as steam turbine blades (1Cr13), steam equipment shafting (2Cr13), valves and bolts and other components that work in corrosive media (4Cr13). Steel grades with higher carbon content (4Cr13, 9Cr18) are suitable for manufacturing medical equipment, table knives, measuring tools, springs, etc.
Martensitic stainless steel, like tempered steel, can be quenched, tempered and annealed. Its mechanical properties are similar to those of modulated steel: hardness increases, tensile strength and yield strength increase, and elongation, area reduction and impact energy decrease.
The corrosion resistance of martensitic stainless steel mainly depends on the chromium content. The carbon in the steel and chromium form stable chromium carbide, which indirectly affects the corrosion resistance of the steel. Therefore, in 13% Cr steel, the lower the carbon content, the higher the corrosion resistance. The corrosion resistance and strength of 1Cr13, 2Cr13, 3Cr13 and 4Cr13 steels are in the opposite order.