Mechanical properties:

      Hardness: Annealing, ≤269HB; Quenching and tempering, ≥58HV

      Mechanical properties: Internal stress (250 N/mm2) Tensile strength (560 N/mm2) EL (18 %) HB (250)

Heat treatment process

Heat treatment specification and metallographic structure: Heat treatment specification:

      1) Annealing, slow cooling at 800～920℃;

      2) Quenching, 1010～1070℃ oil cooling;

      3) Tempering, 100 ~ 180 ℃ rapid cooling.

Metallographic structure: The structure is characterized by martensitic type.

      Among the domestic stainless steel grades, 440C has higher hardness. Mainly used to manufacture bearing parts working in corrosive environment and non-lubricated strong oxidizing atmosphere. 440C has good high temperature dimensional temperature, so it can also be used as corrosion-resistant high-temperature bearing steel. In addition, it can also be used to manufacture high-quality knives, such as medical scalpels, scissors, nozzles, bearings, etc. 440F: It is a steel grade that improves the easy-cutting properties of 440C steel. It is used in automatic lathes. Martensitic stainless steel has the same characteristics of hardening through quenching as ordinary alloy steel. Therefore, a wider range can be obtained by selecting grades and heat treatment conditions. different mechanical properties. The 440C has a lower ability to withstand dynamic loads.

      After quenching, 440C has high hardness and good corrosion resistance (magnetic). Cutlery (knife), turbine blades After quenching, the hardness is higher than that of 440A steel (magnetic). Blades, nozzles, valves, plate rulers, tableware (scissors).