A, 440C stainless steel 
 440C has the highest hardness of all stainless steel, heat-resistant steel. For nozzles, bearings .440 F: to improve the performance of 440C steel easy to cut steel. For automatic lathes. Martensitic stainless steel and alloy steel has the same features, hardened by quenching to a wide range of different mechanical properties by selecting the grade and heat treatment conditions. 
 C-1.2% of this steel rust resistant 440C stainless steel carbon content, is more commonly used stainless steel imports produced a knife, its chromium content up to 16-18%, is also one of the earliest stainless steel for tool making. popular. As stainless bearing steel heat treatment, deep cryogenic treatment is generally recommended before tempering operations. This cryogenic processing improves the hardness of the steel, increasing the wear resistance and dimensional stability. Therefore, the 440C of the deep cryogenic treatment, also often used for tool heat treatment. 
 Two, 440C stainless steel Features: 
 The high hardness and moderate wear resistance, in the polished, its drawback is that the viscosity is relatively large, but warming quickly. Suggested the use of chromium corundum or microcrystalline corundum grinding wheel for grinding. 440C annealing temperature is very low, as a tool and bearing the heat treatment time, usually hardness can reach HRC57-59, if the cryogenic treatment, the hardness can reach HRC59-61. Corrosion resistance and toughness are very strong, is now more widely used in hand-made knives and high-quality plant system tool. 
 Three, 440C stainless steel Usage: 
 440C for a win and one hundred special steel quenching hardness, good corrosion resistance (magnetic) cutlery (knife), after quenching of the turbine blades, higher than the hardness of the 440A steel (magnetic), blades, nozzles, valves, board feet cutlery (scissors). 
 Mechanical properties: 
 Internal stress (250 N/mm2) tensile strength (560 N/mm2) EL (18%) HB (250) 
 Fourth, the 440C stainless steel chemical composition (%): 
 C: 1.10 
 Mn: 1.00 
 P: 0.03 
 S: 0.010 
 Cr: 17.50 
 Mo: 0.60 
 Ni: 0.60 
 Cu: 0.50 
 Si: 1.00 
 Five, 440C stainless steel characteristics of the application: 
 In the domestic stainless steel grades, the 440C has a higher hardness. Mainly used in the manufacture of the bearing parts of the corrosive environment and lubrication strong oxidizing atmosphere. 440C has good high temperature dimensional temperature, so it can be used as corrosion-resistant high-temperature bearing steel. In addition, it can be used to create high-quality tool, such as medical scalpels, scissors, nozzles, bearings, etc.. 440F: to improve the performance of 440C steel easy to cut steel for automatic lathes, martensitic stainless steel and alloy steel has the same characteristics of hardening by quenching, so you can select the grade and heat treatment conditions to get a wider range of different mechanical properties. 440C ability to withstand the dynamic load is low. 
 Six, 440C stainless steel mechanical properties 
 Mechanical Properties: Hardness: Annealed ≤ 269HB; quenching and tempering, ≥ the 58HV mechanical performance: the internal stress (250 N/mm2) tensile strength (560 N/mm2) EL (18%) of HB (250) 
 Seven, 440C stainless steel heat treatment process 
 Heat treatment and microstructure specifications: heat treatment specifications: 1) annealing, slow cooling of 800 ~ 920 ℃; 2) quenching oil cooling of 1010 ~ 1070 ° C; 3) temper, rapid cooling from 100 to 180 ℃. Microstructure: the organization is characterized by a martensitic. 
 Delivery status: general delivery to the heat treatment, the treatment types specified in the contract; not indicated, according to the Steel Co., Ltd..