Heat treatment process of hardened steel
The heat treatment process of hardened steel and used cbn insert Because of excellent use performance of hardened steel, and was widely used in transportation, metallurgy, wind power, mold, construction machinery and other fields. Different industries use different materials, heat treatment procedures are also not the same. Here's a brief description about heat treatment process aiming at different industries of hardened steel materials. 1.Transportation industry common materials heat treatment process Some automobile parts which after heat treatment will obtain good usage performance, such as automobile parts gears, gear shafts, crankshafts, etc.. Gearbox require high performance, so it often use 20CrMo or 20CrMoTi as for the main material of the gear. The heat treatment process for machining 20CrMoTi includes: normalizing, carburizing, quenching, tempering. (1)Normalizing: Normalizing temperature at 930-950 ℃ , in order to promote austenite homogenization, increasing the stability of austenite supercooled; (2)Carburizing: Gas carburizing, at a temperature of 900-920℃, to 0.15-0.2mm/h calculate heat preservation time, the heating temperature does not exceed 920℃, in order to avoid coarse grains; (3)Quenching and tempering: Quenching temperature will be 820~850 ℃ , after heat preservation using oil cooling, 180℃ low tempering. Though the hardness of hardened steel gear after heat treatment will be HRC55 or more, it not only can obtain a higher hardness, strength, wear resistance, but also get strong fatigue resistance and strong fracture resistance, and can working at high speed state. 2. Bearing industry common materials heat treatment process Because there will be some bearing operating in harsh environment, it also required excellent performance and long lifetime. So we often use 40Cr or GCr15 as the main material of bearings. Bearing which after heat treating will obtain a higher hardness, well wear-resistance and good toughness, fatigue resistance. Bearing heat treatment process including: annealing, quenching, tempering. (1)Annealing: GCr15 steel annealing temperature is 780~810℃, after forgings a special heat treatment, the annealing temperature should reduce 10~20℃. (2)Quenching and tempering: GCr15 martensite under normal circumstances, the quenching temperature is about 840℃, generally not more than 850℃. The tempering temperature is controlled at 150~160℃ can meet the requirements. After heat treatment, the hardness of the hardened steel bearings will be about HRC60 or more, not only high hardness, good wear resistance, and service life is improved. 3. Machining Hardened steel parts after the heat treatment The hardness of Hardened steel is over HRC50 after heat-treatment, such as automotive gear hardness is HRC58-63, GCr15 bearing hardness is about HRC60-62, which will be a big problem for machinery manufacturers. It is necessary to ensure the quality of hardened steel parts, but CBN Insert BN-H11,BN-H20,BN-H21,BN-S20