Hardened steel common materials heat treatment procedure

Because of excellent use performance of hardened steel widely used in transportation, metallurgy, wind power, mold, construction machinery and other fields. Different industries using 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 after the heat treatment process will obtain excellent usage performance. such as automobile parts gears, gear shafts, crankshafts, etc. Gearbox require high performance, so often use 20CrMo or 20CrMoTi as for the main material of gear. 20CrMo gear heat treatment process includes: normalizing, carburizing, quenching, tempering.

Normalizing: 20CrMo gear normalizing temperature at 930~950℃, in order to promote austenite homogenization, increasing austenite super cooled stability;

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.

Quenching and tempering: quenching temperature between 820~850℃, after heat preservation using oil cooling, 180℃ low tempering.

Through hardened steel gear hardness after heat treatment at HRC55 or more, not only to obtain a higher hardness, strength, wear resistance, but also strong fatigue resistance and strong fracture resistance, and can working at high speed state.

2. Bearing industry common materials heat treatment process

Because of some bearing operating in harsh environments, on the processing performance of the bearing demanding, it is required to have good performance and long life. Therefore we often use 40Cr or GCr15 as for the main material of bearing. Bearing through heat treated to obtain a higher hardness, wear resistance and good toughness, fatigue resistance. Bearing heat treatment process including: annealing, quenching, tempering.

Annealing: GCr15 steel annealing temperature is 780~810℃,after forgings a special heat treatment, the annealing temperature should reduce 10~20℃.

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, hardened steel bearings hardness in general HRC60 or more, not only high hardness, good wear resistance, and service life is improved.

3. Hardened steel parts machining after the heat treatment

Hardened steel hardness is over HRC50 after heat treatment, such as automotive gear hardness is HRC58~63,GCr15 bearing hardness is HRC60~62, which is a big problem for machinery manufacturers. It is necessary to ensure the quality of hardened steel parts, but also to ensure the efficiency of hardened steel parts. The initial grinding can not meet requirements of processing efficiency of the machinery manufacturers, can only come from other places to find a solution.

With the continuous development of the cutting tool industry, eventually developed hard turning cutting tool material, which can effectively solve the problem of low grinding efficiency. Hard turning cutting tool materials have coated carbide cutting tools, ceramic cutting tools and cubic boron nitride cutting tools, simply select the appropriate cutting tool materials to improve the processing efficiency of hardened steel parts.

Halnn superhard developed non-metallic adhesive cubic boron nitride cutting tools, for over HRC45 hardened steel parts can be effectively solve the problem of low processing efficiency.

Processing automobile gear inner bore, end face optional BN-H20 grades and BN-H21 grades CBN cutting tools (intermittent machining conditions);

Processing GCr15 bearing inner bore, cylindrical choose BN-H11 grades CBN cutting tools (continuous cutting);

Processing large pieces of hardened steel gears gear face, optional BN-S20 grades CBN cutting tools (strong interrupted cutting conditions).

If you have more questions ,please feel free to contact with us halnntools@gmail.com ,whatsapp:+8618695866134