When choosing gear materials suitable for the hard tooth surface DFY710 gear reducer, multiple factors need to be considered comprehensively. The following are the specific selection points:
Consider load conditions
In the case of light load, low speed or medium speed, low impact force and low accuracy : medium carbon steel can be used, such as Q235, Q275, 40, 45, 50, 50Mn, etc., and soft tooth surface gears are often made by heat treatment such as normalizing or tempering. The normalizing hardness HBS160-200, and the general tempering hardness HBS200-280.
In the case of medium load, medium speed, withstand certain impact loads and relatively stable movement : medium carbon steel or alloy tempered steel, such as 45, 50Mn, 40Cr, 42SiMn, etc., low-hardenable steel such as 55Tid and 60Tid can also be used. Hard toothed gears are made through high-frequency or medium-frequency quenching and low-temperature tempering, and the toothed surface hardness can reach HRC50-55.
In case of heavy load, high speed or medium speed, and subjected to large impact loads : low-carbon alloy carburized steel or carbonitrile co-penetration steel are selected, such as 20Cr, 20CrMnTi, 20CrNi3, 18Cr2Ni4WA, etc. After carburizing, quenching, and low-temperature tempering, the gear surface obtains high hardness of HRC58-63, and the gear core has high strength and toughness.
Focus on material performance
Hardness : The surface hardness of the gear material used in the hard toothed reducer must reach HRC45 or above to ensure its durability and wear resistance.
Strength : The gears will bear a large load when transmitting power, so choose materials with sufficient strength, such as 20CrNiMo, 40CrNiMo, etc. to avoid failures such as breakage.
Toughness : To ensure that gear materials have fracture resistance when impacted or twisted, high carbon content and appropriate alloy doping are usually used to improve toughness.
Fatigue strength : During use, the gear will experience fatigue fracture due to frequent stress and deformation, so it is necessary to choose materials with higher fatigue strength, and usually heat treatment is required to improve the fatigue strength.
Consider the heat treatment process
Carburizing and quenching : For gears that withstand heavy loads and require high surface hardness and good core toughness, materials that can be carburizing and quenching can be selected, such as 20CrMnTi, 20CrMnMo, 17CrNiMo6, etc. The surface hardness of the gear after carburizing and quenching is high, the contact strength and bending strength are high, and it is suitable for low-speed heavy-load gear transmission.
Nitriding treatment : For precision transmission gears or hard-toothed gears (such as internal gears) that have difficulty in grinding teeth, nitride steel, such as 35CrMo, 38CrMoAlA, etc. After tempering and nitriding treatment, the hardness of the toothed surface is as high as HV850-1200 (equivalent to HRC65-70), good thermal stability and certain corrosion resistance, but the hardened layer is thin and not impact-resistant.
Other factors
Processing performance : The selected materials should be easy to manufacture and process to reduce production costs and improve production efficiency.
Cost : On the premise of meeting the usage requirements, the cost of the material should be comprehensively considered and the cost-effective materials should be selected. For example, medium carbon steels such as 45 steel are relatively low in cost, while some special alloy steels are more costly.
