Process analysis and implementation key points of heat treatment of bicycle chain using high-frequency induction quenching machine

The bicycle chain is the main component that transmits power. On the one hand, it is subject to abrasive wear, and on the other hand, it produces impact due to pedal power and road bumps. Therefore, the chain should have high surface hardness and wear resistance, and at the same time it should have A certain degree of tensile strength and ability to resist plastic deformation, so a certain degree of toughness is required. For this reason, many manufacturers use high-frequency induction hardening machines to heat treat chains, with good results.

The heat treatment of the chain consists of two parts. One part is chemical heat treatment (including quenching and tempering) to obtain the required hardness and toughness. The other part is surface treatment, which aims to have good corrosion resistance and extend its service life. Shot peening is to spray steel shot of a certain diameter on the surface of the part at a high spray speed to form uniform small pits. , to improve the surface fatigue strength of the chain.

According to the working characteristics and technical requirements of the chain, it must have a certain hardness and good strength, and can withstand tensile force. It is made of low-alloy structural steel and is quenched with a high-frequency induction quenching machine and then tempered at medium temperature. , a troostite structure is obtained with a hardness of 71-74HRA, which can meet its working needs. When 45 steel is used for quenching and tempering (quenching and ten high-temperature tempering), the hardness is controlled within the range of 197-241HBS (or 25-35HRC).

The surface blue treatment of the chain is to form an oxide film to improve the oxidation resistance and corrosion resistance of the surface. This process can be performed together with tempering or independently, and the temperature is basically the same as the tempering temperature. This not only solves the problem of surface treatment and chain tempering, but also gives a good appearance.