Carp pliers use high-frequency induction heating power for heat treatment. How much do you know about its process?

Carp pliers are widely used hardware tools. QB/T2442.4-2007 stipulates that they are made of 50 steel, the hardness of the blade is 46-56HRC, and the other hardness is 25-35HRC. Many manufacturers use high-frequency induction heating power to heat treat it to improve its hardness, wear resistance and service life to meet their technical requirements. Today, the editor will tell you about the high-frequency heat treatment process of carp pliers.

1) Annealing. There are mainly two types of carp pliers, 6in and 8in (lin=25.4mm), and some have hexagonal wrenches at the end. It is formed by die forging with a diameter of 16mm50 steel. After forging, a high-frequency induction heating power is used for annealing heat treatment. The process is 820-840℃x3h furnace cooling to 200℃ air cooling. In order to prevent decarburization, a layer of sawdust is sprinkled on the surface of the workpiece, which achieves good results. In this way, the annealed workpiece will not be decarburized, but will also be beautiful and smooth, with a hardness of 179-208HBW.

2)Quenching. Use a high-frequency induction heating power supply for quenching heat treatment. During quenching, place the jaws downward and heat the entire body at 810-820°C x 4.5 minutes. During cooling, the jaws first move on the liquid surface for 4-5 seconds to ensure that the jaws are hardened and then fully immersed. Cooling with coolant, tempering at 300-320℃x2h. After this process, the edge hardness is 51-56HRC, but the tail hardness is not satisfactory. If the operator is not skilled in technology, it will be difficult to implement. Quality is ensured with two quenchings and two temperings. That is, the handle is first quenched at 800-810℃x4min, induction tempered at 500-520℃x2h and then water-cooled. After quenching the blade, 800-820℃x4.5min, heating just beyond the round hole, all liquid is poured in when cooling, tempering at 300-320℃x2h, although this method is a bit troublesome, but the process is stable. You can also use a simple method: quench and heat to the jaws, dip the handle tail for 5-6 seconds before taking it out of the oven, and then cool it as a whole.

The heat treatment process is a key factor affecting the quality of the workpiece's heat treatment. Therefore, it is very important to master the heat treatment process of the workpiece. Today, the editor briefly introduces to you the high-frequency heat treatment process of carp pliers. I hope you like it.