Use medium frequency induction heating machine to perform quenching and tempering heat treatment on connecting rods

The general manufacturing process route of quenched and tempered steel connecting rods is:

Forging, tempering, shot peening, hardness and surface inspection, correction, precision pressing, flaw detection, machining and finished product.

Many factories use forging waste heat quenching and then tempering instead of quenching and tempering. After tempering, hot correction is used instead of cold correction to reduce correction stress. Non-quenched and tempered steel connecting rods should be cooled under a controlled cooling curve after forging to obtain stable mechanical properties that can replace quenched and tempered steel.

Using a medium frequency induction heating machine to quench the connecting rod with forging waste heat can not only simplify the process and save energy, but also improve the cutting performance and mechanical properties.

Medium carbon steel forgings with w(C) of 0.40%~0.55% are usually quenched using a medium frequency induction heating machine for forging waste heat. The following points should be noted during mass production:

(1) The forging heating temperature is preferably 1100~1220℃. For example, the forging heating temperature of 45 steel can be selected in the range of 1150~1220℃.

(2) In actual production, the final forging temperature is the quenching temperature, which is generally 900~1050℃. During operation, attention should be paid to controlling the residence time between final forging and entering the oil fire to prevent the precipitation of ferrite.

(4) In order to prevent cracks caused by being left for too long after quenching, tempering should be carried out in time after quenching.

For mass production, induction heating using a medium frequency induction heating machine is an economical and effective method of heating blanks. Due to accurate temperature control, the final forging temperature can be ensured to be stable, which is particularly suitable for the forging waste heat quenching process.