The workpiece is quenched and heat treated using a high-frequency induction quenching machine, what impact does the quenching temperature have on the workpiece?

Nowadays, more and more workpieces are quenched and heat treated using high-frequency induction hardening machines. In the entire quenching process, the quenching temperature is very important and has a great impact on the workpiece. Today, the editor will briefly tell you about the effects of quenching temperature on workpieces.

The influence of quenching temperature on the workpiece is multifaceted, but in summary, its influence is mainly reflected in the following two aspects:

1. The effect of quenching and tempering temperature on hardness. When using a high-frequency induction quenching machine for quenching heat treatment, the quenching heating temperature increases, and the quenching hardness of the MC5 steel block also increases, reaching a maximum value of 64HRC when quenched at 960°C. For steel blocks quenched at the same temperature and tempered step by step, the hardness will drop gently by 4-5HRC as the tempering temperature rises from room temperature to 280°C. Among them, the hardness after 960℃ quenching + 200℃ tempering is 61.5HRC, and the hardness after 960℃ quenching + 280℃ tempering is 59HRC.

2. Effect of quenching temperature on steel grain size. From the metallographic analysis, it is known that the holding time is 20 minutes. The quenching structures at 880°C and 950°C are mainly cryptocrystalline martensite, and more acicular martensite appears in the quenching structure at 1010°C. The higher the quenching temperature, the coarser the grains. The grains quenched at 880°C are finer, the grain boundaries are not obvious and cannot be graded, and there are still a large number of carbides. The grain size quenched at 960°C is uniform, the grain boundaries are clear, and the grain size is 11.5. The grains quenched at 980°C have grown somewhat, are uniform in size, and have a grain size of 11. The grain size quenched at 1010°C is larger and uneven in thickness. The coarse grains are grade 8.5 and the fine grains are grade 10.5. Analysis shows that the quenching temperature of 880°C is too low and a large amount of carbides are not dissolved. The quenching temperature of 1010°C is relatively high and the grains are relatively coarse. Therefore, quenching temperatures that are too high or too low are not advisable.

From the above description, we can see that the impact of quenching temperature on the workpiece is very large. Therefore, in the subsequent heat treatment process, we must grasp the quenching temperature of the workpiece so that the produced workpiece meets its working requirements.