Hyperthermia unregulated body temperature elevation, the set point does not move, but due to thermoregulation disorders (such as damage to the thermoregulatory center), or heat dissipation obstacles (ichthyosis and the center caused by high ambient temperature, etc.) and abnormal heat-producing organs ( Such as hyperthyroidism), etc., the body temperature regulation mechanism cannot control the body temperature at a level compatible with the set point, Kunshan heat treatment is a passive body temperature increase; underheating is the phenomenon that the fluid is in an unsaturated state, that is, the fluid temperature is lower than the saturation temperature .

In vacuum heat treatment, there are often questions about overheating or underheating. So what exactly is overheating and what is underheating?

The overheating of the microstructure after quenching can be investigated from the rough mouth of the bearing parts of the roller fittings. But it is necessary to investigate the microstructure to accurately judge the degree of its overheating. If coarse acicular martensite is present in the quenching structure of GCr15 steel, it is a quenching superheated structure. The cause of the formation may be all overheating caused by too high quenching heating temperature or too long heating and holding time; it may also be due to the serious formation of banded carbides in the original structure, and the low-carbon area between the two bands forms part of the martensite needle-shaped thick, The constituent parts are overheated. In the superheat arrangement, the retained austenite increases and the dimensional stability decreases. Due to the overheating of the quenching mechanism and the coarse crystals of the steel, the resistance of the parts will decrease, the impact resistance will decrease, and the life of the bearing will also decrease. Severe overheating can even cause quenching cracks.

If the quenching temperature is too low or the cooling is not good, a tortite structure that exceeds the standard rules will occur in the microstructure, which is called underheating structure, which reduces the hardness and wear resistance sharply, which affects the bearing life of idler parts.