What Is Quenching Oil?

1) Good cooling performance is an important performance of quenching medium.  Good cooling performance can ensure that hardened parts have a certain hardness and qualified metallographic structure, and can prevent deformation and cracking of parts.  

2) When quenching with high flash point and flash point, the temperature of oil will rise instantly, so the quenching oil should have a higher flash point and flash point.  Generally, the flash point should be 60-80 degrees higher than the oil temperature.  

3) good thermal oxidation stability of quenching oil at high temperature for a long time continuous operation under the conditions of use, require oil has good oxidation resistance, thermal decomposition resistance and anti-aging performance, to ensure the cooling performance and service life of oil (quenching oil should be periodically according to the need to replace or add)

4) low viscosity in guarantee under the premise of oil cooling performance and flash point,  The viscosity of the oil should be as small as possible, so as to reduce the carrying loss and facilitate the cleaning of the workpiece.  

5) Too much water in oil with low moisture content will affect the heat treatment quality of parts, resulting in soft spots, quenching cracks or deformation of parts, and may also cause oil spatter and accidents.  Therefore, it is generally stipulated that the water content of quenching oil shall not exceed 0.05%.  

6) Other characteristics In addition to the above characteristics, quenching oil should be non-toxic, tasteless, easy to handle, no pollution to the environment, and make the quenched workpiece surface bright.  

 Classification of quenching oil

mineral oil forms special quenching oil with different characteristics and uses due to different composition and refining methods.  According to the requirements of use (including cooling speed, temperature, brightness, etc. 

1) Common quenching oil Common quenching oil is one of the common oil used for heat treatment, cooling speed is relatively slow, made from paraffin-based lubricating oil refining, adding coolant and antioxidant.  

2) Super (high) speed quenching oil overspeed quenching oil cooling speed is faster than fast quenching oil.  The oil is made by adding refrigerant, detergent and antioxidants to a refined paraffin-based lubricant.  When the oil temperature is 800, its characteristic temperature is not less than 585, and the cooling time to 400cC is shorter than that of quick-quenched oil.  In production, it is mainly used for bearing parts with large cross section and deep hardening layer.