Quenching oil Introduction: Quenching oil is a process oil, used as a quenching medium. Quenching oil must have the following characteristics:

1) Good cooling performance is an important performance of quenching medium. Good cooling performance can ensure the hardness and qualified metallographic structure of hardened parts, and 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 Quenching oil for a long time in the harsh conditions of high temperature continuous operation, requires that the oil has good oxidation resistance, thermal decomposition resistance and anti-aging performance, in order to ensure the cooling performance and service life of the oil (quenching oil should be replaced or added regularly according to the need).

4) Low viscosity under the premise of ensuring the cooling performance and flash point of the oil, 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 easy to handle, no pollution to the environment, and make the quenched workpiece surface bright.

2. 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.

3) 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.