How to choose heat treatment quenching oil?

1. Hardness requirements and deformation effects

The critical cooling rate of different materials is different, the hardness requirements of the parts are also different, and the accuracy and control deformation requirements of the parts are also different. quenching oil. After the quenching oil is determined and selected, various control measures such as quenching temperature, oil temperature, stirring and cooling speed and time, and oil feeding time are adjusted by controlling the quality and selection of raw materials (parts data and oil product data), combined with the tempering after quenching. Process, tempering temperature, and tempering time parameters are tested to meet the hardness requirements and metallographic requirements of the parts. After the parameters of the heat treatment process are adjusted and controlled, and the heat treatment is in harmony with the machining, the heat treatment deformation is controlled within a reasonable range.

2. Selection method of heat treatment quenching oil

From the beginning of the heat treatment and quenching process to the selection criteria of quenching oil: the cooling function of quenching oil must reach the required hardness (fast cooling speed) and never allow cracks, and control the heat treatment deformation within a reasonable minimum range ( A good combination of cooling speed requirements) is found between the two, and this contradictory cooling speed requirement is a requirement for different temperature ranges, which provides a direction for the research and development of heat treatment quenching oil. In view of the constraints of testing conditions, in the past, in the heat treatment production practice of the factory, we could only make a rough selection of the quenching medium based on general knowledge and experience and then verify it with experiments.

The wide application of the cooling characteristic instrument provides a detection tool analysis method, which helps us optimize the scientific selection of quenching oil and analyze and compare. We can conditionally test or outsource testing or require oil companies to provide quenching oil cooling characteristics test data reports to provide a scientific basis for the selection of quenching oils.

According to the production practice and the company's quality policy, the quenching oil that meets the cooling performance requirements should be compared and compared with other technical indicators, and the most suitable ones are selected. The stability and oxidation resistance of quenching oil, the repeatability and reproducibility of cooling function, brightness, safety, and cost are all factors that need to be considered.