Oil quenching
Oil, next only to water, is the most widely used quenchant because of its versatile quenching performance. Global quench oil consumption per year is around 50 million to 100 million gallons. As its quenching mechanism and cooling curves are well suited to the time, temperature and transformation (short for TTT), and continuous cooling transformation (short for CCT) diagrams of different types of steel.
Water quenching
Because of the following characteristics, water quenching steel is considered to be harder than oil-quenched steel.
1.The thermal conductivity of water is higher than the thermal conductivity of most oils. The faster the cooling rate, the higher the hardness in steels.
2. Specific heat of water is higher than most common oils.
3. Compared with oils, water has lower viscosity.
4. Density of water is higher than that of oils.
All the above points make water a higher convection efficiency and thus quench efficiency compared to oils.
Salt quenching
Molten salt has been applied for quench medium for more than half century thanks to its wide operating temperature range, from 300°F to 1,100°F. What makes salt quenching unique is that there is no vapor stage in the beginning as other quench medium. The high thermal conductivity and the addition of water contribute to the fast quenching rates. For example, salt quenching is the only choice when the process like austempering needs high temperature. Salt quenching excel in achieving the max hardness with min deformation. Also, salt bath quenching is environmental-friendly and economical in the long term, and it is getting more widely used this years.
YT components is furnished with oil quenching furnaces and salt quenching line. Our team of experts are able to provide superior solution for your customized heat treatment and deliver the best quality and service.