Springs are one of the most important parts in machines and instruments, mainly in shock, vibration or periodic bending, twisting and other alternating stresses, is used to absorb shock energy, reduce vibration and shock, or store energy to drive the machine parts. Commonly used a variety of springs have a circular section of small springs, spring rings, valve reeds, automotive reeds, trailer springs, force-testing springs and heat-resistant springs and so on. Most springs are heat treated to achieve product performance requirements. In order to improve the mechanical properties of the spring, the large cross-section (thickness or diameter 5-40mm) steel (round steel, flat steel, etc.) after hot rolling is made by roll, then quenched back-fire treatment;
In the heat treatment quenching process, it is hoped that by controlling the cooling rate of spring products to obtain a high and uniform hardness and sufficient hardening layer depth, while reducing deformation and preventing cracking. To this end, a series of quenching media have been studied and developed to meet the needs of the development of the mechanical industry, of which more is still used quenching oil. Although there are many claims that polymer quenching media can completely replace oil, in fact, due to certain characteristics of oil and the irreplaceability under certain conditions, it is absolutely impossible to completely replace for a considerable period of time.