1. Introduction of high temperature tempering of spring
1. Operation: The tempering temperature is 500-680℃, and the sorbite structure is obtained after tempering. Quenching + high temperature tempering is called quenching and tempering treatment, which can obtain comprehensive mechanical properties with good strength, plasticity and toughness. The disadvantage of secondary hardening of certain high-alloy steels (such as high-speed steel) with secondary hardening effect is that the process is more complicated. While improving the plasticity and toughness, the strength is reduced. At present, it can be replaced by thermomechanical treatment in some places Quenching and tempering treatment, ductile iron austempering instead of 45 steel quenching and tempering (Note: *Deformation heat treatment: After the steel is heated and austenitized and homogenized, it is quickly cooled to the temperature selected according to the needs, and the comparison is carried out when it has not been decomposed and transformed. A large amount of plastic deformation, and then quenching and tempering while it is still austenite to obtain tempered martensite. This thermal deformation processing is followed by a combined process of quenching and tempering treatment, and normal quenching and tempering By comparison, higher strength can be obtained at the same level of ductility and toughness).
2. Application: Widely used in various important structural parts, especially connecting rods, bolts, gears and shafts that work under alternating loads. Not only can it be used as the final heat treatment of these important parts, but also often The preselected heat treatment of some precision parts such as screw rods, etc., to reduce the deformation in the final heat treatment and provide a organizational basis for obtaining better final performance.
2. The effect of the spring after high temperature tempering
1. Operation: heating is slightly lower than the tempering temperature of high temperature, and then slowly cooled to below 300℃ after heat preservation.
1) The purpose of aging is to further eliminate internal stress and stabilize the size of the workpiece after quenching.
2) It is often used to process precision workpieces that require no deformation in shape, such as precision bearings, precision screws, bed, box, etc.
3) Low temperature aging is actually low temperature supplementary tempering