New developments in spring materials Si-Cr steels have been widely used in ferrous metal valve springs and suspension springs. To improve fatigue strength and relaxation resistance. Adding V, Mo in the Si-Cr steel. The hot-formed springs are generally large in size. To ensure large cross-section springs with high elasticity and excellent overall performance, two types of alloying elements are added. The purpose of adding these elements is to stabilize the state of the tissue so as to improve the resistance and relaxation resistance of the spring material to the slight plastic deformation. Alloying elements and acting alloying elements Active elements that increase the hardenability of Si, Mn, Cr, Ni, Mo, W, VB, Ti, Zr, Nb, Re, and hardenable microelements In 1999, BMW researched 11 types of projects. High-stress, high-strength spring steel, comparing the relationship between the size, distribution, and fatigue life of various types of inclusions. After detailed statistics and analysis of various failure modes and fatigue fracture mechanisms, a database of fatigue properties of high-stress springs was formed, and the most influential factors on fatigue performance and the ultimate cracks that did not destabilize under certain high stress conditions were found. The results, such as length, provide reference for the future use and selection of ultra-pure spring steels, and will be applied to future automotive springs. Spring design of non-ferrous metal materials has begun to develop to high stress. Generally, the stress on clutch springs like Polaris and Ski-Doo has exceeded 70% of the tensile strength of materials. At this time, high-stress spring steel has only slight surface. In the presence of scratches or corrosion spots, stress fracture occurs. The sensitivity to these surface defects is referred to as the /notch sensitivity. 0. In recent years clutch spring designs have surpassed the limits of spring steels and turned to Ti alloys with low notch sensitivity to make springs. As one of the best spring materials, the non-ferrous alloy Ti alloy has the characteristics of light weight, small elastic modulus, good corrosion resistance, and is widely used. Its tensile strength is lower than that of steel, and its elastic modulus is also more than half that of steel. This means that with a slightly larger diameter Ti spring, it will be twice as large as the steel spring, while reducing the weight and volume by half. The notch sensitivity of Ti alloy springs is very small. When traveling in the desert, the whole spring can have large rock pits, and it can still work without losing performance. Non-metallic materials Non-metallic materials for springs are mainly vibration-proof rubber and reinforced plastic. The shape of the rubber spring is not limited. The stiffness in each direction can be freely selected and can withstand loads from many aspects. Rubber can be used to make air springs. Air springs produced by the world's first Fire-stone air spring company have applications in trucks, trailers, new Lincoln City vehicles and Navigator. Reinforced plastics have the characteristics of light weight, high specific strength, more energy absorption than spring steel, corrosion resistance, etc., and have been used to manufacture plate springs and disc springs. Currently used to make plastic springs are mainly thermoset resins plus glass fibers or other fiber-reinforced composites. Glass fiber-reinforced plastic (GFRP) plate springs are widely used in suspension suspensions in the UK, Japan, and the United States. With the same mass of GFRP and spring steel, GFRP is capable of storing elastic deformation energy 7 times that of spring steel. That is to say, in the case of the same stiffness and plate width, the spring made of GFRP deforms and bears the maximum load. 1.7 times, but the quality can be reduced to 41% of steel. At present, it has successfully developed a stronger carbon fiber reinforced plastic (GFRP) suspension spring, the quality of which is 80% of the metal leaf spring. In the cold coil/hot coil and induction treatment fatigue tests, the maximum stress occurs mostly on the surface of the spring, so the surface quality of the spring has a great influence on the fatigue strength. Different winding methods will result in different surface conditions. The smaller the surface roughness of the general material, the smaller the stress concentration and the higher the fatigue strength. When the spring is hot-rolled, the surface of the spring is roughened due to oxidation, and decarburization occurs, which reduces the fatigue strength of the spring and adversely affects the fatigue life. Therefore, the coil springs with simple shapes adopt cold coils. In addition, the spring steel used for cold coils is manufactured after induction hardening and induction tempering. The required mechanical properties have been achieved before leaving the factory. Cold rolls only change shape and do not improve performance. One of the benefits of rapid thermal sensing processing is grain refinement. Grain refinement is the only heating method that does not sacrifice strength and improves toughness. The conventional electric furnace heating method generally has a grain size of up to 8 and can be refined to 10 or more by induction heating. Slewing Bearing,Ball Joint Spherical Bearing,Pillow Ball Rod End Bearing Bearing Co., Ltd. , http://www.china-bearing-directory.com