Spring steel is steel that is used specifically for the manufacture of springs and elastic elements due to its elasticity in the hardened and tempered state. The elasticity of steel depends on its ability to deform elastically, i.e. within a defined range, the ability to deform elastically so that it can withstand a certain load without permanent deformation after the load is removed.
Comprehensive properties of spring steel, such as mechanical properties (in particular, elastic reduction, strength limit, elastic reduction performance ratio of bending strength, tensile properties)) To meet the above physical properties, spring steel has excellent metallurgical quality (high drug and homogeneity), good metallurgical properties, low temperature resistance, oxidation resistance and other properties. surface quality (strict control of surface defects and decarburisation), precise shape and size
Spring steel has hot rolled steel, cold drawn steel, cold rolled steel strip and so on. The smelting of spring steel is important and must ensure excellent metallurgical quality, not only to ensure accurate chemical composition, but also to ensure high purity, low sulphur, low phosphorus, oxygen, nitrogen content, uniformity of steel and good stability. The metallurgical quality of spring steel should reach the level of quality steel and quality steel
The surface quality and dimensional accuracy of the spring steel has a significant impact on the performance and life of the spring. As the surface of the spring steel in the delivered condition is no longer machined in addition to the surface shot peening, i.e. the working surface of the finished spring, the various defects on the original surface are also left to the spring. The surface requirements for spring steel are therefore very high, with very strict limits on decarburisation, cracking, folding, scarring, inclusions and delamination. Various surface defects can lead to premature damage and shorten the spring’s service life.
The strength and stiffness of the finished spring is proportional to the third and fourth power of the diameter of the wire, for example, and small changes in the diameter of the wire can lead to large fluctuations in spring performance, so the shape and dimensional tolerances of the steel need to be strictly controlled. The processing of spring steel deformations (hot rolling, cold rolling, cold drawing etc.) is therefore very important and must be taken very seriously.
Hot rolled spring steels are available in round, square and flat. The steel is highly demanding and can be delivered in hot-rolled quality or after heat treatment to ensure that it does not exceed the regulations and to facilitate the production of elasticity. Material production, the full range of elastic materials can be made after heating at about 50 ℃ of the comprehensive mechanical properties.
Due to the large cross section size of hot rolled material, the grade with sufficient hardenability should be used to ensure that the core is thoroughly quenched. If there are non-martensitic transformation products, such as ferrite, bainite, etc. in the heart, the performance after tempering will be reduced, especially the fatigue performance.
Cold drawn (rolled) spring steel includes steel wire and strip. The surface quality and dimensional accuracy requirements of this steel are particularly stringent. The production process for steel wire has two types of oil quenching and cold drawing.
Oil quenched steel wire is cold drawn to the required size and then heated, oil quenched and tempered in a lead bath, so the steel wire factory already has the required mechanical properties, made after the spring as long as the tempering, stress relief can be used. The advantage is that the performance of the whole batch is uniform, stable, straight and good, suitable for mass production, can manufacture a variety of important springs, especially valve springs. The grades are 65Mn, 50CrVA, 60Si2Mn, 55CrSi, etc.
Alloy spring steel wire can also be cold drawn delivery, or after annealing, normalizing, tempering treatment after delivery, made of spring and then quenching, tempering. Its performance is not as uniform as oil hardened steel wire, stable, low production efficiency, high cost, mostly used for small batch spring production.
In addition, high frequency induction heating has recently been studied for processing high strength spring wire. The cold-drawn wire is tempered on a continuous induction heating device, which has a uniform and fine internal organisation and significantly better plasticity, toughness, elasticity resistance, fatigue limit and fracture toughness than conventional steel wire.
This steel wire has been produced in the United States, Japan, manufacturing cars, motorbike suspension springs, engine valve springs, trucks, trailers and other emergency brake springs and a variety of high-strength mechanical springs, the use of satisfactory results. In addition, induction heating treatment is also applied to the production of spring flat steel.
There is also a steel wire production process, lead bath isothermal quenching. After austenitizing, the steel was isothermal in lead bath to generate fine pearlite structure, and then cold drawn to the specified size. The mechanical properties of steel wire can be controlled by adjusting the carbon content and cold deformation of steel wire. After spring making, there is no need for heat treatment, as long as the processing stress can be eliminated. This process is used to produce carbon steel wire, but there are a few alloy steel wire (such as 65Mn).
Cold rolled spring steel strip is also generally supplied cold rolled or annealed, made of spring and then quenched and tempered, or tempered only to eliminate processing stress.
Spring steel and manganese steel which is better for knives
High manganese steels are more suitable for use in post-processing materials. High manganese steel is a wear resistant steel designed for heavy industrial grinding, quarrying, mining, coal industry, processing, surface quality
Manganese steel castings are mostly made using sand casting process solutions. Sand casting is widely promoted due to its mature technology and high production efficiency. Special castings are also used. Special casting refers to sand casting of casting materials, forming methods, metal liquid filling forms and metal solidification conditions and other aspects of the sand casting methods have significant differences with the casting.
Spring steel refers to the manufacture of various types of springs and other elastic components of special alloy steel. According to the performance requirements, use conditions can be divided into ordinary alloy spring steel and special alloy spring steel.
Spring steel has excellent all-round properties. Spring steel has excellent metallurgical quality (high purity and homogeneity), good surface quality (strict control of surface defects and decarburisation) and accurate shape and dimensions.
The most important feature of manganese steel is that under strong impact and extrusion conditions, the surface layer rapidly process hardening phenomenon, so that the heart still maintains the good toughness and plasticity of austenite, while the hardened layer has good wear resistance.
Firstly, improvements and updates to the original functional state.
Second, excessive vibration of the car, head-butting from side to side when braking and irregular tyres.
three, excessive leaning of the car when turning or otherwise.
Fourth, many housing failures or cause oil leakage from the damper, affecting the performance of the damper; oil leakage is the case of damper problems, oil leakage has, among the most common causes of the most likely consequences