What is the definition of spring?
It is a mechanical part that works by elasticity. Generally made of spring steel. It is used to control the movement of mechanical parts, mitigate impact or vibration, store and measure the force, and is widely used in machines and meters.
Because of the different uses of springs, people have to design them into different materials and shapes. Generally speaking, the raw materials of springs can be divided into two types, that is, steel wire springs and flat scroll springs made of steel strips. Steel wire spring can be divided into tension spring, compression spring, torsion spring, tower spring, cone spring, butterfly spring and various special-shaped springs. The scroll spring includes plane scroll spring, conical scroll spring, spring spring and spring coil.
The steel used to make springs is called spring steel. It should have high elastic limit, fatigue limit and toughness, so as to better adapt to dynamic performance such as vibration and impact or to be used under various complex static performance and variable stress conditions.
Spring steel can be divided into hot-rolled spring steel plate (wire) and cold-rolled spring steel plate (wire) according to its production method. Take the steel strip for the production of flat scroll spring as an example. The cold-rolled steel plate has uniform thickness and good toughness, while the hot plate has relatively uneven thickness and poor toughness. In the production of small flat scroll springs, spring springs, various spring pieces or small coil springs, we will try our best to select cold-rolled plates (wires) and conduct heat treatment after machining. In this way, the processed springs can be heated evenly and the hardness can be adjusted to the value we need. Many spring steels used for processing large coil springs will choose hot-rolled ones.
Spring steel can be divided into carbon spring steel and alloy spring steel according to different metal elements. Carbon spring steel is characterized by low price and wide application. After heat treatment, the fatigue limit is not lower than that of alloy spring steel. The disadvantage is that the hardenability and yield strength are low, and the spring with large cross section cannot be quenched during oil quenching, and it is easy to crack during water quenching. If the carbon content is increased, the strength and elastic limit can also be increased, but this will reduce the toughness of the steel itself, which is commonly known as "brittle" and brittle. At present, there are four grades of carbon spring steel in China: 65, 70, 75 and 85. Alloy spring steel is to add manganese, silicon, chromium, molybdenum, tungsten, vanadium and a small amount of boron to the material elements. These alloy elements can improve the hardenability of the steel. Manganese and silicon are dissolved in iron element to improve the strength. Chromium, tungsten and vanadium can improve the elastic limit and heat resistance of steel, and can manufacture important springs with large section and high yield limit.
Another kind of spring material is widely used in the application of flat scroll springs and compression springs, as well as in various springs and metal stamping parts. Its corrosion resistance is better than that of other steels. It is suitable for nitric acid and food factory equipment, and can also be used to make parts working at high temperature, such as gas turbine parts.
