The Properties of a Spring Steel Coil

The material used for coil springs has to be able to withstand substantial twisting and bending without distortion. Various metals are used, but the most common is spring steel.

A key characteristic of steel is its modulus of elasticity in tension and shear. This varies with temperature and must be taken into account in the design of a spring.

Strength

A spring needs to be able to store and release mechanical energy over time. To do this, it has to have a high combination of tensile strength and yield strength, as well as resistance to stress relaxation. Alloys that are referred to as spring metals naturally possess these properties. Examples include medium and high-carbon steels. The tensile strength of spring steel is increased by heat treatment. Alloys that are heat treated also have improved ductility, fatigue resistance and corrosion resistance. One common alloy that is used for coil springs is nickel chromium iron, such as Inconel 600. This type of alloy has oxidation and corrosion resistance, high strength at temperatures up to 1800degF or 740degC and good resistance to chloride stress cracking. Nickel based alloys are also non-magnetic and can be used in gyroscopes and chronometers because they are not susceptible to magnetic field interference.

The yield strength of a spring steel coil is also enhanced by work hardening, which is achieved by rolling and reducing the thickness of the material. This process increases the tensile strength of the material by increasing its hardness and modulus. This can be done for all spring alloys, but is particularly useful for austenitic stainless grades such as 304. When this is done, it can also increase the tensile strength by as much as 40%.

Elasticity

The elasticity of a spring steel coil is defined as its ability to absorb and release mechanical energy. This property is vital to the performance of metal springs, which need to withstand significant amounts of stress for long periods of time. Elasticity is determined by the material type used to produce a spring. It is also influenced by the operating conditions of the spring.

Coil springs can be made using different types of metal. Most commonly, they are produced from high or medium carbon steels. These alloys have a high combination of tensile and yield strength, which means they can handle considerable stress for a prolonged period of time. Other popular metals for coil springs include chromium vanadium steel, chromium silicon steel and various grades of stainless steel. These materials can handle a wide range of temperatures and resist corrosion.

Elasticity is also affected by the spring’s pitch and coil diameter. A smaller pitch allows more coils to be placed in a given length, which increases the spring’s strength. Conversely, a larger coil diameter creates a less flexible spring.

The elasticity of springs can be further improved through the addition of elements like nickel, copper and vanadium. These compounds are particularly effective for applications that require corrosion resistance or spring steel coil electrical conductivity. Copper, for example, has a Young’s modulus of about 110-128 GPa, which makes it an excellent choice for springs that must repeatedly store and release mechanical energy.

Corrosion Resistance

The corrosion resistance of spring steels is a critical factor in their suitability for use. There are several mechanisms of corrosion that can affect the performance of coil springs. These include uniform corrosion, pitting corrosion and stress corrosion cracking. These phenomena can be mitigated by ensuring that the metal is protected with a suitable coating.

Coatings can be applied in various ways, including Tinplate steel coils supplier spray painting and dipping. They can also be electroplated onto the springs. The choice of coatings depends on the specific requirements of the application and the environmental conditions to be encountered. Some coatings may increase the life of springs, but they must be chosen carefully to avoid hydrogen embrittlement.

Other methods of improving the corrosion resistance of spring steels include shot peening, heat treatment and stress setting. These procedures expose the steel to stress and heat for varying periods of time to prepare it for service. They can also reduce the size of the first phase of relaxation and establish a residual stress system that resists subsequent influences on relaxation.

Chrome-vanadium steel is the most popular alloy spring material for highly stressed, long life and impact/shock loading applications. It is available in diameters from 0.8 mm to 12 mm and can be used for temperatures up to 220 deg C. This alloy does not normally change dimensions under heat and can be plated.

Weight

Spring steel is a specific type of steel designed for its high yield strength, elasticity, hardness, and resilience. This makes it suitable for use in coil springs, automotive suspension components, and mechanical parts that must withstand cyclical stresses. Its high tensile strength and fatigue resistance also make it ideal for creating clips and fasteners that hold things together.

When manufacturing coil springs, there are several different types of steel wire available. Stainless steel wire is commonly used as it is not susceptible to corrosion in humid or corrosive environments. The most common type of stainless steel wire is Stainless Steel 302, but there are other grades available such as Stainless Steel 17-7.

The spring steel is heated and then coiled around a mandrel or by using a computer numerical control (CNC) machine that can efficiently feed and wind the coils. Once the coils are formed, they must be rapidly cooled to prevent oxidation and to harden the steel. This process is known as quenching and can be completed by using various methods, including oil.

To calculate the weight of a spring, start by measuring the outer diameter and length of the coils. Enter these variables into a spring coil weight calculator and you will get a rough estimate of the weight of each coil. Remember to take into account the size of the mandrel and any additional material added to the coils when calculating the weight.