Manufacturing process and material of compression spring
The manufacturing process and materials used for manufacturing compression springs will be discussed here.
1.Manufacturing process of compression spring
The manufacturing process for manufacturing compression springs includes:
Number of turns
Winding first sends the wire into the straightening process. If the wire enters the coiler straighter, the coiler will produce better parts. In this step, the CNC machine with preprogrammed settings modifies the arm and spindle to produce the spring and adjusts the factors including the free length, pitch and coil of the spring. When the machine makes the spring, the high-speed camera will record the image, enabling us to measure each component and adjust it as needed to keep it within the tolerance range. After the machine cuts the spring from the wire, the product will enter the process of reducing stress.
The wire is subject to stress during winding, which makes it brittle. We solve this problem by heating the spring in the oven, which will cause the coil to solidify into a new shape and generate a metal link. Within the predetermined time, the oven will keep the temperature of the coil at an appropriate level, and then slowly let the coil cool.
According to its expected application, the wire rod will undergo several finishing operations after the stress relief process. The completion spring converts it from its original form to a specific tool, thus enhancing its potential application. The following are some procedures involved in spring finishing:
Grinding: The designer must grind the ends of the springs flat to make them easier to adhere to other surfaces.
Strength shot peening: Despite extensive use and frequent bending, strength shot peening can still prevent metal fatigue and steel fracture.
Setting: The designer compresses the spring thoroughly to make all its coils contact to permanently establish its expected length and spacing.
Coating: The designer can apply non-corrosive coating on the spring, immerse it in liquid rubber, or coat it with another metal, such as zinc or chromium, to avoid corrosion.
Packaging: designers develop special spring packaging, such as bulk packaging with boxes or plastic bags.
2.Materials used for manufacturing compression springs
The steels that can be used to manufacture compression springs include stainless steel, hard drawn steel, steel wire and spring steel. Compared with the spring with smaller wire diameter, the compression spring with wider wire diameter may bear greater service pressure. Generally speaking, the larger the line, the stronger the spring. The decrease of the coil diameter can also increase its strength.
Stainless steel is ideal for these applications because it can resist corrosion even when exposed to moisture and chemicals. Steel is elastic and firm; It can withstand continuous use without cracking.
In addition to spring steel, other types of steel and even plastic can be used to make springs. However, the incorrect matching of the spring and its application may lead to early failure, thus damaging nearby objects and, in some cases, causing injury to people.
It is important to select the appropriate material for the spring combination. Correct selection of spring will maximize its effectiveness and service life. For spring material, steel alloy is usually used. Low-carbon, high-carbon, stainless steel, chromium-silicon and chromium-vanadium alloys are common alloys. Some metals, such as titanium, phosphor bronze and beryllium copper alloys, are occasionally used as springs. Ceramic material is used for coil spring in high temperature environment.
Due to its high carbon steel composition, piano wire can be used for high-strength applications, including fitness equipment, lawn and gardening tools, and household decoration products. The wire made of piano wire has a modulus of elasticity of 30000 psi and a minimum tensile strength of 230-399 psi.
Springs commonly used in commercial products such as pens, office supplies, toys and other indoor supplies are made of hard wire (a kind of medium carbon steel). Because of the wide range of hardness, these springs can be particularly suitable for various applications, with Rockwell hardness ranging from C31 to C52.
Characteristics of compression spring material
Cold drawn and hard drawn are the cheapest spring steel, which are usually used for static load and low stress. This material is not suitable for temperatures below zero or above 2192 ° F (1200 ° C).
Cold drawn, quenched, tempered and multipurpose spring steel is called oil-tempered steel wire. However, it does not apply to accidental loads, fatigue or temperatures below zero or above 3272 ° F (1800 ° C). Alloy steel is very useful when we choose an environment under severe pressure.
Chromium-vanadium: It is an alloy spring steel that can withstand high temperature and stress up to 3992 ° F (2200 ° C). It has strong anti-fatigue performance and long-term impact and impact load bearing capacity.
Chromosilicon can be used to make springs that bear great pressure. It provides excellent performance at long life, shock loads and temperatures up to 4532 ° F (2500 ° C).
The piano wire is most commonly used for small springs. It can withstand repeated loads under high pressure and is the toughest material with the highest tensile strength. It cannot be used at temperatures below zero or above 2192 ° F (1200 ° C). Music line is usually the popular choice of spring.
The widely used alloy spring materials include stainless steel.
Brass and phosphor bronze springs have good conductivity and corrosion resistance. They are often used as contacts in electrical switches. Brass springs can be used at extremely cold temperatures.