Compression Spring Application
The compressed spring steel spring is used for all types of motor, motor, etc., as it is the type of spring required. The load is acted on them or their ends are compressed. The design of the compression spring is compressed, and the design attempts to return the spring to the original shape, so that the load is pushed back.
Main applications: medical breathing equipment, medical mobile equipment, manual tools, home care equipment, shock absorption, engine valve spring.
Strengthening process
Compressed spring is a hardware accessory with a spiral geometric shape formed by wire, so its hardening and strengthening operation is more difficult than flat hardware accessories (such as stamping parts). In addition, it is necessary to strictly control the hardening effect of the transverse section of the pressure spring, so as to fully understand the resistance of the pressure spring to fatigue fracture after use.
Compressed spring hardening generally adopts two methods: shot peening hardening and heat treatment hardening.
Shot peening and hard spring pressing treatment: To handle a batch of pressure springs, they can be individually transported to the shot blasting chamber by conveyor belts. There is a set of parallel rod tracks installed in the shot blasting chamber, which strengthen and roll to the rolling position, driving the edge of the pressure spring to rotate forward. This rotation allows high-speed shot flow to pass through the middle of each coil of the pressure spring and hit the metal surface of the inner ring, which is precisely the area where the stress of the pressure spring is most concentrated, Shot peening is the best strengthening method for suspension springs, and the fatigue life of high stress springs can be increased by more than four times after appropriate shot peening.
Heat treatment hardening:
1.Working conditions and material and heat treatment requirements
1. 1 Condition: Spring with simple shape, small cross-section, and low stress
Requirements: 65 785-815 ℃ oil quenching, 300 ℃ 400 ℃, 500 ℃. Tempered at 600 ℃, corresponding hardness HB512, HB430, HB369, 75780-800 ℃ oil or water quenching, tempered at 400-420 ℃, HRC42-48
1.2. Condition: Medium load large spring
Requirements: 60Si2MnA65Mn 870 ℃ oil quenching, 460 ℃ tempering, HRC40-45 (agricultural machinery seat spring 65Mn quenching and tempering HB280-370)
1.3. Conditions: Large shaped leaf springs and spiral springs with heavy loads, high springs, and high fatigue limits
Requirements: 50CrVA, 60SiMnA 860 ℃ oil quenching, 475 ℃ tempering, HRC40-45
1.4. Condition: A coil spring with a diameter of 8-10mm that operates under multiple alternating loads
Requirements: 50CrMnA840-870 ℃ oil quenching, 450-480 ℃ tempering, HB387-418
1.5. Conditions: Locomotive, vehicle, coal water vehicle or plate spring
Requirement: 55SiMn, 60Si2Mn HRC39-45 (hb363-432) (Jiefang Automobile Leaf Spring: 55Si2Mn HB363-441)
1.6. Conditions: Vehicle and buffer coil springs, vehicle tension springs
Requirements: 55Si2Mn, 60Si2Mn, 60Si2CrA quenched, tempered, HRC40-47 or HB370-441
1.7. Conditions: Diesel pump plunger spring, fuel injector spring, agricultural diesel engine valve spring, and valve spring and plate spring for medium and heavy vehicles
Requirement: 50CrVA quenching, tempering, HRC40-47
1.8. Conditions: Coil springs and flat springs working under high temperature steam, springs for water pipes, and springs resistant to seawater erosion, Φ 10-25mm
Requirement: 3Cr13HRC39-46 4Cr13 HRC48-50 HRC48-49 HRC47-49 HRC37-40 HRC31-35 HRC33-47
1.9. Conditions: Springs operating in acidic and alkaline media
Requirement: 2Cr18Ni91100-1150 ℃ water quenching, stress relief after winding, tempering at 400 ℃ for 60 minutes, HB160-200
1.10. Condition: Elastic retaining ring δ 4, Φ eighty-five
Requirements: 60Si2 preheating at 400 ℃, 860 ℃ oil quenching, 430 ℃ tempering and air cooling, HRC40-45
2、 Remarks
2.1. Spring heat treatment generally requires quenching, fine grain size, and less residual austenite. The depth of decarburization layer on each side should comply with:< Φ 6mm steel wire or steel plate should Φ 6mm steel wire plate should have a diameter or thickness of<1.0%
2.2. Large springs are immediately quenched and tempered after hot processing, while medium-sized springs are formed after cold processing (raw materials require spheroidized structure or most of the spheroidized structure), and then quenched and tempered. Small springs are formed after cold processing with cold rolled steel strips, cold drawn steel wires, etc., and then tempered at low temperature
2.3. After treatment, it can be shot peened:
Compressed air of 40-50N/cm2 or a centrifuge with a linear speed of 70m/s will Φ 0.3-0.5mm (for small parts, valve springs, gears, etc.) Φ 0.6-0.8mm (for plate springs, crankshafts, half shafts, etc.) cast iron shot or quenched steel shot is sprayed onto the surface of the spring to strengthen the surface layer. The number of fatigue cycles can be increased by 8-13 times, and the service life can be increased by more than 2-2.5 times.