Heat treatment hardening:
Working conditions and material and heat treatment requirements
1. Condition: spring with simple shape, small section and small force
Requirements: 65 785-815 ℃ oil quenching, 300 ℃, 400 ℃, 500 ℃. 600 ℃ tempering, corresponding hardness hb512, hb430, hb369, 75780-800 ℃ oil or water quenching, 400-420 ℃ tempering, hrc42-48
2. Condition: medium load large spring
Requirements: 60si2mna65mn 870 ℃ oil quenching, 460 ℃ tempering, hrc40-45 (65Mn quenched and tempered hb280-370 for agricultural machine seat spring)
3. Conditions: large plate spring and coil spring with heavy load, high spring and high fatigue limit
Requirements: 50CrVA, 60simna 860 ℃ oil quenching, 475 ℃ tempering, hrc40-45
4. Condition: coil spring with diameter of 8-10mm working under multiple alternating loads
Requirements: 50crmna840-870 ℃ oil quenching, 450-480 ℃ tempering, hb387-418
5. Conditions: locomotive, vehicle, coal water tanker or plate spring
Requirements: 55simn, 60Si2Mn hrc39-45 (hb363-432) (Jiefang plate spring: 55si2mn hb363-441)
6. Conditions: vehicle and buffer coil spring, automobile tension spring
Requirements: 55si2mn, 60Si2Mn, 60si2cra quenching and tempering, hrc40-47 or hb370-441
7. Conditions: plunger spring of diesel pump, fuel injection nozzle spring, air valve spring of agricultural diesel engine and valve spring and plate spring of medium and heavy vehicles
Requirements: 50CrVA quenching, tempering, hrc40-47
8. Conditions: coil spring and flat spring working under high temperature steam, water pipe spring and seawater corrosion resistant spring, Φ 10-25mm
Requirements: 3cr13hrc39-46 4Cr13 hrc48-50 hrc48-49 hrc47-49 hrc37-40 hrc31-35 hrc33-47
9. Condition: spring working in acid-base medium
Requirements: 2cr18ni91100-1150 ℃ water quenching, stress relief after winding, tempering at 400 ℃ for 60min, hb160-200
10. Condition: circlip δ 4, Φ eighty-five
Requirements: 60Si2 400 ℃ preheating, 860 ℃ oil quenching, 430 ℃ tempering air cooling, hrc40-45
