High-Carbon Spring Tempering Steel Wire: Technical Specifications & Industrial Applications
Material Overview
High-carbon spring tempering steel wire (C: 0.45–1.00%) is engineered for coil spring manufacturing, prioritizing fatigue resistance, elastic modulus, and cyclic load durability over fixed chemical compositions. Performance metrics include tensile strength (1,500–3,000 MPa), torsion cycles (>50,000), and bend compliance (ASTM E290).
Classification & Technical Standards
1. Hard-Drawn Spring Wire (HDMB)
- Carbon Content: 0.45–0.85%
- Processing: Cold-drawn without post-treatment
- Key Properties:
- Tensile Strength: 1,600–2,200 MPa
- Surface Hardness: 400–500 HV
- Fatigue Limit: 45–55% of UTS
- Standards:
Specification Finish Diameter Range ASTM A227 Uncoated 0.5–16 mm ASTM A764 Galvanized (Zn) 1.0–12 mm
2. Oil-Tempered Spring Wire (OTMB)
- Carbon Content: 0.55–0.85%
- Processing: Quenching (850–900°C) + oil tempering (400–500°C)
- Key Properties:
- Tensile Strength: 1,800–2,500 MPa
- Toughness: 100–150 J (Charpy V-notch)
- Decarburization Depth: ≤1.5% of diameter
- Standards:
Specification Surface Quality Application Scope ASTM A229 Bare/Polished Automotive valves, clutches
3. Music Spring Wire (ASTM A228)
- Carbon Content: 0.70–1.00%
- Processing: Patenting (900°C铅浴淬火) + stress-relief annealing
- Key Properties:
- Tensile Strength: 2,600–3,000 MPa
- Diameter Tolerance: ±0.005 mm (≤0.25″)
- Surface Roughness: Ra ≤0.4 μm
- Surface Treatments:
Type Thickness Corrosion Resistance Phosphate 2–5 μm Moderate (500h salt spray) Bright Finish N/A Industrial cleanliness Tin-Plated 3–8 μm High (1,000h salt spray)
Critical Performance Metrics
| Property | HDMB | OTMB | Music Wire |
|---|---|---|---|
| Elastic Modulus (GPa) | 190–210 | 200–215 | 210–230 |
| Torsional Stress (MPa) | 800–1,200 | 1,000–1,500 | 1,300–1,800 |
| Relaxation (%) | ≤3.5 | ≤2.0 | ≤1.5 |
| Maximum Service Temp | 120°C | 180°C | 150°C |
Industrial Applications
1. Automotive Systems
- Suspension Springs: OTMB (Ø8–20 mm, ASTM A229)
- Valve Springs: Music wire (Ø1.6–4.0 mm, HV 550–650)
2. Precision Engineering
| Component | Wire Type | Specification |
|---|---|---|
| Medical Devices | Music Wire | ASTM A228, Ø0.1–0.5 mm |
| Watch Hairsprings | Music Wire | HV 600–700, Ra ≤0.2 μm |
3. Heavy Machinery
- Industrial Valve Springs: HDMB (Galvanized, ASTM A764)
- Hydraulic Seals: OTMB (Polished, ≤0.05mm ovality)
Quality Assurance
- Metallurgical Testing:
- Inclusion rating ≤B2 (ASTM E45)
- Decarburization ≤0.5% depth (EN ISO 3887)
- Certifications:
- ISO 9001:2015 (Batch traceability)
- IATF 16949 (Automotive compliance)
Storage Guidelines:
- Temperature: 10–35°C
- Humidity: <60% RH
- Shelf Life: 12 months (VCI packaging)
Custom Services: Precision coiling (±0.1° pitch accuracy), cryogenic treatment (-80°C × 8h for stress homogenization).
Packing And Delivery
