SPCC: Standard Cold-Rolled Low-Carbon Steel Sheet
SPCC, as defined by the Japanese Industrial Standard (JIS G 3141), represents a standard grade of cold-rolled low-carbon steel sheet (UNS designation not applicable; equivalent to ASTM A1008 CS Type B). With a maximum carbon content of 0.15%, SPCC offers excellent formability, surface quality, and cost-effectiveness, making it ideal for deep drawing, stamping, and general fabrication. This article explores its chemical makeup, mechanical attributes, production methods, applications, and comparative analysis with related grades.
1. Core Chemical Composition (JIS G 3141 Standard)
| Element | Content Range | Function |
|---|---|---|
| Carbon (C) | ≤ 0.15% | Provides basic strength; low levels ensure good ductility and formability |
| Manganese (Mn) | ≤ 0.60% | Improves hardenability and deoxidizes the steel during melting |
| Phosphorus (P) | ≤ 0.100% | Controlled impurity; limits brittleness and enhances weldability |
| Sulfur (S) | ≤ 0.035% | Restricted to prevent hot shortness and improve machinability |
| Others | Fe balance; trace elements like Si ≤ 0.05% typical | Maintains overall purity for consistent performance |
2. Key Mechanical Properties (Room Temperature)
- Tensile Strength: ≥ 270 MPa (varies with thickness; ensures adequate load capacity)
- Yield Strength: ≥ 140-215 MPa (depending on sheet thickness; supports forming without excessive springback)
- Elongation: ≥ 36-48% (high ductility for deep drawing and bending operations)
- Hardness (HRB): 50-85 (Rockwell B; soft enough for easy processing and finishing)
- Bending Performance: Good 180° bend radius; no cracking in standard tests for thicknesses up to 2.0 mm
3. Manufacturing Process Characteristics
- Hot Rolling: Base material from low-carbon slab melted in basic oxygen furnace (BOF) or electric arc furnace (EAF), hot-rolled at 900-1100°C to produce hot-rolled coil (HRCO).
- Pickling: Acid pickling (HCl or H2SO4) to remove mill scale, followed by rinsing to prepare surface for cold reduction.
- Cold Rolling: Multi-pass reduction (20-50% per pass) at ambient temperature to achieve final thickness (0.3-3.5 mm), with lubrication to control friction and surface quality.
- Annealing: Continuous annealing at 650-750°C in a controlled atmosphere (H2-N2 mix) to recrystallize the microstructure, relieve stresses, and improve formability.
- Skin Pass & Finishing: Light temper rolling (0.5-2% elongation) for shape correction and surface texture (e.g., matte or bright finish); optional temper rolling for enhanced flatness.
4. Typical Application Fields
Automotive Industry
Body panels, fenders, interior trim, and structural components — leverages deep drawability for complex shapes.
Home Appliances & Furniture
Refrigerator shells, washing machine parts, cabinet panels, and office furniture — provides smooth surface for painting and plating.
Electronics & Packaging
Computer chassis, metal cans, drums, and enclosures — cost-effective for high-volume production with good weldability.
General Fabrication
Stampings, brackets, shelving, and HVAC ducts — versatile for bending, punching, and assembly in light engineering.
5. Difference from Similar Grades (SPCC vs SPCD vs SPCE)
| Grade | Carbon Content | Key Advantage | Suitable Scenario |
|---|---|---|---|
| SPCC | ≤ 0.15% | Balanced formability and strength; economical | General stamping and drawing (non-critical deep draws) |
| SPCD | ≤ 0.12% | Improved ductility for deeper forming | Automotive outer panels and appliance housings |
| SPCE | ≤ 0.10% | Superior elongation and low yield for complex shapes | Deep-drawn parts like fuel tanks and structural tubing |
6. Selection & Usage Precautions
- Corrosion Considerations: Not inherently corrosion-resistant; apply zinc coating (galvanizing) or painting for outdoor/humid exposure to prevent rust.
- Forming Limits: Avoid over 50% reduction in single pass during deep drawing; use lubricants to minimize galling and tool wear.
- Welding Recommendations: Suitable for resistance spot/MIG welding; use ER70S-6 filler for arc welding to maintain joint integrity.
- Quality Assurance: Verify compliance with JIS G 3141 via mill certificates; inspect for surface defects (e.g., coil breaks, stretcher strains) per ISO 9001 standards.
7. Get a Steel Quote
If you need customized SPCC cold-rolled steel sheets, coils, or blanks, or require a competitive price quote, contact our team. We offer professional guidance and wholesale pricing tailored to your specifications.