This article references the “Encyclopedia of Metal Materials” and the national standard GB/T 699-2015 to provide a detailed analysis of the performance characteristics and processing applications of 15F rimmed steel. 15F is a commonly used low-carbon rimmed steel with slightly higher strength than 08F/10F, while maintaining good cold formability and weldability.
1. Basic Information of 15F
15F is a high-quality carbon structural steel, implemented under the GB/T 699-2015 standard. “15” indicates an average carbon content of approximately 0.15%, and “F” denotes rimmed steel (Rimmed Steel). This steel grade has a moderately low carbon content, very low silicon content (≤0.07%), exhibits good cold stamping formability and a certain level of strength, making it suitable for stamping parts and structural components requiring some load-bearing capacity. Being a rimmed steel, it has internal segregation; attention to sampling location is necessary for critical load-bearing components.
2. Chemical Composition
| Element | Content (%) |
|---|---|
| Carbon (C) | 0.12-0.18 |
| Silicon (Si) | ≤0.07 |
| Manganese (Mn) | 0.25-0.50 |
| Phosphorus (P) | ≤0.035 |
| Sulfur (S) | ≤0.035 |
| Chromium (Cr) | ≤0.25 |
| Nickel (Ni) | ≤0.30 |
| Copper (Cu) | ≤0.25 |
3. Mechanical Properties
| Property | Value | Condition |
|---|---|---|
| Tensile Strength | ≥375 MPa | Normalized condition |
| Yield Strength | ≥225 MPa | Normalized condition |
| Elongation | ≥27% | Normalized condition |
| Reduction of Area | ≥55% | Normalized condition |
| Hardness | ≤143 HB | Hot-rolled or annealed condition |
4. Heat Treatment Characteristics
The heat treatment characteristics of 15F are as follows:
- Normalizing: 900-940°C, air cooling, refines grain structure
- Annealing: 680-740°C, furnace cooling or air cooling, stress relief
- Carburizing: Surface carburizing treatment possible (900-930°C), quenching after carburizing provides a hardened surface layer
- Quenching and Tempering: Can be performed under certain conditions (quenching 860-900°C + tempering 500-650°C), but hardness increase is limited
- Weldability: Good, suitable for gas welding and arc welding
5. Typical Applications
- Automotive parts (stamped structural components, brackets, chassis reinforcement plates)
- Machinery manufacturing (flanges, connectors, tube sheets)
- Vessel manufacturing (pressure vessel heads, shells)
- Building hardware (connecting plates, fastening brackets)
- Agricultural machinery parts (frames, guards, shields)
- CNC machined parts (precision hole machining of stamped blanks, contour milling)
6. CNC Machining Performance
CNC machining characteristics of 15F:
- Cutting Performance: Low-carbon steel, tendency to stick to the tool is slightly lower than 08F/10F, but attention should still be paid to built-up edge control.
- Cutting Speed: 150-250 m/min (coated carbide tools)
- Tool Selection: Carbide + PVD coated tools, rake angle 10-15°
- Cooling: Emulsion cutting fluid concentration 5-8%, adequate supply
- Accuracy: CNC finishing after stamping can achieve IT7-IT8 tolerance grades
7. Purchasing Guide
Market Price Reference (2025 market conditions):
- Cold-rolled sheet (0.5-3mm): 5-8 RMB/kg
- Hot-rolled plate (3-12mm): 4-6.5 RMB/kg
- Round bar: 4.5-6.5 RMB/kg
- Strip steel: 5-7.5 RMB/kg
8. Data Sources
- GB/T 699-2015 “High-quality Carbon Structural Steels”
- “Encyclopedia of Metal Materials” 15F Special Entry
9. Our Services
Dongguan Stirling Metal Products Co., Ltd. specializes in providing a One-Stop Service for 15F material + CNC machining:
- ✅ Material Procurement: Genuine products guaranteed, with complete material certificates
- ✅ CNC Machining: Accuracy ±0.01mm, smooth surface finish
- ✅ Sample Production: Fast delivery in 3-5 days
- ✅ Batch Production: Delivery time of 7-15 days
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