DIN 1.4006 Stainless Steel: Ferritic Grade for Decorative & Mildly Corrosive Applications
DIN 1.4006 (AISI 430) is a ferritic stainless steel grade characterized by its 16-18% chromium content and low carbon composition, offering moderate corrosion resistance, excellent formability, and cost-effectiveness. Unlike austenitic grades, it is non-hardenable by heat treatment and magnetic in all conditions. This grade is widely specified for architectural trim, automotive components, and consumer appliances where aesthetic appeal and mild corrosion resistance are prioritized over extreme durability. Below is a technical breakdown of its metallurgical properties, processing methods, and application guidelines.
1. Chemical Composition (DIN EN 10088-2 Standard)
| Element | Content Range | Function |
|---|---|---|
| Carbon (C) | ≤ 0.08% | Minimized to prevent intergranular corrosion and maintain ductility |
| Chromium (Cr) | 16.00 – 18.00% | Primary alloying element for passive film formation and corrosion resistance |
| Manganese (Mn) | ≤ 1.00% | Enhances hot workability; residual from steelmaking process |
| Silicon (Si) | ≤ 1.00% | Improves oxidation resistance and deoxidation during melting |
| Phosphorus (P) | ≤ 0.040% | Impurity; controlled to maintain mechanical properties |
| Sulfur (S) | ≤ 0.015% | Minimized to improve machinability and surface quality |
| Nitrogen (N) | ≤ 0.030% | Residual element; excessive amounts reduce ductility |
2. Mechanical Properties (Annealed Condition)
- Tensile Strength (Rm): 450-600 MPa (varies with thickness and cold working)
- Yield Strength (Rp0.2): ≥ 270 MPa (minimum guaranteed for structural integrity)
- Elongation (A5): ≥ 22% (adequate for deep drawing and forming operations)
- Hardness (HB): ≤ 183 (Brinell); ≤ 90 HRB (Rockwell) in annealed state
- Modulus of Elasticity: 220 GPa (typical for ferritic stainless steels)
- Thermal Conductivity: ~26 W/m·K at 100°C (superior to austenitic grades for heat dissipation)
3. Manufacturing & Processing Characteristics
- Melting Practice: Electric arc furnace (EAF) followed by argon oxygen decarburization (AOD) to achieve low carbon and nitrogen levels, ensuring ferritic microstructure stability.
- Hot Rolling: Conducted at 900-1100°C to avoid grain coarsening; air cooling suffices due to absence of phase transformation.
- Cold Rolling: Performed for thin gauges (≤ 3mm) with intermediate annealing at 750-850°C to relieve work hardening and restore ductility.
- Annealing: Full annealing at 780-850°C followed by air cooling to optimize softness and corrosion resistance; avoids embrittlement risks associated with 475°C temper embrittlement.
- Surface Finishing: Common finishes include 2B (cold-rolled, bright annealed), BA (bright annealed for reflective surfaces), and No.4 (brushed for architectural applications).
4. Key Application Sectors
Architectural & Interior Design
Decorative trim, elevator panels, handrails, and wall cladding — preferred for its aesthetic versatility and cost efficiency compared to 304/316 grades. Resists atmospheric corrosion in indoor environments.
Automotive Components
Exhaust system trim, fuel filler caps, and interior decorative parts. Used where moderate heat resistance (up to 400°C) and formability are required without the need for high corrosion resistance.
Consumer Appliances
Refrigerator liners, washing machine drums, microwave oven cavities, and kitchen sinks. Selected for its combination of hygiene, cleanability, and economic viability.
Industrial Equipment
Non-structural components in chemical processing (non-chloride environments), heat exchanger fins, and nitric acid storage tanks (≤ 10% concentration). Avoid use in reducing acid or chloride-rich media.
5. Comparison with Competing Grades
| Grade | Type | Key Advantages | Limitations |
|---|---|---|---|
| DIN 1.4006 (430) | Ferritic | Cost-effective; good formability; thermal conductivity | Limited corrosion resistance; poor low-temperature toughness |
| DIN 1.4301 (304) | Austenitic | Superior corrosion resistance; non-magnetic; cryogenic toughness | Higher cost; lower thermal conductivity |
| DIN 1.4016 (430Ti) | Ferritic (Ti-stabilized) | Improved high-temperature scaling resistance | Higher alloy cost; limited availability |
| DIN 1.4509 (441) | Ferritic (Nb-stabilized) | Enhanced corrosion/weldability; automotive exhaust systems | Reduced formability vs. 1.4006 |
6. Design & Fabrication Considerations
- Corrosion Limitations: Avoid prolonged exposure to chloride ions (e.g., coastal areas, de-icing salts) or acidic solutions (pH < 4). Pitting resistance equivalent (PREN) of ~17 limits use in aggressive environments.
- Welding Guidelines: Use filler metals like ER430 or ER309L for dissimilar joints; preheat to 150-200°C for thick sections (>6mm) to prevent cracking. Post-weld annealing recommended for critical applications.
- Forming Recommendations: Suitable for deep drawing with generous radii (minimum bend radius = 1.0×thickness for 90° bends). Avoid sharp notches to prevent stress concentration.
- Surface Protection: Apply protective films during transportation/storage to prevent surface contamination. Passivation with nitric acid (20-30%) can enhance corrosion resistance post-fabrication.
- Temperature Constraints: Not recommended for service above 400°C (oxidation risk) or below -20°C (ductile-to-brittle transition). Avoid thermal cycling to prevent embrittlement.
7. Request a Custom Quote for DIN 1.4006 Stainless Steel
For precision-cut DIN 1.4006 stainless steel sheets, coils, or custom-fabricated components, contact Baoli Iron & Steel’s technical team. We provide mill-certified material with traceable heat numbers, tailored surface finishes, and just-in-time delivery for global industrial projects.