1.4016 (known as SUS430 in Japanese Industrial Standards, JIS) is a widely used ferritic stainless steel belonging to the 430-series. It is valued for its balance of corrosion resistance, mechanical stability, and cost-effectiveness, making it a popular choice in applications where high nickel content (found in austenitic grades like 304) is unnecessary.
Chemical Composition
The core alloying elements of 1.4016 (SUS430) are defined by standards such as EN 10088 and JIS G4305:
Element Content Range (%) Role
Carbon (C) ≤ 0.12 Enhances strength but is kept low to avoid carbide precipitation, which reduces corrosion resistance.
Chromium (Cr) 16.00 – 18.00 Primary corrosion-resistant element; forms a passive chromium oxide layer on the surface.
Manganese (Mn) ≤ 1.00 Improves hot workability and strengthens the alloy.
Silicon (Si) ≤ 1.00 Enhances oxidation resistance and acts as a deoxidizer during production.
Phosphorus (P) ≤ 0.040 Limited to prevent brittleness, especially in welded joints.
Sulfur (S) ≤ 0.030 Lower than in 430F (1.4104) to prioritize corrosion resistance over machinability.
Key Properties
1. Mechanical Properties
Tensile Strength: 450 – 600 MPa
Yield Strength: ≥ 205 MPa
Elongation: ≥ 20% (in 50 mm, annealed condition)
Hardness: ≤ 183 HB (annealed); can increase to ~250 HB with cold working.
2. Corrosion Resistance
Moderate atmospheric resistance: Performs well in dry or mildly humid air, resisting rust in most urban and rural environments.
Resistance to fresh water and mild chemicals: Suitable for contact with tap water, dilute organic acids, and non-chloride cleaners.
Limitations: Inferior to austenitic stainless steels (e.g., 304, 316) in harsh environments. Susceptible to pitting/crevice corrosion in saltwater, high chloride solutions, or strong acids.
3. Machinability
Fair to good: Less machinable than 430F (1.4104) due to lower sulfur content. Rated ~60% compared to 1215 free-cutting steel.
Requires proper tooling and cutting fluids to avoid work hardening.
4. Heat Treatment
Annealing: 700 – 800°C, followed by slow cooling, to soften the material, restore ductility, and optimize corrosion resistance.
Non-hardenable by quenching: Unlike martensitic stainless steels (e.g., 410), ferritic grades do not respond to heat treatment for hardening.
5. Weldability
Weldable using common methods (TIG, MIG), but may form brittle phases in the heat-affected zone (HAZ) if not post-weld annealed.
Low carbon content minimizes carbide precipitation during welding, reducing the risk of intergranular corrosion.
Applications
1.4016 (SUS430) is widely used in applications requiring moderate corrosion resistance and cost efficiency:
Household Appliances: Inner liners of ovens, refrigerators, dishwashers, and washing machine drums (resists food acids and moisture).
Architectural Components: Decorative trim, railings, and cladding in dry/mildly humid climates.
Automotive Parts: Exhaust manifolds (after heat treatment for oxidation resistance), trim, and underbody components.
Cookware: Budget-friendly stainless steel pans and utensils (non-magnetic, unlike 304).
Industrial Equipment: Pipes, tanks, and valves for handling fresh water or non-aggressive fluids.
Comparison with Related Alloys
Alloy Corrosion Resistance Machinability Cost Magnetic? Key Use Case
1.4016 (430) Moderate Fair Low Yes Appliances, architectural trim
1.4104 (430F) Moderate (slightly lower) Excellent Low-Medium Yes Machined parts, fasteners
1.4301 (304) High Fair Medium No Food processing, marine use
1.4003 (410) Low-Moderate Fair Low Yes Hardened components (e.g., knives)
Limitations
Poor performance in chloride-rich environments (e.g., coastal areas, de-iced roads).
Lower toughness at sub-zero temperatures compared to austenitic grades.
Susceptible to grain growth and embrittlement if overheated during welding.
In summary, 1.4016 (SUS430) is a versatile, cost-effective ferritic stainless steel ideal for non-critical applications requiring moderate corrosion resistance, magnetic properties, and ease of fabrication. Its balance of performance and affordability makes it a staple in household, automotive, and architectural industries.