DX51D Galvanized Steel | Definition, Properties, and Key Applications

Introduction

If you’re looking for a versatile and reliable steel solution, DX51D galvanized steel is a top choice. Known for its excellent corrosion resistance, formability, and suitability across multiple industries, this low-carbon, low-hardness steel has earned a solid reputation in construction, automotive, and appliance manufacturing.

What is DX51D Steel?

Definition: DX51D is a low-carbon, low-hardness steel grade under EN 10346, hot-dip galvanized to provide a durable zinc coating. Its design makes it ideal for cold-forming applications where corrosion resistance and flexibility are critical.

Designation Breakdown:

• D – Cold Forming Steel
• X – Rolling state (unspecified, can be hot-rolled or cold-rolled)
• 51 – Steel grade serial number (higher numbers indicate better formability)
• D – Hot-Dip Galvanized coating

   

Comparison with DX52D: DX52D offers higher ductility and elongation, making it suitable for more complex forming processes. DX51D is well-suited for standard forming applications.

Standards, Equivalent Grades, and Material Numbers

Material Numbers:

• 1.0917 (EN 10027-2) – Standard reference
• 1.0226 (EN 10346) – Common material number

   

Chemical Composition

Typical composition (%):

• C: 0.05–0.2
• Si: ≤0.5
• Mn: 0.3–1.2
• P: ≤0.05
• S: ≤0.05
• Ti: ≤0.3

   

Role of elements: Carbon for ductility, Mn for toughness, low P & S for weldability.

Mechanical Properties

• Yield Strength: 210–300 MPa
• Tensile Strength: 270–500 MPa
• Elongation: ≥22–40%
• Hardness: 80–120 HB
• Impact Strength: 30 J at -20°C (ASTM E23 standard)

   

Physical Properties & Heat Resistance

• Density: 7850 kg/m³
• Melting Point: 1425–1540°C
• Thermal Conductivity: 50 W/m·K
• Electrical Resistivity: 0.000017 Ω·m
• Max Service Temperature: Continuous 200°C, Intermittent 250°C
• Scaling Temperature: 300°C – risk of oxidation

   

Corrosion Resistance

DX51D’s zinc coating provides excellent atmospheric corrosion resistance, making it ideal for outdoor use.

• Limitations: Susceptible to acids, pitting in high-chloride environments
• Comparison with S235JR/S355: Superior outdoor corrosion performance

   

Coating Types and Thickness

Surface Treatment Options

• Chromate (+C, +S): Enhanced corrosion resistance
• Phosphate (+P, +Q, +T, +V): Paint-ready surfaces
• Oiling (+O): Temporary rust protection
• Untreated (+M): Custom processing

   

Surface Quality Grades

• A: Standard – Minor imperfections acceptable
• B: Improved – Smoother, suitable for painting
• C: High – Almost flawless, ideal for decorative applications

   

Fabrication Properties

• Formability: Excellent for cold/hot forming; recommended bend radii ~1.5× thickness
• Weldability: MIG, TIG, and spot welding supported; preheating for thick sections
• Machinability: Moderate; use sharp tools and proper cutting speeds
• Heat Treatment: Annealing (600–700°C) and Normalizing (850–900°C) improve ductility

   

Product Forms and Specifications

• Sheets: 0.3–3.0 mm thick, up to 1520 mm width
• Cold-Rolled Coils: 0.2–6.0 mm thick, 600–1500 mm width
• Hot-Rolled Coils: 3.0–12.0 mm thick, 600–2000 mm width
• Other: Pipes, tubes, roofing sheets, PPGI coils

   

Typical Applications

Maintenance and Handling

• Clean surfaces regularly to prevent corrosion
• Avoid scratches and impacts to maintain zinc layer integrity
• Prevent water stagnation to reduce pitting and rust formation

   

Selection Considerations and Supplier Guidance

When selecting DX51D, consider:

• Mechanical requirements
• Coating type
• Surface treatment
• Availability

   

ISO/TUV/SGS/CE-certified suppliers provide customization to match your project’s specifications, ensuring consistent quality and performance.

Conclusion:

DX51D galvanized steel combines corrosion resistance, formability, and versatility, making it a reliable choice for demanding industrial and consumer applications.

Delong Metal: Reliable DX51D Steel Supplier

At Delong Metal, we provide more than just DX51D steel—we deliver tailored solutions to meet your project needs. Our offerings include DX51D+Z, DX52D+Z, DX53D+Z, DX54D+Z, and DX56D+Z, all available with custom coatings, precise dimensions, and expert guidance to ensure every sheet and coil performs exactly as required.

Move beyond standard steel—share your specifications with us, and we’ll supply DX51D steel that fits perfectly in both size and performance.