DX55D Steel Grades
High-Strength Hot-Dip Galvanized Steel for Deep-Drawing and Structural Applications
- Technical Support
DX53D Steel Technical Specifications & Applications
DX55D is a high-strength, hot-dip galvanized steel grade compliant with EN 10346, featuring a minimum yield strength of 550 MPa. It offers an optimal balance of strength, formability, and corrosion resistance, making it suitable for various applications in construction and manufacturing.
This steel grade is widely used in structural framing, purlins, and heavy-duty roll-formed sections. Its excellent weldability and cold-forming properties allow for efficient processing in bending, cutting, stamping, and roll-forming operations. Manufactured under stringent quality controls, DX55D meets international standards, ensuring reliable performance in galvanized and structural steel applications. As a core product of Hengze Steel Group, DX55D is trusted globally for durable, high-performance galvanized structural steel solutions in construction, engineering, and manufacturing sectors.
Table of Contents
1. Typical Uses & Selection Guidance
- Structural Applications
DX55D is a high-strength, hot-dip galvanized steel grade produced to EN 10346 standards, engineered for demanding cold-forming applications. With a minimum yield strength of 550 MPa, it delivers an excellent combination of strength, formability, and corrosion resistance. DX55D is widely used in structural framing, purlins, and heavy-duty roll-formed sections. Its superior weldability and cold-forming properties support efficient bending, cutting, stamping, and roll-forming operations. Manufactured under strict quality control, DX55D ensures consistent performance for structural and industrial applications.
- Corrosion Protection
DX55D is coated with aluminium-silicon (AS) for enhanced corrosion and high-temperature resistance. This durable coating provides long-term protection against rust and oxidation, even in harsh industrial or outdoor environments, while maintaining a smooth surface finish suitable for painting or further processing.
- Forming Advantages
DX55D offers excellent formability with elongation ≥30% and minimal springback, ideal for producing complex shapes with high dimensional accuracy. Stringent production standards guarantee uniform mechanical properties, compliance with international specifications, and reliable performance in structural and engineering applications.
2. Technical Specifications Table
1. Chemical Composition Requirements (Maximum %)
| Steel Grade | Carbon (C) | Silicon (Si) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Titanium (Ti) |
|---|---|---|---|---|---|---|
| DX55D | ≤ 0.12% | ≤ 0.50% | ≤ 0.60% | ≤ 0.10% | ≤ 0.045% | ≤ 0.30% |
2. Mechanical Property Requirements (Maximum Values)
| Steel Grade | Min. Yield Strength (MPa) | Min. Tensile Strength (MPa) | Min. Elongation (%) Lo=80 mm | Bend Angle (°) | Mandrel Diameter (× Thickness t) |
|---|---|---|---|---|---|
| DX55D | 140–240 | 270–370 | ≥30% | 180° | 6t |
3. Coating Adhesion (180° Bend Test) Requirements
| Coating Class | Mandrel Diameter (× Thickness t) |
|---|---|
| Z100, Z200 | 1t |
| Z275, Z350, Z450, AZ150, AZ200, AM100, AM125, AM150, AM175, AM200, AM225 | 2t |
| Z600 | 3t |
4. Applicable Hot-Dip Metallic Coating Types
| Coating Class | Composition (%) | Key Features |
|---|---|---|
| Z (Zinc) | ≥99% Zinc | Basic corrosion protection; suitable for general use. |
| ZA (Zinc-Aluminium) | 95% Zn, 5% Al | Improved corrosion resistance over pure zinc. |
| ZF (Zinc-Iron) | Zinc with iron alloy | Enhanced hardness and wear resistance. |
| ZM (Zinc-Magnesium) | Zn with 2–4% Mg, 5–13% Al | Superior corrosion resistance in harsh environments. |
| AZ (Aluminium-Zinc) | 55% Al, 43.5% Zn, 1.5% Si | Excellent corrosion resistance and heat reflectivity. |
| AM (Aluminium-Magnesium) | Al with Mg alloy | High corrosion resistance; suitable for high-temperature applications. |
3. DX55D vs G550 — What’s the Difference?
| Property | DX55D Steel Grade | G550 Steel Grade |
|---|---|---|
| Yield Strength | 140–240 MPa | 550 MPa |
| Tensile Strength | 270–370 MPa | 550 MPa |
| Elongation (80 mm) | ≥ 30% | 2% |
| Bendability | 180° with 6t mandrel | 180° with 4t mandrel |
DX55D Steel FAQ：
DX55D is a low-carbon, hot-dip galvanized steel grade produced to EN 10346 standards. It is designed for deep-drawing and complex cold-forming applications, combining high formability with excellent corrosion resistance. Typical uses include automotive body panels, household appliances, and precision-engineered components.
DX55D provides a balance of strength and formability:
Yield Strength: 140–240 MPa
Tensile Strength: 270–370 MPa
Elongation (Lo=80 mm): ≥30%
These properties allow efficient bending, cutting, stamping, and roll-forming operations while maintaining structural integrity.
The "AS" coating is an aluminum-silicon layer that enhances heat and corrosion resistance. DX55D+AS can withstand temperatures up to 800°C, making it suitable for high-temperature applications such as automotive exhaust systems.
DX55D is widely used in:
Automotive body panels and structural components
Household appliance housings
Architectural and construction profiles requiring precise cold-forming
Precision-engineered parts with complex shapes
Its combination of corrosion resistance and high formability makes it ideal for demanding industrial applications.
Compared to other DX series grades, DX55D offers superior formability due to lower yield and tensile strengths, making it suitable for deep-drawing and complex shapes. Higher-strength grades like DX56D or DX57D provide greater strength but lower formability, so selection depends on the application requirements.
