DIN 17102 StE255 Hot Rolled Steel Coil
DIN 17102 StE255 Hot Rolled Steel Coil - Normalized Fine-Grain Structural Steel Data & Equivalents
Detailed material analysis of StE255 hot rolled steel coil under DIN 17102, featuring chemical composition, mechanical properties, physical constants, full international equivalents, and application guidance.
Cutting, cold forming, hot forming, welding (all common arc and resistance methods), machining, drilling
- Phone : +8618037372205
- Email : [email protected]
- WhatsApp: Contact via Whtsapp
- WeChat: +8618037372205
DIN 17102 StE255 Hot Rolled Steel Coil Introduction
StE255 is a normalized fine-grain structural steel defined by the historical German standard DIN 17102. It is supplied as hot rolled coil, plates, or sections and is intended for welded steel constructions where guaranteed yield strength and good weldability are required. The 'StE' designation indicates a killed fine-grain steel ('St' for steel, 'E' for fine-grain treated with aluminium). The number 255 specifies the minimum yield strength of 255 MPa for thicknesses up to 16 mm.
The steel is delivered in the normalized condition (+N) which imparts a uniform fine-grain microstructure, providing a balanced combination of strength and toughness at ambient and low temperatures. Typical applications include bridges, building frames, crane constructions, and heavy machinery components.
- Minimum yield strength 255 MPa (t ≤ 16 mm)
- Tensile strength between 360 and 480 MPa
- Good cold forming and welding characteristics
- Suitable for static and dynamic loads
DIN 17102 StE255 Hot Rolled Steel Coil Chemical Composition
The typical ladle analysis for StE255 according to DIN 17102. The steel is fully killed and fine-grain treated with aluminium. Microalloying elements such as niobium, vanadium, or titanium may be present in small amounts for grain refinement and to meet mechanical requirements, but are not mandatory. Maximum limits for phosphorus and sulphur ensure good weldability and toughness.
| Chemical Element | Standard Value (max unless range) | Remarks |
|---|---|---|
| Carbon (C) | 0.20 | Max, ladle analysis |
| Silicon (Si) | 0.50 | Max |
| Manganese (Mn) | 0.50 – 1.40 | Range |
| Phosphorus (P) | 0.035 | Max |
| Sulfur (S) | 0.030 | Max |
| Nitrogen (N) | 0.012 | Max (sample) |
| Aluminium (Altot or Alsol) | ≥ 0.020 | Min, acid soluble aluminium for grain refinement |
| Niobium (Nb)* | ≤ 0.05 | Optional microalloy; if added |
| Vanadium (V)* | ≤ 0.10 | Optional microalloy; if added |
| Titanium (Ti)* | ≤ 0.05 | Optional microalloy; if added |
DIN 17102 StE255 Hot Rolled Steel Coil Physical Properties
Physical constants for StE255 fine-grain structural steel at room temperature unless otherwise noted. These values serve as engineering design data and are valid for the normalized condition. Actual properties may vary slightly with exact composition and heat treatment history.
| Property | Typical Value | Unit | Condition / Temperature |
|---|---|---|---|
| Density (ρ) | 7.85 | g/cm³ | Room temperature |
| Elastic modulus (E) | 210 | GPa | 20 °C |
| Shear modulus (G) | 81 | GPa | 20 °C |
| Poisson's ratio (ν) | 0.30 | – | 20 °C |
| Thermal expansion coefficient (α) | 11.5·10⁻⁶ | K⁻¹ | 20 – 100 °C |
| Thermal expansion coefficient (α) | 12.0·10⁻⁶ | K⁻¹ | 20 – 200 °C |
| Thermal expansion coefficient (α) | 12.5·10⁻⁶ | K⁻¹ | 20 – 300 °C |
| Thermal conductivity (λ) | 50 | W/(m·K) | 20 °C |
| Specific heat capacity (cp) | 460 | J/(kg·K) | 20 °C |
| Electrical resistivity (ρe) | 0.25 | µΩ·m | 20 °C |
DIN 17102 StE255 Hot Rolled Steel Coil Mechanical Properties
Mechanical test values for StE255 as delivered in the normalized condition. The longitudinal test specimens are taken from hot rolled coil or plate. Yield strength decreases with increasing product thickness. The elongation values correspond to gauge length L0 = 5.65√S0 (A5). No mandatory impact test is specified for the base grade, but supplementary toughness verification to J0 or J2 quality can be agreed at the time of order.
| Property | Standard Value | Unit | Test Condition / Remarks |
|---|---|---|---|
| Yield strength (ReH) | ≥ 255 | MPa | Thickness ≤ 16 mm |
| Yield strength (ReH) | ≥ 235 | MPa | Thickness 16 < t ≤ 40 mm |
| Yield strength (ReH) | ≥ 225 | MPa | Thickness 40 < t ≤ 60 mm |
| Yield strength (ReH) | ≥ 215 | MPa | Thickness 60 < t ≤ 80 mm |
| Tensile strength (Rm) | 360 – 480 | MPa | All thicknesses |
| Elongation (A5) | ≥ 24 | % | Longitudinal, t ≤ 16 mm |
| Elongation (A5) | ≥ 23 | % | Longitudinal, 16 < t ≤ 40 mm |
| Elongation (A5) | ≥ 22 | % | Longitudinal, 40 < t ≤ 60 mm |
| Elongation (A5) | ≥ 21 | % | Longitudinal, 60 < t ≤ 80 mm |
| Bend test (mandrel diameter) | 3t for t ≤ 25 mm; 4t for t > 25 mm | – | 180° bend, no crack; t = specimen thickness |
DIN 17102 StE255 Hot Rolled Steel Coil Completely Equivalent Material Standards & Substitute Grades
| Country / Region | Standard | Grade | Remarks |
|---|---|---|---|
| Germany | DIN 17102 | StE255 | Original definition; normalized fine-grain steel |
| Germany | DIN EN 10025-3 | S275N | Direct follow-up; normalized delivery, min. yield 275 MPa (t≤16 mm) |
| Europe | EN 10025-3 | S275N | Harmonised European standard; best technical equivalent |
| International | ISO 630-3 | S275N | Identical technical delivery conditions |
DIN 17102 StE255 Hot Rolled Steel Coil Application Introduction
StE255 is designed for welded and bolted steel constructions where moderate strength and good formability are required. It performs reliably under static and moderate dynamic loads. The normalized fine-grain microstructure gives good resistance to brittle fracture and allows use at temperatures down to -20 °C without additional toughness verification (qualities J0) or -50 °C (J2) if agreed.
Typical fields of application:
Product Applications: Welded I‑beams and H‑beams, Welded box girders, Tubular structures and hollow sections, Base plates and stiffeners, Crane runway beams, Offshore module frames, Wind turbine tower shells, Railway wagon underframes
Processed into products: Crane booms and lattice mast sections, Chassis frames for heavy trucks and trailers, Agricultural equipment frames (ploughs, harrows), Bridge girder webs and flanges, Steel‑concrete composite column cascades, Support beams for conveyor systems, Stiffened panel assemblies for ship decks, Ring flanges for tubular towers
Application industries: Civil engineering and building construction, Bridge construction, Crane and lifting equipment, Railway vehicle bodies, Agricultural and forestry machinery, Offshore and marine structures (with supplementary toughness), Wind energy (tower sections), Trailer and chassis manufacturing
DIN 17102 StE255 Hot Rolled Steel Coil Similar / Alternative Material Grades
| Country / Region | Standard | Grade | Remarks |
|---|---|---|---|
| Europe | EN 10025-2 | S275JR/J0/J2 | Non-fine-grain; similar strength, less toughness |
| Europe | EN 10025-4 | S275M/ML | Thermomechanically rolled, higher toughness |
| USA | ASTM A572/A572M | Grade 42 [290] | Yield 290 MPa, similar structural steel |
| USA | ASTM A516/A516M | Grade 65 | Pressure vessel quality, similar tensile strength |
| Japan | JIS G3106 | SM400B | Yield 245 MPa weldable structural steel |
| China | GB/T 1591 | Q275B/C | Approximate yield 275 MPa, fine-grain variant resembles S275N |
Notes:
Welding: StE255 can be welded by all common processes, including SMAW, GMAW, SAW, and resistance welding. Preheating is typically not required for thicknesses below 30 mm, but should follow standard recommendations (e.g., EN 1011-2) based on carbon equivalent (CEV < 0.45).
Post-weld heat treatment: Not normally necessary, though stress relieving may be applied if required by design codes.
Corrosion resistance: The steel has no inherent weathering resistance; unprotected surfaces require coating or galvanizing. For outdoor applications in moderate climates, use of a protective paint system is recommended.
Certification: Inspection certificates per EN 10204 type 2.2, 3.1, or 3.2 can be supplied on request.
- Share
