1. Material Composition & Key Properties
Q: What defines the chemical/mechanical properties of E355K2?
A:
Chemical (wt%):
C: ≤0.20 | Mn: 0.90–1.60 | P: ≤0.025 | S: ≤0.020 | Al: ≥0.020 (grain refinement).
Mechanical:
Yield Strength (σᵧ): ≥355 MPa | Tensile (σₜ): 490–630 MPa.
Elongation (A₅): ≥20% | Impact (KV): ≥40J at -20°C (K2 designation).
Note: The "K2" suffix ensures enhanced low-temperature toughness for Arctic/offshore use.
2. Manufacturing & Standards Compliance
Q: How are E355K2 tubes produced and certified?
A:
Process: Primarily seamless (hot-rolled/cold-drawn); welded variants require Charpy testing.
Heat Treatment: Normalized (900–950°C) or Q&T (for thickness >30mm).
Standard Scope: EN 10297-1 for mechanical/structural applications.
3. Dimensional Tolerances
Q: What are the critical dimensional tolerances?
A:
| Parameter | Tolerance | Impact |
|---|---|---|
| OD | ±1.0% (min ±0.5 mm) | Ensures press-fit accuracy |
| Wall Thickness | ±10% (min ±0.4 mm) | Critical for fatigue life |
| Straightness | ≤1.5 mm/m | Vital for rotating shafts |
4. Applications & Limitations
Q: Where is E355K2 typically used?
A:
Low-Temperature: Offshore platforms, Arctic pipelines (K2 toughness).
Heavy Engineering: Hydraulic cylinders, crane jibs (seamless).
Avoid:
Temperatures >500°C (risk of decarburization).
Uncoated use in marine environments.
5. Quality Validation & Certifications
Q: How is quality assured?
A:
Mandatory Tests:
Tensile (EN ISO 6892-1) | Impact (ISO 148-1 at -20°C).
NDT: 100% ultrasonic (EN 10246-1) for seamless tubes.
Certifications: EN 10204 3.2 | PED 2014/68/EU (Category III).
