Project Description
E275K2 (1.0456) is a non-alloy quality steel seamless circular tube specified under EN 10297-1 for mechanical and general engineering applications. The designation “E” identifies a non-alloy engineering steel, “275” denotes the minimum yield strength of 275 MPa, and the suffix “K2” guarantees impact toughness of ≥40 J at −20 °C (longitudinal), making it the proven choice for low-temperature structural and mechanical service. Unlike the basic E275 grade, E275K2 is a fully killed, fine-grain-practised steel with a mandatory minimum aluminium content of 0.020% for grain refinement—the metallurgical foundation for its certified Charpy performance. The K2 subgrade is the only EN 10297-1 275 MPa class that carries a defined notch toughness guarantee at sub-zero temperature. Supplied by FUSHUN METAL under ISO 9001 and AS9120B certified quality management, every heat is delivered with EN 10204 Type 3.1 traceability including Charpy V-notch test reports. E275K2 seamless tubes are widely specified for cold-climate machinery, lifting equipment, agricultural implements, railway rolling stock, and structural fabrications where assured notch toughness at sub-zero temperatures is a mandatory design requirement.
E275K2 — Equivalent Grades
| Standard | Grade | Remarks |
|---|---|---|
| EN 10025-2 | S275K2 | Structural steel — exact equivalent |
| DIN 17100 | St44-3U | Killed steel, comparable impact |
| ASTM | A572 Gr 42 | Approximate strength; no K2 impact class |
| JIS G3106 | SM400B | Welded structure; Charpy at 0 °C |
| ISO 630 | E275D | Quality D: −20 °C impact |
| BS 4360 | Grade 43D | Weather-resistant structural |
Typical Applications of E275K2 Seamless Tubes
Bracing members, columns, truss chords, anchor bolts, and splice-plate connections in outdoor structures where sub-zero Charpy energy is mandated. E275K2 eliminates brittle fracture risk in northern-latitude buildings, pedestrian bridges, and sports stadium frames.
Plough frames, harrow beams, tillage tool bars, loader arms, backhoe dipper sticks, and silage trailer chassis. Absorption of shock and vibration at operating temperatures down to −20 °C without loss of toughness.
Mobile crane lattice booms, tower crane mast sections, forklift mast channels, overhead crane box girders, and spreader beams. Guaranteed −20 °C toughness ensures structural integrity under dynamic lifting and impact loading.
Wagon underframe members, bogie bolster beams, draw-gear components, buffer housings, and container spreader bars. −20 °C Charpy compliance meets UIC and EN 12663 rolling-stock structural requirements.
Wind turbine tower internals, nacelle frames, access platforms, yaw-ring stiffeners, and solar tracker torque tubes. K2-grade Charpy values are routinely required in IEC 61400 wind turbine tower certification.
Bearing housings, spindle carriers, distance bushes, press columns, and machine frames. Killed, fine-grain-practice production provides uniform through-thickness properties and dependable machinability suitable for turning, milling, and drilling.
E275K2 Supply Dimensions
FUSHUN METAL supplies EN 10297-1 E275K2 seamless tubes across three manufacturing routes, with standard delivery in the normalized (+N) condition. As-rolled (+AR) delivery is available on agreement for applications where normalizing will be performed by the fabricator. Incoming dimensional and Charpy verification is performed on every batch sourced from ISO 9001 and AS9120B-certified production lines.
| OD | 26.9 – 660.0 mm |
| WT | 2.6 – 75.0 mm |
| Length | 5.0 – 14.0 m |
| OD | 6.0 – 220.0 mm |
| WT | 0.5 – 30.0 mm |
| Length | 4.0 – 12.5 m |
| OD | 10.0 – 120.0 mm |
| WT | 0.8 – 12.0 mm |
| Length | 4.0 – 12.0 m |
E275K2 Chemical Composition (Ladle Analysis, %)
| C | Si | Mn | P | S | Altot | Cr | Ni | Cu | N |
|---|---|---|---|---|---|---|---|---|---|
| ≤0.20 | ≤0.40 | 0.50–1.40 | ≤0.035 | ≤0.035 | ≥0.020 | ≤0.30 | ≤0.30 | ≤0.35 | ≤0.015 |
Supplemental limits: Mo ≤0.10%, V ≤0.05%, Nb ≤0.05%, Ti ≤0.03%. Microalloying elements (Nb, V, Ti) are present only if agreed at enquiry and their total combined content shall not exceed 0.12%. The mandatory minimum Al (0.020%) ensures the steel is fully killed and fine-grain-practised—this is the metallurgical foundation for the K2 impact guarantee. Compared with basic E275 (Mn ≤1.40% with no minimum), E275K2 imposes a lower Mn band (0.50–1.40%) and tighter residual element control (CEV ≤0.42%), improving both weldability and Charpy shelf energy. FUSHUN METAL verifies chemistry via OES on every incoming heat and retains spectral records for full traceability.
E275K2 Mechanical Properties — Normalized (+N)
| Wall Thickness (mm) | YS ReH (MPa) | TS Rm (MPa) | Elong. A (%) | KV2 −20 °C (J) |
|---|---|---|---|---|
| ≤16 | ≥275 | 410 | ≥22 (L) / ≥20 (T) | ≥40 (L) / ≥27 (T) |
| 16–40 | ≥265 | 410 | ≥22 (L) / ≥20 (T) | ≥40 (L) / ≥27 (T) |
| 40–65 | ≥255 | 410 | ≥22 (L) / ≥20 (T) | ≥40 (L) / ≥27 (T) |
| 65–80 | ≥245 | 380 | ≥22 (L) / ≥20 (T) | ≥40 (L) / ≥27 (T) |
| 80–100 | ≥235 | 380 | ≥22 (L) / ≥20 (T) | ≥40 (L) / ≥27 (T) |
The benchmark distinction of E275K2 over standard E275 is the mandatory −20 °C Charpy V-notch impact requirement: ≥40 J longitudinal, ≥27 J transverse in the normalized (+N) delivery condition. By contrast, basic E275 carries no Charpy guarantee and should not be specified for fracture-critical or dynamically loaded components. Typical Brinell hardness ranges from 120 to 155 HBW. Normalizing is performed at 890–930 °C followed by still-air cooling, producing a uniform ferrite-pearlite microstructure with ASTM grain size 6–8. FUSHUN METAL issues EN 10204 Type 3.1 certification with Charpy results for every shipment.
E275K2 — Additional Product Data
Standard: normalized (+N) at 890–930 °C. Seamless process only (hot-finished, cold-drawn, or cold-rolled). Killed, fine-grain-practice steel, Al ≥0.020%, ASTM E112 grain size 6 or finer. FUSHUN METAL sources exclusively from ISO 9001 and AS9120B-certified mills and performs independent Charpy verification.
Mandatory: ladle analysis, tensile at room temperature, Charpy V-notch at −20 °C (longitudinal, one set per batch), flattening test, dimensional and visual inspection, EN 10204 Type 3.1. Optional: product analysis, transverse Charpy, hardness (Brinell), ultrasonic testing per EN 10893-10, eddy current per EN 10893-2.
Good weldability with all common arc processes (SMAW, GMAW, FCAW, SAW). Recommended preheat ≥100 °C for sections >25 mm or when ambient temperature is below +5 °C. CEV ≤0.42% (typical). Post-weld stress relief at 530–580 °C, hold 1 min/mm. Good cold formability for bending and flaring; HDG-compatible with low Si content (≤0.40%).
Surface options: black (as-rolled), pickled & oiled, bright (cold-finished). Protection: varnish, red-oxide primer, hot-dip galvanising, or FBE coating. Standard pack: hexagonal bundled with steel straps and weatherproof wrapping for sea freight.
