1,We Manufacturing processes are primarily classified into four types:
1:Forging,
2:Casting,
3:Cutting,
4:Rolling.
2,We can manufacture in accordance with these standards.
Standards:
GB Series (Chinese Standards), JB Series (Machinery Standards), HG Series (Chemical Industry Standards), ASME B16.5 (American Standards), BS4504 (British Standards), DIN (German Standards), and JIS (Japanese Standards).
Internationally, there are two primary systems of pipe flange standards: the European system, represented by the German DIN standards (including those of the former Soviet Union), and the American system, represented by the US ANSI pipe flange standards. Other common standards include: the Chinese Ministry of Machinery Industry standards (JB series), the Ministry of Chemical Industry standards (HG series), the Chinese National Standard *GB/T 9112–9124-2010 Steel Pipe Flanges*, as well as US standards (ASME B16.5), British standards (BS4504), German standards (DIN), Japanese standards (JIS), and marine standards (CBM), among others.
The nominal pressure ratings for the PN series are designated by "PN" and comprise the following nine levels: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160.
The nominal pressure ratings for the Class series are designated by "Class" and comprise the following six levels: Class150, Class300, Class600, Class900, Class1500, and Class2500.
Flange Classification
1. **According to Chemical Industry Standards:** Flanges are classified as follows:
Plate Flat Welding Flange (PL), Necked Flat Welding Flange (SO), Necked Butt Welding Flange (WN), Integral Flange (IF), Socket Welding Flange (SW), Threaded Flange (Th), Butt Welding Ring Loose Flange (PJ/SE), Blind Flange (BL), Flat Welding Ring Loose Flange (PJ/PJ), and Lined Blind Flange (BL(s)).
2. **According to Petrochemical (SH) Industry Standards:** Flanges are classified as follows:
Threaded Flange (PL), Butt Welding Flange (WN), Flat Welding Flange (SO), Socket Welding Flange (SW), Loose Flange (LJ), and Blind Flange (no specific designation).
3. **According to Machinery (JB) Industry Standards:** Flanges are classified as follows:
Integral Flange, Butt Welding Flange, Plate Flat Welding Flange, Butt Welding Ring Plate Loose Flange, Flat Welding Ring Plate Loose Flange, Lap Joint Ring Plate Loose Flange, and Blind Flange.
4. **According to Connection Method/Type:** Flanges are classified as follows:
Plate Flat Welding Flange, Necked Flat Welding Flange, Necked Butt Welding Flange, Socket Welding Flange, Threaded Flange, Blind Flange, Necked Butt Welding Ring Loose Flange, Flat Welding Ring Loose Flange, Ring-Type Joint (RTJ) Flange and Blind Flange, Large-Diameter Plate Flange, Large-Diameter High-Neck Flange, Figure-8 Blind Plate, Butt Welding Ring Loose Flange, etc.
5. **According to the Component Being Connected:** Flanges can be classified into Vessel Flanges and Pipe Flanges.
6. **According to Structural Type:** Flanges include Integral Flanges, Threaded Flanges, Flat Welding Flanges, Butt Welding Flanges, Lap Joint (Loose/Swivel) Flanges, and Blind Flanges.
A flange—also referred to as a flange plate or rim—is a component used to connect shafts to one another, or, more commonly, to join the ends of pipes. Flanges are also utilized at the inlet and outlet ports of equipment to facilitate connections between two devices—for instance, the flange on a speed reducer. A "flange connection" or "flanged joint" refers to a detachable joint assembly comprising three interconnected elements—a flange, a gasket, and bolts—that together form a sealed structural unit. In the context of piping systems, a "pipe flange" specifically denotes a flange used for plumbing within the installation; when applied to equipment, it refers to the inlet or outlet flange of that specific device. Flanges feature a series of holes through which bolts are inserted to securely fasten the two flanges together, while a gasket placed between the flanges ensures a leak-proof seal. Flanges are broadly categorized into three types: threaded (screw-in) flanges, welded flanges, and clamp-type flanges. Flanges are invariably used in pairs; threaded flanges are suitable for low-pressure piping applications, whereas welded flanges are required for systems operating at pressures exceeding 4 kilograms per square centimeter. A sealing gasket is inserted between the two flange plates, which are then firmly secured using bolts. The thickness of a flange—as well as the specifications of the bolts used to fasten it—vary depending on the specific pressure rating required for the application. When connecting equipment such as water pumps or valves to piping systems, the corresponding connection points on these devices are often manufactured in the shape of a matching flange; this method of attachment is also referred to as a "flange connection." Generally, any connecting component that utilizes bolts to join and seal the perimeters of two flat surfaces—such as the joints in ventilation ducts—is termed a "flange"; such components may collectively be classified as "flange-type parts." However, since such a connection often constitutes merely a *portion* of a larger device—for instance, the interface between a flange and a water pump—it would be inappropriate to classify the entire water pump itself as a "flange-type part." Conversely, smaller components—such as valves—that feature such flanged interfaces may indeed be appropriately categorized as "flange-type parts."
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EN S355K2G4 High Manganese, Structural, Hot Rolled, Quality Steel Flange Product Information
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EN S355K2G4 High Manganese, Structural, Hot Rolled, Quality Steel Flange Synonyms
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EN S355K2G4 High Manganese, Structural, Hot Rolled, Quality Steel Product Information
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# **Product Name:** EN S355K2G4 (S355K2+M) Structural Steel, Thermomechanically Rolled, High-Toughness Grade
**Overview**
EN S355K2G4 is a **premium thermomechanically controlled processed (TMCP), fine-grained structural steel** specified under EN 10025-4. The "K2G4" designation indicates a material with **enhanced guaranteed impact toughness at -20°C (K2 quality)**, supplied in the **thermomechanically rolled condition (G4 or +M)**. This grade represents the optimal synergy of modern metallurgy and processing, delivering an exceptional combination of high strength, superior fracture resistance at low temperatures, and excellent weldability without a separate heat treatment. It is specifically designed for the most critical welded structures where weight optimization, fabrication efficiency, and uncompromising safety in cold environments are paramount. It is **not a "High Manganese" steel**; its properties are achieved through advanced TMCP technology, microalloying, and grain refinement.
**Key International Standards**
* **Primary Standard:** **EN 10025-4:2019** - Hot rolled products of structural steels - Part 4: Technical delivery conditions for thermomechanical rolled weldable fine grain structural steels.
* **Grade & Condition Designation:** **S355K2G4** or **S355K2+M**
* **S:** Structural Steel.
* **355:** Minimum yield strength (ReH) in MPa for thicknesses **≤ 16 mm**.
* **K2:** **Superior quality designation.** Guarantees a higher minimum impact energy at **-20°C** compared to the standard J2 grade.
* **G4/M:** Indicates **thermomechanical rolling (TMCP, M)**.
* **Key Distinction:** The "K2" quality is the **toughest standard quality** within the EN 10025 series for -20°C service, requiring a higher absorbed impact energy. Combined with the benefits of TMCP (low CEV), it offers a best-in-class balance for critical applications.
* **Common International Equivalents:**
* **ASTM:** **A841 Grade B** (TMCP plate) with supplemental toughness requirements.
* **GB/T:** **Q355D/E** (TMCP variants).
* **Specialized:** Fully compliant with demanding specifications such as **EN 10225** for offshore structures and various **national bridge standards**.
**Chemical Composition (Ladle Analysis, % by weight, typical for high-toughness TMCP steel)**
Lean, clean chemistry optimized for TMCP response and maximum toughness.
* **Carbon (C):** **Low, typically ≤ 0.10%** (Essential for low CEV and high toughness).
* **Manganese (Mn):** **1.40% - 1.60%** (Balanced for strength with minimal CEV impact).
* **Phosphorus (P):** ≤ **0.020%** (Very low).
* **Sulphur (S):** ≤ **0.005%** (Extremely low, often calcium-treated for inclusion shape control).
* **Silicon (Si):** ≤ **0.40%**.
* **Aluminum (Alt):** ≥ **0.020%** (For grain refinement).
* **Microalloys (Nb, Ti, V):** Precisely added (e.g., Nb 0.02-0.05%, Ti 0.01-0.02%) to control austenite conditioning and precipitation during TMCP.
* **Carbon Equivalent (CEV):** **Very low, typically ≤ 0.36**. This is a **fundamental advantage**, drastically improving weldability by reducing pre-heat requirements and hydrogen cracking sensitivity.
**Physical & Mechanical Properties (for thermomechanical condition, thickness ≤ 16mm)**
* **Yield Strength (ReH):** ≥ **355 MPa** (Minimum for t ≤ 16mm; thickness-dependent).
* **Tensile Strength (Rm):** **470 - 630 MPa**.
* **Elongation at Break (A5):** ≥ **21%** (Minimum, typically higher).
* **Impact Energy (KV):** **≥ 40 J at -20°C** (Longitudinal, Charpy V-notch). **This is the defining K2 property (≥40J), superior to the 27J of J2 grades.** Actual values often exceed 60J.
* **Fine Grain Size:** Extremely fine, typically **ASTM 10 or finer**.
* **Yield-to-Tensile Ratio:** Typically <0.85, indicating good plastic deformation capacity.
* **Density:** **~7.85 g/cm³**.
* **Modulus of Elasticity:** **210 GPa**.
**Product Features**
1. **Superior Fracture Toughness (K2 Quality):** Provides the highest standard-guaranteed impact energy at -20°C within the S355 TMCP family, offering an extra safety margin against brittle fracture for critical components.
2. **Excellent Weldability (Key Feature):** The **very low carbon equivalent (CEV)** allows for welding with **significantly lower or no pre-heat**, simplifies procedure qualification, reduces fabrication time and cost, and minimizes the risk of hydrogen-induced cold cracking—a major advantage for on-site construction.
3. **TMCP Efficiency:** Achieves this high level of strength and toughness in-line during rolling, eliminating the energy consumption of normalizing.
4. **Homogeneous, Fine-Grained Structure:** The controlled process results in a very uniform microstructure with excellent through-thickness properties.
**Typical Applications**
S355K2G4 is the material of choice for modern, high-integrity structures in demanding environments.
* **Offshore Wind & Oil & Gas:** **Monopile transitions, jacket nodes, floating platform components**—where weldability and toughness are critical for fatigue life and safety.
* **Critical Bridge Construction:** **Welded box girders, orthotropic decks, and splice plates** for major bridges in cold climates or seismic zones.
* **Shipbuilding (High-Value Vessels):** **Ice-class hull structures, liquefied gas carrier support systems**.
* **Heavy Mobile Equipment:** **Critical welded frames and booms** for cranes and excavators operating in Arctic conditions.
* **Building Construction:** **Seismic moment-resisting frames and diagrid nodes** in high-rise buildings.
**Available Forms & Processing**
* **Forms:** Primarily supplied as **thermomechanically rolled plates**. Available in wider thickness ranges than normalized grades.
* **Surface:** With standard mill scale. Often supplied as shot blasted and primed for critical projects.
* **Processing:** Excellent for all cutting and welding. **Medium-low heat input welding processes are recommended** to preserve the fine-grained HAZ microstructure. Good cold forming capability.
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**Critical Procurement Note**
* **Specify Correct Standard:** Ensure reference to **EN 10025-4**. The "K2" quality is specific to fine-grained steels (Parts 3 & 4).
* **Thickness-Dependent Strength:** Use the correct guaranteed yield strength from EN 10025-4 tables for the product thickness.
* **Explicit Toughness Requirement:** Ordering "K2" explicitly demands the higher impact value (≥40J). This is not the default; S355J2G4 is the standard TMCP grade.
* **Welding Advantage:** The low CEV should be actively leveraged in fabrication planning to optimize costs and schedules.
* **Not "High Manganese":** This term is incorrect. The correct classification is **"Thermomechanically Rolled Fine Grain Structural Steel with Enhanced -20°C Toughness (K2 Quality)."**
* **Certification:** Supplied with a full **Inspection Certificate 3.1/3.2**, including chemistry (noting low CEV), mechanical properties, and impact tests **at -20°C verifying the ≥40J K2 requirement**. Supplementary through-thickness (Z) testing is common for thick plate.
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EN S355K2G4 High Manganese, Structural, Hot Rolled, Quality Steel Specification
Dimensions
Size：
Diameter 20-1000 mm Length <5840 mm
Size:We can customized as required
Standard：
Per your request or drawing
We can customized as required
Properties（Theoretical）
Chemical Composition
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EN S355K2G4 High Manganese, Structural, Hot Rolled, Quality Steel Properties
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Applications of EN S355K2G4 High Manganese, Structural, Hot Rolled, Quality Steel Flange
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Chemical Identifiers EN S355K2G4 High Manganese, Structural, Hot Rolled, Quality Steel Flange
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Packing of EN S355K2G4 High Manganese, Structural, Hot Rolled, Quality Steel Flange
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Standard Packing:
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Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Flange drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 2311 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition
