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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International Mold Steel Flange DH31-EX Die Cast & Forging Steel Flange Product Information
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International Mold Steel Flange DH31-EX Die Cast & Forging Steel Flange Synonyms
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International Mold Steel DH31-EX Die Cast & Forging Steel Product Information
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# **Product Introduction: DH31-EX Premium Hot Work Die Steel for Die Casting and Forging**
## **1. Overview**
**DH31-EX** is a **high-performance, tungsten-alloyed hot work die steel** specifically engineered for extreme applications in aluminum, magnesium, and brass die casting, as well as demanding hot forging operations. Representing an advanced evolution beyond standard H13-type steels, DH31-EX incorporates **tungsten (W) as a key alloying element** to deliver superior **high-temperature strength, thermal fatigue resistance, and resistance to molten metal erosion**. This steel is designed for large, complex dies operating under severe thermal cycling and mechanical stress where maximum die life and minimal thermal deformation are critical requirements. The "EX" designation typically signifies an **extra-high quality grade**, often produced via Electro-Slag Remelting (ESR) for exceptional cleanliness and isotropic properties.
## **2. International Standards & Specifications**
DH31-EX is a proprietary grade that builds upon and exceeds the framework of standard hot work steel classifications, with tungsten addition being a key differentiator.
* **Primary Manufacturer Standard:**
* **International Mold Steel (IMS) DH31-EX:** Proprietary specification for this tungsten-enhanced hot work die steel.
* **Material Classification & Comparative Grades:**
* **Type:** **Tungsten-Chromium-Molybdenum-Vanadium Hot Work Tool Steel.**
* **Performance Benchmark:** An advanced, tungsten-bearing variant related to the **H19 / H10 (AISI)** or **SKD8 / SKD62 (JIS)** family. It offers performance superior to standard H13, particularly in high-temperature strength and tempering resistance.
* **Closest International Equivalents:**
* **AISI H19 (T20819) / DIN 1.2606 (X30WCrV9-3):** The standard tungsten-chromium hot work steel.
* **JIS G4404 SKD8 / SKD62:** Japanese tungsten hot work die steels.
* **European Premium Grades:** Such as **Böhler W321 ISOPLUS** (similar to 1.2365).
* **ISO 4957:** Corresponds to types such as **X30WCrV9** or **X35CrWMoV5**.
## **3. Chemical Composition (Weight %, Typical)**
The composition is characterized by significant tungsten content, which fundamentally alters its high-temperature performance profile.
| Element | Typical Range (%) | Role & Benefit |
| :--- | :--- | :--- |
| **Carbon (C)** | 0.30 – 0.40 | Provides base hardness and strength. Balanced to maintain toughness alongside high alloy content. |
| **Chromium (Cr)** | 2.50 – 3.50 | Provides oxidation resistance and hardenability. Lower than H13, as tungsten assumes the primary high-temperature strengthening role. |
| **Tungsten (W)** | 8.50 – 9.50 | **The defining alloying element.** Provides exceptional **solid-solution strengthening at high temperatures**, dramatically improving **hot hardness (red hardness), tempering resistance, and creep strength**. Also forms stable tungsten carbides. |
| **Molybdenum (Mo)** | 0.50 – 1.50 | Works synergistically with tungsten to enhance hardenability, toughness, and high-temperature strength. |
| **Vanadium (V)** | 0.30 – 0.60 | Forms vanadium carbides for wear resistance and grain refinement. Content is often lower than in H13 due to the dominant role of tungsten. |
| **Silicon (Si)** | 0.80 – 1.20 | Improves oxidation resistance and strengthens the ferrite matrix. |
| **Manganese (Mn)** | 0.20 – 0.50 | Aids in hardenability and deoxidation. |
| **Cobalt (Co)** | (May be present in small amounts) | Sometimes added in premium versions to further enhance hot hardness. |
| **Sulfur (S)** | ≤ 0.005 (Ultra-Low) | Minimized to ensure maximum **toughness and weldability**, critical for large, expensive dies. |
## **4. Typical Physical & Mechanical Properties (Heat Treated)**
* **Recommended Heat Treatment:**
* **Preheating:** 750-800°C (1382-1472°F) - **Crucial** due to high alloy content and risk of thermal shock.
* **Austenitizing (Hardening):** 1080-1150°C (1975-2100°F). The exact temperature is critical and depends on the desired balance of toughness and high-temperature strength.
* **Quenching:** **Air quenching is standard and preferred** due to high hardenability; oil quenching possible for very complex shapes with extreme care.
* **Tempering:** **Double or triple tempering is essential.** Typical tempering range: 560-620°C (1040-1150°F). Exhibits high secondary hardening and exceptional tempering resistance.
* **Mechanical Properties (Hardened & Tempered to ~46-50 HRC):**
* **Hardness (Operating):** 44 – 52 HRC (adjustable via tempering).
* **Tensile Strength:** 1500 – 1700 MPa (218,000 – 247,000 psi)
* **Yield Strength (0.2% Offset):** 1300 – 1500 MPa (188,000 – 218,000 psi)
* **Impact Toughness (Charpy V-Notch):** 25 – 40 J (18 – 29 ft-lb) - Good for its high-temperature capability.
* **Hot Hardness at 600°C (1112°F):** **~48-50 HRC** – **Significantly higher than H13 (~42-45 HRC)**, a key advantage.
* **Hot Hardness at 700°C (1292°F):** Retains useful hardness, where H13 softens considerably.
* **Key Performance Metrics:**
* **Thermal Fatigue Resistance:** **Excellent.** The high hot hardness reduces plastic deformation during thermal cycles, delaying heat check initiation.
* **Tempering/Softening Resistance:** **Outstanding.** Maintains hardness for longer periods under continuous high-temperature exposure.
* **Erosion/Wash-out Resistance:** Very good against molten aluminum and brass, due to high hot hardness.
* **Physical Properties:**
* **Density:** ~8.1 g/cm³ (higher than H13 due to tungsten)
* **Thermal Conductivity:** Slightly lower than H13 (~20-22 W/m·K at 20°C).
* **Coefficient of Thermal Expansion:** ~12.0 x 10⁻⁶/K (20-100°C)
* **Modulus of Elasticity:** ~210 GPa
## **5. Product Application**
DH31-EX is selected for the most severe die casting and forging applications, particularly where high cavity pressure and temperature are involved.
* **High-Pressure Die Casting (Aluminum, Magnesium, Brass):**
* **Cavities and Cores for large, complex structural castings** (e.g., automotive transmission cases, engine blocks, structural frames).
* **Shot Sleeves and Nozzles** for brass and high-temperature aluminum alloys.
* **Unit Dies and Inserts** for high-volume production.
* **Hot Forging (Steel, Titanium, Superalloys):**
* **Forging Dies and Inserts** for high-temperature alloys where die wear and softening are major concerns.
* **Extrusion Dies** for non-ferrous metals at elevated temperatures.
* **Punches and Mandrels** for hot working.
* **Other Demanding Hot Work:**
* **Glass Mold Tooling** for high-temperature glass.
* **Hot Runner System Components** for engineering plastics.
## **6. Key Features & Advantages**
* **Superior High-Temperature Strength & Hardness:** The tungsten addition provides the highest level of hot hardness and tempering resistance among common chromium-based hot work steels, allowing dies to maintain dimensions under load at high temperatures.
* **Enhanced Thermal Fatigue Life:** High hot hardness reduces the magnitude of plastic strain during each thermal cycle, directly extending the time until heat checks initiate.
* **Excellent Resistance to Softening:** Ideal for long production runs where dies are exposed to continuous high temperatures, maintaining performance consistency.
* **Good Toughness for its Hot Strength:** Achieves a viable balance, allowing it to withstand mechanical shock in forging and clamping stresses in die casting.
* **Good Dimensional Stability During Heat Treatment:** When properly processed, exhibits predictable and controllable size change.
* **ESR Quality Available:** Premium "EX" versions offer exceptional homogeneity, cleanliness, and isotropic properties, crucial for large, complex dies.
## **7. Processing Guidelines**
* **Machining:** More difficult than H13 in the annealed state due to higher alloy content and hardness. Requires robust tooling and parameters.
* **Heat Treatment:** **Requires expert knowledge.** Narrower processing window than H13. Must be performed in controlled atmosphere furnaces. **Slow heating and cooling rates are mandatory** to prevent cracking.
* **Welding:** Repairs are challenging but possible with specialized procedures, matching high-temperature filler metals, and thorough pre/post-weld heat treatment.
* **Surface Treatment:** An excellent candidate for **nitriding** and **PVD coatings** (e.g., AlCrN) to further enhance surface performance against soldering and erosion.
**Summary:**
International Mold Steel DH31-EX represents a specialized, high-end solution for the most demanding thermal and mechanical challenges in die casting and forging. Its tungsten-alloyed composition provides a decisive advantage in applications where die temperatures consistently exceed the optimal range for H13-type steels. By offering superior hot hardness and thermal stability, DH31-EX enables longer production runs, reduced maintenance downtime, and the ability to cast or forge more challenging alloys. For manufacturers pushing the limits of process parameters to achieve higher productivity and part quality, DH31-EX provides the necessary die material performance to make such advances viable and reliable.
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International Mold Steel DH31-EX Die Cast & Forging Steel Specification
Dimensions
Size：
Diameter 20-1000 mm Length <7038 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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International Mold Steel DH31-EX Die Cast & Forging Steel Properties
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Applications of International Mold Steel Flange DH31-EX Die Cast & Forging Steel Flange
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Chemical Identifiers International Mold Steel Flange DH31-EX Die Cast & Forging Steel Flange
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Packing of International Mold Steel Flange DH31-EX Die Cast & Forging 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 3509 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
