International Mold Steel Sheet,Plate,DH31-EX Die Cast & Forging Steel Sheet,Plate

International Mold Steel Sheet/Plate DH31-EX Die Cast & Forging Steel Sheet/Plate Product Information -:- For detailed product information, please contact sales. -: International Mold Steel Sheet/Plate DH31-EX Die Cast & Forging Steel Sheet/Plate Synonyms -:- For detailed product information, please contact sales. -:

International Mold Steel DH31-EX Die Cast & Forging Steel Product Information -:- For detailed product information, please contact sales. -: # **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. -:- For detailed product information, please contact sales. -: 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 -:- For detailed product information, please contact sales. -: International Mold Steel DH31-EX Die Cast & Forging Steel Properties -:- For detailed product information, please contact sales. -:

Applications of International Mold Steel Sheet,Plate DH31-EX Die Cast & Forging Steel Sheet,Plate -:- For detailed product information, please contact sales. -: Chemical Identifiers International Mold Steel Sheet,Plate DH31-EX Die Cast & Forging Steel Sheet,Plate -:- For detailed product information, please contact sales. -:

Packing of International Mold Steel Sheet/Plate DH31-EX Die Cast & Forging Steel Sheet/Plate -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Sheet/Plate 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