AISI Type H43 Hot Work Tool Steel Rod/Bar (UNS T20843)

AISI Type H43 Hot Work Tool Steel Rod (UNS T20843) Product Information -:- For detailed product information, please contact sales. -: AISI Type H43 Hot Work Tool Steel Rod (UNS T20843) Synonyms -:- For detailed product information, please contact sales. -:

AISI Type H43 Hot Work Tool Steel (UNS T20843) Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: AISI Type H43 (UNS T20843) Hot Work Tool Steel** **Overview** AISI Type H43 is a tungsten-based hot work tool steel designed for exceptional high-temperature strength, hardness retention, and resistance to thermal fatigue (heat checking). Its key characteristic is **secondary hardening**, a phenomenon where its hardness actually increases upon tempering at high temperatures (typically between 500°C - 600°C / 930°F - 1110°F). This makes H43 an outstanding choice for demanding applications involving high-pressure die casting, extrusion, and forging tools exposed to severe thermal cycling and abrasive wear. **Key Advantages** * **Superior Hot Hardness:** Maintains high hardness and strength at elevated service temperatures (up to ~650°C / 1200°F), outperforming many chromium-based hot work steels. * **Excellent Resistance to Thermal Fatigue & Heat Checking:** Withstands repeated heating and cooling cycles without developing a network of surface cracks. * **Good Wear Resistance & Erosion Resistance:** Ideal for applications involving abrasive materials or high-velocity molten metal flows. * **High Tempering Resistance:** Exhibits secondary hardening, allowing it to be tempered at high temperatures for optimal toughness and stability. **International Designations & Standards** * **AISI (USA):** H43 * **UNS (USA):** T20843 * **ASTM (USA):** A681 (specifies H43) * **DIN (Germany):** ~1.2606 (Similar tungsten hot-work steel, not a direct equivalent) * **JIS (Japan):** SKD6 (Similar tungsten hot-work steel) *(Note: While H43 is standardized in the U.S., exact equivalents in other standards may vary slightly. H43 is part of the tungsten-series hot work steels, distinct from the more common H11-H19 chromium series.)* --- #### **1. Chemical Composition (Typical, Weight %)** The high tungsten and molybdenum content are responsible for its exceptional hot hardness and secondary hardening. | Element | Content (%) | Role & Effect | | :--- | :--- | :--- | | **Carbon (C)** | 0.50 - 0.65 | Provides base hardness and wear resistance. | | **Tungsten (W)** | 8.50 - 10.00 | **Primary alloying element.** Forms stable carbides, enabling exceptional high-temperature strength and secondary hardening. | | **Chromium (Cr)** | 3.75 - 4.50 | Enhances hardenability, provides moderate corrosion/oxidation resistance, and contributes to wear resistance. | | **Molybdenum (Mo)**| 1.75 - 2.20 | Increases hardenability, refines grain structure, and works synergistically with tungsten for high-temperature performance. | | **Vanadium (V)** | 1.80 - 2.20 | Forms very hard, fine carbides that significantly improve wear resistance and grain refinement. | | **Silicon (Si)** | 0.80 - 1.20 | Improves oxidation resistance and strengthens the ferrite matrix. | | **Manganese (Mn)** | 0.15 - 0.40 | Aids in deoxidation during steelmaking and enhances hardenability. | | **Sulfur (S)** | ≤ 0.030 | Residual (kept low). | | **Phosphorus (P)** | ≤ 0.030 | Residual (kept low). | | **Iron (Fe)** | Balance | Base metal. | --- #### **2. Physical & Mechanical Properties** *Note: Properties are highly dependent on heat treatment condition.* | Property | Value / Description | Condition / Note | | :--- | :--- | :--- | | **Density** | ~8.0 g/cm³ (0.29 lb/in³) | Annealed | | **Melting Point** | ~1427°C (2600°F) | Approximate | | **Thermal Conductivity** | 26-30 W/m·K | At 20°C | | **Coefficient of Thermal Expansion** | 11.5 x 10⁻⁶/K | 20-600°C | | **Hardness (Annealed)** | ~207-235 HB | Brinell, typical annealed condition | | **Hardness (Hardened & Tempered)** | **45 - 55 HRC** | Typical working hardness range. Can achieve **up to ~58 HRC** via secondary hardening tempering. | | **Tempering Temperature Range** | **540°C - 650°C (1000°F - 1200°F)** | **Critical:** Peak secondary hardening occurs in this range. | | **Machinability** | 55-60% (of 1% carbon steel) | Annealed condition. Lower machinability compared to chromium hot-work steels. | --- #### **3. Product Applications** AISI H43 is primarily used for critical components in high-temperature metalforming processes where extreme hot hardness is required. * **High-Pressure Die Casting (HPDC):** * Cores and inserts for aluminum, magnesium, and brass die casting. * Nozzles, goosenecks, and plunger tips (especially for brass). * **Extrusion Tooling:** * Dies, dummy blocks, and liners for **copper and brass extrusion** (where temperatures are very high). * Mandrels and backers for heavy-duty extrusion. * **Hot Forging:** * Dies and inserts for forging highly abrasive or high-temperature alloys. * Piercing punches and wear pads. * **Other Applications:** * Glass molding tools. * Hot shear blades for cutting at high temperatures. * Components in plastic injection molding for abrasive or high-temperature engineering resins. --- #### **4. Heat Treatment Guidelines (Typical)** * **Preheating:** **Mandatory.** Double preheat at 650°C (1200°F) and 850°C (1560°F) to minimize thermal stress. * **Austenitizing (Hardening):** **1020°C - 1070°C (1870°F - 1960°F)**, followed by oil or salt bath quenching. **Note:** Very high hardening temperature requires careful furnace control. * **Tempering:** **Immediately after quenching.** Temper **at least twice** within the range of **540°C - 650°C (1000°F - 1200°F)**. Hold for 2 hours per inch of thickness. The hardness will peak (secondary hardening) typically between 570°C - 600°C (1060°F - 1110°F). **Disclaimer:** This information is for reference purposes. Always consult the specific material data sheet from your steel supplier and a professional heat treater for precise processing parameters for your application. -:- For detailed product information, please contact sales. -: AISI Type H43 Hot Work Tool Steel (UNS T20843) Specification Dimensions Size： Diameter 20-1000 mm Length <6703 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. -: AISI Type H43 Hot Work Tool Steel (UNS T20843) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI Type H43 Hot Work Tool Steel Rod (UNS T20843) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI Type H43 Hot Work Tool Steel Rod (UNS T20843) -:- For detailed product information, please contact sales. -:

Packing of AISI Type H43 Hot Work Tool Steel Rod (UNS T20843) -:- 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 Rod 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 3174 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