Cast Stainless Steel Sheet,Plate HK40, ACI

Cast Stainless Steel Sheet/Plate HK40, ACI Product Information -:- For detailed product information, please contact sales. -: Cast Stainless Steel Sheet/Plate HK40, ACI Synonyms -:- For detailed product information, please contact sales. -:

Cast Stainless Steel HK40, ACI Product Information -:- For detailed product information, please contact sales. -: ### **Technical Data Sheet: Cast Stainless Steel ACI HK-40** **Product Overview** ACI HK-40 is a high-carbon, austenitic heat-resistant cast steel defined by the Alloy Casting Institute (ACI). It is renowned for its exceptional high-temperature strength, outstanding resistance to oxidation (scaling), and good resistance to carburizing atmospheres. The "HK" designation signifies the 25% Chromium - 12% Nickel family, and the "40" indicates a nominal carbon content of 0.40%. This elevated carbon content is the key differentiator from HK30, providing superior creep and rupture strength, making HK-40 a premier choice for heavily loaded components in prolonged high-temperature service. --- #### **1. International Standards & Designations** ACI HK-40 is recognized globally under several major standards systems. | Standard Organization | Designation | Key Scope / Note | | :--- | :--- | :--- | | **ACI / SFSA (USA)** | **HK-40** | **Foundational Specification** | | **UNS (Unified Numbering System)** | **J94204** | Unified Number | | **ASTM International** | A297 Grade HK40 | General Heat-Resistant Castings | | **ASTM International** | A351/A351M Grade HK40 | Pressure-Containing Parts | | **European Norm (EN)** | **1.4848** | EN 10295 (Commonly used equivalent) | | **German (DIN)** | **G-X 40 CrNiSi 25-12** | - | | **Japanese (JIS)** | **SCH 22** | JIS G5121 | --- #### **2. Chemical Composition (Weight % per ACI)** The chemical composition is precisely balanced to deliver optimal high-temperature performance. | Element | Composition (%) | | :--- | :--- | | **Carbon (C)** | 0.35 - 0.45 | | **Chromium (Cr)** | 23.0 - 27.0 | | **Nickel (Ni)** | 19.0 - 22.0 | | **Silicon (Si)** | 1.75 max | | **Manganese (Mn)** | 2.00 max | | **Phosphorus (P)** | 0.04 max | | **Sulfur (S)** | 0.04 max | | **Iron (Fe)** | Balance | **Key Composition Rationale:** * **Chromium (Cr):** Forms a dense, adherent surface layer of chromium oxide (Cr₂O₃) that provides exceptional protection against oxidation and carburization at temperatures up to **1150°C (2100°F)**. * **Nickel (Ni):** Stabilizes the face-centered cubic (FCC) austenitic matrix, which provides inherent high-temperature strength, ductility, and remarkable resistance to thermal fatigue and creep deformation. * **Carbon (C):** The high carbon content is critical for enhancing elevated temperature strength. It contributes to solid solution strengthening and promotes the formation of stable chromium carbides, which significantly improve creep and rupture resistance. --- #### **3. Typical Physical & Mechanical Properties** **Physical Properties (At Room Temperature):** * **Density:** 7.78 g/cm³ (0.281 lb/in³) * **Melting Range:** ~1350 - 1400 °C (2460 - 2550 °F) * **Specific Heat:** 500 J/kg·K * **Thermal Conductivity:** ~14.0 W/m·K (at 100°C) * **Coefficient of Thermal Expansion:** ~16.0 x 10⁻⁶ /K (20 - 100°C) **Room Temperature Mechanical Properties (As-Cast or Heat-Treated):** * **Tensile Strength:** 620 MPa (90 ksi) min * **Yield Strength (0.2% Offset):** 310 MPa (45 ksi) min * **Elongation (% in 2in/50mm):** 10% min * **Hardness (Brinell):** 170 - 240 HB **High-Temperature Performance:** * **Oxidation Resistance:** Excellent, capable of withstanding continuous operation in oxidizing furnace atmospheres up to 1150°C. * **Creep & Rupture Strength:** Outstanding. HK-40 offers superior long-term load-bearing capability at high temperatures compared to lower-carbon grades like HK-30, making it ideal for pressure-containing parts. * **Carburization Resistance:** Good resistance to degradation in carbon-rich environments, such as those found in carburizing furnaces. --- #### **4. Product Applications** ACI HK-40 is utilized for complex, static cast components that operate under high mechanical loads and severe thermal conditions. **Primary Industry Applications:** * **Petrochemical & Refining:** * Fittings, valves, and pump casings for reformer furnace systems. * Tube headers, return bends, and manifolds. * Reactor components. * **Heat Treatment & Industrial Furnaces:** * Radiant tubes, retorts, and muffles. * Furnace trays, baskets, and grid fixtures. * Carburizing boxes and fixtures. * **Power Generation:** * Components for boiler systems and waste-to-energy plants. * High-temperature burner parts and support systems. --- #### **5. Fabrication & Heat Treatment** * **Casting:** Excellently suited for all static casting methods, including sand casting and investment casting, to produce intricate shapes. * **Machining:** Challenging due to its austenitic toughness, work-hardening tendency, and abrasive carbides. Requires powerful machinery, rigid setups, carbide tooling, and appropriate cutting parameters. * **Welding:** Weldable using processes like SMAW (Stick) and GTAW (TIG). Matching or over-alloyed filler metals (e.g., ENiCrFe-3) are recommended. **Post-weld heat treatment (Solution Annealing) is crucial** to dissolve detrimental carbides precipitated in the heat-affected zone and restore maximum ductility and corrosion resistance. * **Heat Treatment:** The standard practice is **Solution Annealing** at **1149°C - 1204°C (2100°F - 2200°F)**, followed by rapid cooling (water quench or fast air). This treatment ensures carbides are dissolved into the austenitic matrix, achieving optimal high-temperature properties and ductility. --- **Disclaimer:** The information provided herein is for reference purposes. Material properties can vary based on casting section size, heat treatment, and foundry process. For critical applications, consultation with the material supplier and reference to the full, published ACI and ASTM specifications is essential. -:- For detailed product information, please contact sales. -: Cast Stainless Steel HK40, ACI Specification Dimensions Size： Diameter 20-1000 mm Length <4217 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. -: Cast Stainless Steel HK40, ACI Properties -:- For detailed product information, please contact sales. -:

Applications of Cast Stainless Steel Sheet,Plate HK40, ACI -:- For detailed product information, please contact sales. -: Chemical Identifiers Cast Stainless Steel Sheet,Plate HK40, ACI -:- For detailed product information, please contact sales. -:

Packing of Cast Stainless Steel Sheet/Plate HK40, ACI -:- 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 688 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