Cast Stainless Steel Seamless tube HK40, ASTM A608

Cast Stainless Steel Seamless tube HK40, ASTM A608 Product Information -:- For detailed product information, please contact sales. -: Cast Stainless Steel Seamless tube HK40, ASTM A608 Synonyms -:- For detailed product information, please contact sales. -:

Cast Stainless Steel HK40, ASTM A608 Product Information -:- For detailed product information, please contact sales. -: ### **Technical Data Sheet: Cast Stainless Steel HK40 (ASTM A608 Grade HK40)** **Product Overview** ASTM A608 Grade HK40 is a high-carbon, austenitic heat-resistant steel specification for centrifugal castings intended for high-temperature service. The "HK" designation represents the 25% chromium - 20% nickel alloy family, while "40" indicates the nominal 0.40% carbon content. This specification covers requirements for centrifugally cast steel tubes, pipes, and cylinders that must withstand extreme temperatures, pressure, and corrosive environments, making it the premier choice for reformer tubes, radiant tubes, and other critical high-temperature applications. --- #### **1. International Standards & Designations** ASTM A608 HK40 is recognized under various international standards: | Standard Organization | Designation | | :--- | :--- | | **ASTM International** | **A608 Grade HK40** | | **UNS (Unified Numbering System)** | **J94204** | | **ACI/SFSA (USA)** | **HK-40** | | **European Norm (EN)** | 1.4848 | | **German (DIN)** | G-X 40 CrNiSi 25-12 | | **Japanese (JIS)** | SCH 22 | --- #### **2. Chemical Composition (Weight % per ASTM A608)** The chemical composition is strictly controlled to ensure 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)** | 2.00 max | | **Manganese (Mn)** | 2.00 max | | **Phosphorus (P)** | 0.04 max | | **Sulfur (S)** | 0.04 max | | **Iron (Fe)** | Balance | **Key Composition Features:** - **Elevated Carbon**: Provides superior creep and rupture strength through solid solution strengthening - **High Chromium**: Ensures exceptional oxidation and carburization resistance - **Nickel Content**: Maintains austenitic structure stability under thermal cycling --- #### **3. Typical Physical & Mechanical Properties** **Physical Properties:** - **Density**: 7.78 g/cm³ (0.281 lb/in³) - **Melting Range**: 1350-1400°C (2460-2550°F) - **Thermal Conductivity**: 14.0 W/m·K at 100°C - **Specific Heat**: 500 J/kg·K - **Coefficient of Thermal Expansion**: 16.5 × 10⁻⁶ /K (20-540°C) - **Modulus of Elasticity**: 200 GPa at 20°C **Mechanical Properties (Per ASTM A608):** - **Tensile Strength**: 485 MPa (70 ksi) minimum - **Yield Strength (0.2% Offset)**: 240 MPa (35 ksi) minimum - **Elongation**: 8.0% minimum in 2 inches - **Hardness**: 170-240 HB **High-Temperature Performance:** - **Maximum Service Temperature**: 1150°C (2100°F) - **Creep Strength**: Excellent long-term load-bearing capability - **Oxidation Resistance**: Superior performance in oxidizing atmospheres - **Carburization Resistance**: Good resistance to carbon penetration --- #### **4. Product Applications** ASTM A608 HK40 is specifically designed for centrifugally cast tubular products in severe service environments: **Petrochemical Industry:** - Steam methane reformer tubes - Ethylene cracking furnace tubes - Pyrolysis heater tubes - Reformer outlet headers and pigtails **Heat Processing Equipment:** - Radiant tubes for heat treatment furnaces - Carburizing retorts and muffles - Annealing furnace tubes - Roller hearth furnace components **Power Generation:** - Waste heat boiler components - Biomass energy conversion systems - High-temperature piping systems --- #### **5. Manufacturing & Fabrication** **Casting Process:** - Produced by centrifugal casting method - Creates seamless, uniform wall thickness tubes - Excellent dimensional control and surface finish **Heat Treatment Requirements:** - Solution annealing temperature: 1150°C (2100°F) minimum - Rapid cooling to prevent carbide precipitation - Heat treatment is mandatory per ASTM A608 **Machining Characteristics:** - Difficult to machine due to work hardening - Requires carbide tooling and rigid setups - Slow speeds with heavy feeds recommended **Welding Considerations:** - Weldable using SMAW and GTAW processes - Matching filler metals (ENiCrFe-3 type) required - Post-weld heat treatment essential --- #### **6. Quality Assurance** ASTM A608 mandates: - Chemical analysis for each heat - Tensile testing from each lot - Hydrostatic or non-destructive testing - Microstructural examination - Dimensional verification --- **Technical Notes:** - ASTM A608 HK40 offers superior creep strength compared to lower-carbon grades - The centrifugal casting process provides enhanced metallurgical integrity - Proper heat treatment is critical for maximizing service life - Regular microstructural analysis recommended during service *This information is for reference purposes. For complete requirements, consult the latest ASTM A608 specification and qualified metallurgical engineering resources.* -:- For detailed product information, please contact sales. -: Cast Stainless Steel HK40, ASTM A608 Specification Dimensions Size： Diameter 20-1000 mm Length <4219 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, ASTM A608 Properties -:- For detailed product information, please contact sales. -:

Applications of Cast Stainless Steel Seamless tube HK40, ASTM A608 -:- For detailed product information, please contact sales. -: Chemical Identifiers Cast Stainless Steel Seamless tube HK40, ASTM A608 -:- For detailed product information, please contact sales. -:

Packing of Cast Stainless Steel Seamless tube HK40, ASTM A608 -:- 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 Seamless tube 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 690 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