Cast Stainless Steel Seamless tube HK30, ASTM A608

Cast Stainless Steel Seamless tube HK30, ASTM A608 Product Information -:- For detailed product information, please contact sales. -: Cast Stainless Steel Seamless tube HK30, ASTM A608 Synonyms -:- For detailed product information, please contact sales. -:

Cast Stainless Steel HK30, ASTM A608 Product Information -:- For detailed product information, please contact sales. -: ### **Technical Data Sheet: Cast Stainless Steel HK30 (ASTM A608 Grade HK30)** **Product Overview** Cast Stainless Steel HK30, conforming to the ASTM A608 standard, is a high-carbon, austenitic heat-resistant alloy specifically designed for high-temperature service. The "HK" designation originates from the Alloy Casting Institute (ACI), and the "30" refers to its nominal carbon content of 0.30%. ASTM A608 is the key standard governing centrifugally cast steel tubes for use in high-temperature pressure applications, making HK30 a premier choice for critical components like radiant tubes and reformer tubes that must withstand extreme heat, pressure, and corrosive environments. --- #### **1. International Standards & Designations** HK30 is recognized under several international standards. Its primary identity for centrifugal casting is ASTM A608. | Standard Organization | Designation | Scope / Note | | :--- | :--- | :--- | | **ASTM International** | **A608 Grade HK30** | **Primary Standard for Centrifugal Castings** | | **ASTM International** | A297 Grade HK30 | For static castings | | **UNS (Unified Numbering System)** | **J94203** | Unified Number | | **ACI / SFSA (USA)** | **HK-30** | Common Trade Designation | | **European Norm (EN)** | **1.4836** | EN 10295 | | **German (DIN)** | **G-X 40 CrNiSi 25-12** | - | | **Japanese (JIS)** | **SCH 21** | - | --- #### **2. Chemical Composition (Weight % per ASTM A608)** The chemical composition is the foundation of HK30's high-temperature performance, strictly controlled by the ASTM A608 specification. | Element | Composition (%) | | :--- | :--- | | **Carbon (C)** | 0.25 - 0.35 | | **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 Rationale:** * **High Chromium (Cr):** Imparts exceptional resistance to oxidation (scaling) and carburization at temperatures up to 1150°C by forming a stable, protective chromium oxide (Cr₂O₃) layer. * **High Nickel (Ni):** Stabilizes the austenitic phase, providing excellent creep strength, structural stability, and resistance to thermal fatigue and cycling. * **Controlled Carbon (C):** The elevated carbon content significantly enhances high-temperature strength and creep resistance through solid solution strengthening. --- #### **3. Typical Physical & Mechanical Properties** **Physical Properties (At Room Temperature):** * **Density:** 7.78 g/cm³ (0.281 lb/in³) * **Melting Range:** ~1390 - 1435 °C (2535 - 2615 °F) * **Specific Heat:** 500 J/kg·K * **Thermal Conductivity:** ~14.5 W/m·K (at 100°C) * **Coefficient of Thermal Expansion:** ~16.5 x 10⁻⁶ /K (20 - 540°C) **Mechanical Properties (Per ASTM A608 - As-Cast or Heat-Treated Condition):** * **Tensile Strength:** 485 MPa (70 ksi) min * **Yield Strength (0.2% Offset):** 240 MPa (35 ksi) min * **Elongation (% in 2in/50mm):** 8.0% min **High-Temperature Performance (Key Characteristics):** * **Maximum Service Temperature:** Up to **1150°C (2100°F)** in oxidizing environments. * **Oxidation Resistance:** Excellent, making it suitable for long-term service in direct-fired furnaces. * **Creep & Rupture Strength:** Outstanding resistance to deformation under sustained mechanical load at high temperatures, which is the primary reason for its use in pressure-bearing components like tubes. * **Carburization Resistance:** Good resistance to attack from carbon-rich atmospheres, commonly encountered in heat-treating processes. --- #### **4. Product Applications** ASTM A608 HK30 is predominantly used for **centrifugally cast tubes** and other cylindrical components that operate under high pressure and temperature. Its primary applications are in: * **Petrochemical & Refining:** * **Steam Methane Reformer (SMR) Tubes**: The most critical application. * Ethylene Cracker Tubes (Transfer Line Exchangers) * Heater and Furnace Tubes in direct-fired service. * **Heat Treatment & Industrial Furnaces:** * **Radiant Tubes** (for carburizing, annealing, and normalizing furnaces) * Rollers and Muffles * Retorts and Fixtures * **Power Generation:** * Tubing for waste-to-energy and biomass boilers. * High-temperature burner components and supports. --- #### **5. Fabrication & Heat Treatment** * **Casting Process:** Primarily produced via **Centrifugal Casting** to create seamless, hollow cylinders with a uniform wall structure, as mandated by ASTM A608. * **Machining:** Difficult due to its toughness and work-hardening nature. Requires carbide tools, slow speeds, and heavy feeds. * **Welding:** Can be welded using processes like SMAW (Stick) and GTAW (TIG) with matching or over-alloyed filler metals (e.g., ENiCrFe-3). Strict control of heat input and post-weld heat treatment is crucial. * **Heat Treatment:** ASTM A608 requires the material to be supplied in the heat-treated condition. The standard treatment is **Solution Annealing** at a minimum temperature of **1150°C (2100°F)**, followed by rapid cooling (water quench or fast air) to put carbides into solution and ensure optimal high-temperature properties. --- **Disclaimer:** This data sheet provides typical information and values. The properties of the final product can be influenced by casting parameters, section size, and heat treatment cycles. For critical design and procurement, the complete and latest version of the **ASTM A608** specification must be consulted. -:- For detailed product information, please contact sales. -: Cast Stainless Steel HK30, ASTM A608 Specification Dimensions Size： Diameter 20-1000 mm Length <4215 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 HK30, ASTM A608 Properties -:- For detailed product information, please contact sales. -:

Applications of Cast Stainless Steel Seamless tube HK30, ASTM A608 -:- For detailed product information, please contact sales. -: Chemical Identifiers Cast Stainless Steel Seamless tube HK30, ASTM A608 -:- For detailed product information, please contact sales. -:

Packing of Cast Stainless Steel Seamless tube HK30, 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 686 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