ASTM A439 Austenitic Ductile Iron Rod/Bar type D5S

ASTM A439 Austenitic Ductile Iron Rod type D5S Product Information -:- For detailed product information, please contact sales. -: ASTM A439 Austenitic Ductile Iron Rod type D5S Synonyms -:- For detailed product information, please contact sales. -:

ASTM A439 Austenitic Ductile Iron type D5S Product Information -:- For detailed product information, please contact sales. -: # **Product Technical Data Sheet: ASTM A439 Austenitic Ductile Iron – Type D-5S** --- ## **1. Product Overview** **ASTM A439 Type D-5S Austenitic Ductile Iron** is a **silicon-modified, high-nickel austenitic spheroidal graphite iron** specifically engineered for **superior resistance to high-temperature oxidation, carburization, and sulfur attack**. The "S" designation signifies its **specialized composition optimized for severe thermal service**, particularly in carburizing and sulfidizing atmospheres up to 980°C (1800°F). By incorporating elevated silicon and chromium levels within the high-nickel D-5 matrix, this alloy forms exceptionally stable, self-healing oxide scales that resist penetration by carbon and sulfur, making it the premier choice for high-temperature furnace components and heat treatment fixtures where other austenitic grades would degrade rapidly. --- ## **2. Governing Standards & Specifications** Type D-5S is a specialized high-temperature variant within the ASTM A439 family. * **Primary Standard:** * **ASTM A439** - *Standard Specification for Austenitic Ductile Iron Castings* * **International & Commercial Equivalents:** * **ISO 2892:** *Austenitic cast irons* – While not a direct 1:1 match, it falls under high-silicon, high-nickel types such as **L-NiSiCr 35 5 2**. * **Common Trade Name:** **Ni-Resist® Type D-5S** (High-Temperature, Heat-Resisting Grade). * **SAE J434:** **D5S** is a recognized automotive material specification for this alloy. * **Key Referenced Testing Standards:** * **ASTM E8/E21:** Tensile Testing * **ASTM E228:** Linear Thermal Expansion Testing * **ASTM G54:** Static Oxidation Testing * **ASTM G79:** Evaluation of Susceptibility to Embrittlement of Steels and Nickel-Base Alloys --- ## **3. Chemical Composition Requirements** Type D-5S features a balanced chemistry that prioritizes high-temperature stability over room-temperature mechanical properties. | Element | Composition Range (wt.%, Typical) | Functional Role & Metallurgical Rationale | | :--- | :--- | :--- | | **Carbon (C)** | 2.40 - 2.90 | Controlled to balance graphite formation and matrix stability. Higher carbon can promote carbide formation at high temperatures. | | **Silicon (Si)** | **4.80 - 5.50** | **The Key High-Temperature Additive.** Silicon promotes the formation of a dense, adherent SiO₂ layer within the scale. This layer **dramatically improves resistance to carburization (carbon pickup) and sulfidation**, and enhances overall oxidation resistance at extreme temperatures. | | **Nickel (Ni)** | **34.00 - 36.00** | **Primary Austenite Stabilizer.** Ensures a fully austenitic matrix that remains stable and ductile at all service temperatures, preventing detrimental phase transformations. Provides the base for low thermal expansion. | | **Chromium (Cr)** | **1.75 - 2.50** | Works synergistically with silicon to form a complex, protective (Cr,Si)₂O₃ scale that is highly resistant to spallation and penetration by aggressive species. Provides solid solution strengthening. | | **Manganese (Mn)** | 0.50 - 1.50 | Austenite stabilizer. | | **Copper (Cu)** | ≤ 0.50 | Kept low, as copper can be detrimental to high-temperature properties. | | **Magnesium (Mg)** | ≥ 0.07 (min., residual) | Ensures spheroidal graphite. | | **Phosphorus (P)** | ≤ 0.08 | Kept very low to avoid low-melting eutectics. | | **Sulfur (S)** | ≤ 0.03 | Kept very low. | *Note: Exact ranges may vary slightly by foundry; the SAE J434 D5S specification is a common reference.* --- ## **4. Physical & Mechanical Properties** Type D-5S is optimized for performance at elevated temperatures, with properties that reflect this focus. | Property | Typical Value / Range | Key Characteristics & High-Temperature Performance | | :--- | :--- | :--- | | **Tensile Strength (RT)** | **450 - 550 MPa (65 - 80 ksi)** | Good room-temperature strength, enhanced by silicon solid solution strengthening. | | **Yield Strength (RT, 0.2%)** | **250 - 350 MPa (36 - 51 ksi)** | Higher than standard D-5 due to silicon strengthening. | | **Elongation (RT)** | **8 - 15%** | Moderate ductility; sufficient for handling and service but lower than non-silicon-modified grades. | | **Hardness (Brinell, HBW)** | **170 - 230 HBW** | Higher than D-5, reflecting the strengthened matrix. | | **Coefficient of Thermal Expansion (20-400°C)** | **~10.0 - 11.5 x 10⁻⁶ /°C** | **Retains the low-CTE characteristic of the D-5 family**, crucial for thermal cycling applications. Slightly higher than D-5 due to Si. | | **Maximum Recommended Service Temperature** | **980°C (1800°F) Continuous** | **Superior to D-5 (~800°C).** The Si+Cr scale allows sustained operation in oxidizing, carburizing, and sulfidizing atmospheres. | | **Oxidation & Growth Resistance** | **Outstanding.** Minimal scaling and virtually no "growth" (permanent swelling from internal oxidation of graphite) due to the highly protective scale. Weight gain in standard oxidation tests is exceptionally low. | | **Carburization Resistance** | **Excellent.** The silicon-rich scale acts as an effective barrier against carbon diffusion into the matrix, preventing embrittlement and property degradation in furnace atmospheres. | | **Sulfidation Resistance** | **Very Good.** Superior to most other cast ferrous alloys in sulfur-bearing environments. | | **Thermal Fatigue Resistance** | **Excellent.** The combination of low CTE, good high-temperature strength, and scale adherence provides excellent resistance to crack initiation under thermal cycling. | | **Impact Resistance (RT)** | **Moderate.** Adequate for fixture applications but not for high shock loads. | | **Machinability** | **Fair to Difficult.** The high silicon content creates an abrasive, work-hardening matrix. Requires carbide tooling, rigid setups, and correct parameters. | --- ## **5. Product Applications** Type D-5S is the material of choice for the most demanding high-temperature fixture and component applications. * **Heat Treatment & Industrial Furnaces (Primary Market):** * **Fixtures, baskets, trays, and grids** for carburizing, carbonitriding, and neutral hardening furnaces. * **Rotor fans, radiant tubes, and retorts** for continuous furnaces. * **Pit furnace fixtures and charge carriers.** * **Chemical & Petrochemical Processing:** * **Reformer tube hangers, catalyst support grids, and internals** for steam methane reformers and ethylene crackers. * **Power Generation:** * **Components for high-temperature heat recovery systems.** * **Automotive (Specialized):** * **High-performance turbocharger housings and exhaust manifolds** for extreme-duty applications. --- ## **6. Fabrication & Processing Notes** * **Condition:** Typically supplied **as-cast and solution annealed**. A high-temperature solution anneal (1100-1150°C) is crucial to dissolve any secondary carbides/silicides and ensure a homogeneous austenitic structure for optimal high-temperature performance and ductility. * **"Conditioning" or "Pre-oxidation" Treatment:** For the absolute best in-service performance, a controlled pre-oxidation treatment may be applied to grow a uniform, protective scale before the component enters service, minimizing initial oxidation rates. * **Casting Considerations:** High silicon content improves fluidity but increases shrinkage tendency. Requires expert foundry practice for sound castings. The alloy is reactive; basic or neutral molding aggregates are preferred. * **Machinability:** **Challenging.** Abrasive and prone to work hardening. **Carbide tooling is mandatory.** Use positive rake angles, moderate speeds, and consistent feed to avoid glazing the work surface. * **Weldability:** **Very Poor (Generally Not Recommended).** The high Si and Ni content make it extremely prone to hot cracking and fissuring in the HAZ. The HAZ will also lose its optimized high-temperature properties. **Design for casting integrity; welding should be avoided for service components.** If repair is unavoidable, it requires extremely specialized procedures and full re-solution annealing. --- ## **7. Ordering Information** **Specify:** **"Austenitic Ductile Iron Castings, ASTM A439/SAE J434 Type D-5S (Ni-Resist D-5S), Solution Annealed."** **Critical Details to Provide:** * **Applicable Standard** (e.g., SAE J434 D5S or reference to ASTM A439 D-5S composition). * **Mandatory Heat Treatment:** "Solution Annealed" is non-negotiable. * **Part Drawing & Specification.** * **Service Conditions:** Maximum temperature, atmosphere type (e.g., endothermic gas, air, sulfidizing), and thermal cycling profile. * **Certification Requirements:** MTR with full chemical analysis (confirming high Si), mechanical properties, and heat treatment records. For critical applications, **high-temperature oxidation or carburization test reports** may be required. * **Special Processing:** Specify if a **pre-oxidation treatment** is required. --- ## **8. Summary: The High-Temperature Specialist** **ASTM A439/SAE D5S represents the ultimate in high-temperature performance among the standard austenitic ductile irons. Its value proposition is clear:** * **Primary Advantage:** **Unmatched combination of low thermal expansion, exceptional resistance to oxidation/carburization/sulfidation, and microstructural stability at temperatures up to 980°C.** * **Comparison to D-5:** D-5S **sacrifices some room-temperature ductility and machinability** to gain **vastly superior high-temperature environmental resistance**. It is the choice when the service environment is aggressively hot and chemically active. * **Comparison to D-2C:** While D-2C also offers good high-temperature resistance, **D-5S provides significantly lower thermal expansion** (critical for fixtures and dimensional stability) and even better carburization resistance due to its higher silicon content. * **Economic Note:** It is a **premium material** due to its high Ni and specialized processing, justified by extended service life in critical furnace applications. **Type D-5S is not a general-purpose alloy; it is a precision-engineered solution for extending the life and reliability of components in the most punishing thermal environments found in industrial heat processing.** -:- For detailed product information, please contact sales. -: ASTM A439 Austenitic Ductile Iron type D5S Specification Dimensions Size： Diameter 20-1000 mm Length <6559 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. -: ASTM A439 Austenitic Ductile Iron type D5S Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A439 Austenitic Ductile Iron Rod type D5S -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A439 Austenitic Ductile Iron Rod type D5S -:- For detailed product information, please contact sales. -:

Packing of ASTM A439 Austenitic Ductile Iron Rod type D5S -:- 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 3030 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