ASTM A439 Austenitic Ductile Iron Sheet,Plate type D2

ASTM A439 Austenitic Ductile Iron Sheet/Plate type D2 Product Information -:- For detailed product information, please contact sales. -: ASTM A439 Austenitic Ductile Iron Sheet/Plate type D2 Synonyms -:- For detailed product information, please contact sales. -:

ASTM A439 Austenitic Ductile Iron type D2 Product Information -:- For detailed product information, please contact sales. -: # **Product Technical Data Sheet: ASTM A439 Austenitic Ductile Iron – Type D-2** --- ## **1. Product Overview** **ASTM A439 Type D-2 Austenitic Ductile Iron** is a **high-nickel, chromium-alloyed austenitic spheroidal graphite iron** designed for **superior corrosion resistance, exceptional heat resistance, and excellent non-magnetic properties**. Unlike standard ferritic or pearlitic ductile irons, Type D-2 possesses a **stable austenitic matrix** at all temperatures, providing outstanding performance in aggressive chemical environments, high-temperature service, and applications requiring dimensional stability and non-ferromagnetic characteristics. It is a premier engineering material for severe service conditions where standard ductile irons and many stainless steels are inadequate. --- ## **2. Governing Standards & Specifications** This alloy is formally defined by U.S. standards, with direct equivalents in international systems. * **Primary Standard:** * **ASTM A439** - *Standard Specification for Austenitic Ductile Iron Castings* * **International Equivalents:** * **ISO 2892:** *Austenitic cast irons* – Type D-2 corresponds approximately to **AUS 202** or **L-NiCuCr 15 6 2**. * **EN 13835:** *Austenitic cast irons* – Designated as **EN-JS 2029**. * **SAE J434:** May be referenced as **D5S**. * **Common Trade Names:** * **Ni-Resist® Type D-2** (A proprietary grade from SMC and other foundries) * **Key Referenced Testing Standards:** * **ASTM E8:** Tensile Testing * **ASTM E10:** Brinell Hardness * **ASTM A247:** Microstructure Evaluation * **ASTM G48:** Pitting and Crevice Corrosion Resistance Testing --- ## **3. Chemical Composition Requirements (per ASTM A439)** The composition is the foundation of its austenitic structure and corrosion resistance. | Element | Composition Range (wt.%, ASTM A439) | Functional Role & Metallurgical Rationale | | :--- | :--- | :--- | | **Carbon (C)** | 2.60 - 3.00 | Provides graphite for machinability and castability; controlled to balance strength and avoid excessive carbides. | | **Silicon (Si)** | 1.50 - 2.50 | Promotes graphitization and solid solution strengthening. | | **Nickel (Ni)** | **18.00 - 22.00** | **Primary Austenite Stabilizer.** Ensures a fully austenitic matrix from cryogenic to melting temperatures, providing ductility, toughness, and non-magnetic properties. Also enhances corrosion resistance. | | **Chromium (Cr)** | **1.75 - 2.50** | **Key for Corrosion & Heat Resistance.** Forms a protective Cr₂O₃ passive layer, significantly improving resistance to oxidizing acids, pitting, and high-temperature scaling. Strengthens the matrix. | | **Manganese (Mn)** | 0.50 - 1.50 | Promotes austenite stability and combines with sulfur. | | **Copper (Cu)** | **≤ 0.50** | May be present; intentionally low in Type D-2 to optimize specific corrosion resistance compared to higher-Cu Ni-Resist grades. | | **Magnesium (Mg)** | ≥ 0.07 (min., residual) | Ensures spheroidal graphite formation. | | **Phosphorus (P)** | ≤ 0.08 | Kept low to prevent embrittlement. | | **Sulfur (S)** | ≤ 0.03 | Kept low. | --- ## **4. Physical & Mechanical Properties** Type D-2 offers a unique combination of properties distinct from standard ductile irons. | Property | Typical Value / Range | Notes & Significance | | :--- | :--- | :--- | | **Tensile Strength, min.** | **414 MPa (60,000 psi)** | Provides good load-bearing capacity. | | **Yield Strength (0.2% offset), min.** | **207 MPa (30,000 psi)** | Moderate yield strength characteristic of stable austenites. | | **Elongation, min.** | **20%** | **Excellent ductility,** allowing it to withstand deformation and thermal stresses without cracking. | | **Hardness (Brinell, HBW)** | **140 - 190 HBW** | Relatively soft, contributing to excellent machinability and galling resistance. | | **Modulus of Elasticity** | **~110 - 125 GPa (16 - 18 x 10⁶ psi)** | **Significantly lower** than ferritic ductile irons (~170 GPa). Important for deflection calculations and thermal stress considerations. | | **Impact Resistance** | **Excellent at all temperatures.** Maintains good toughness from cryogenic temperatures up to its service limit. | | **Density** | **~7.4 g/cm³** | Slightly higher than standard ductile iron. | | **Magnetic Permeability** | **Effectively Non-Magnetic (µᵣ ~1.05 - 1.10).** A key property for electronic, marine, and scientific applications. | | **Coefficient of Thermal Expansion** | **~18 x 10⁻⁶ /°C** | **High.** Similar to austenitic stainless steels. Requires careful design for thermal cycling with dissimilar metals. | | **Thermal Conductivity** | **~12 W/m·K** | **Low.** About 1/3 that of standard ductile iron. Affects heat transfer and thermal shock resistance. | | **High-Temperature Scaling Resistance** | **Excellent up to ~870°C (1600°F).** The combined Ni-Cr content provides superior resistance to oxidation and growth in continuous service. | | **Corrosion Resistance** | **Outstanding.** Excellent resistance to:
• **Seawater & brine**
• **Alkalis**
• **Many organic acids**
• **Dilute sulfuric, phosphoric, and nitric acids**
Resists pitting and stress corrosion cracking in chlorides. | --- ## **5. Product Applications** ASTM A439 Type D-2 is specified for some of the most demanding applications across multiple industries. * **Chemical & Petrochemical Processing:** * **Pump & valve bodies** handling corrosive chemicals, caustics, and acids. * **Heat exchanger castings, reactor components, and distillation column internals.** * **Marine & Offshore:** * **Seawater pump casings, impellers, valve bodies, and fittings.** * **Propeller shaft sleeves, stern tubes, and underwater instrument housings.** (Non-magnetic property is critical for degaussed vessels). * **Power Generation:** * **Geothermal brine pump components.** * **FGD (Flue Gas Desulfurization) system parts.** * **High-Temperature Service:** * **Exhaust manifolds, turbocharger housings, and furnace fixtures** where oxidation resistance and growth resistance are needed. * **Food & Pharmaceutical Processing:** Where corrosion resistance and cleanability are paramount. * **Cryogenic Applications:** **Components for LNG handling systems** due to good toughness at low temperatures. --- ## **6. Fabrication & Processing Notes** * **Condition:** Typically supplied **as-cast**. The austenitic structure is stable and does not require heat treatment for phase transformation. **Stress-relief annealing** may be used for dimensional stability in complex castings. * **Machinability:** **Good to Very Good.** The soft, ductile austenitic matrix produces long, stringy chips. Requires sharp, positive-rake tools, adequate cooling/lubrication, and moderate speeds/feeds. * **Weldability:** **Fair to Good (with proper procedures).** Uses matching or over-alloyed Ni-Cr-Mo filler metals (e.g., ENiCrFe-2, ENiCrFe-3). Requires pre-heat (~150-260°C) and controlled interpass temperature to prevent hot cracking and microfissuring in the HAZ. Post-weld heat treatment is often recommended. * **Casting Considerations:** Higher pouring temperatures and careful gating/risering are needed due to the high Ni content and lower fluidity compared to standard ductile iron. --- ## **7. Ordering Information** **Specify:** **"Austenitic Ductile Iron Castings, ASTM A439 Type D-2 (Ni-Resist D-2 equivalent)."** **Critical Details to Provide:** * **Applicable Standard & Grade** (ASTM A439 D-2). * **Part Drawing & Specification.** * **Service Environment** (chemical media, temperature, pressure) to confirm suitability. * **Certification Requirements:** Mill Test Report (MTR) including full chemical analysis and mechanical properties. For critical corrosion applications, **corrosion test coupons** or **Huey test** (ASTM A262 Practice C) results may be requested. * **Special Requirements:** Non-magnetic certification (maximum permeability), dimensional stability requirements, or specific NDT (PT, RT). --- ## **8. Key Advantages & Limitations Summary** * **Advantages:** * **Exceptional corrosion resistance** in a wide range of media. * **Excellent heat and oxidation resistance.** * **Outstanding ductility and toughness** across a wide temperature range. * **Non-magnetic properties.** * **Good machinability and galling resistance.** * **Limitations / Design Considerations:** * **Higher material cost** due to high nickel content. * **Lower yield strength and modulus of elasticity** than standard ductile irons. * **High coefficient of thermal expansion** requires accommodation in assemblies. * **Not resistant to strong oxidizing acids** (e.g., hot concentrated nitric) or reducing acids (e.g., hydrochloric) without inhibitors. * **Graphite in the structure** can be a limiting factor in some ultra-pure or high-vacuum applications compared to solid-solution alloys like stainless steel. **ASTM A439 Type D-2 is a versatile, high-performance alloy that solves complex material selection problems involving corrosion, heat, and magnetism, making it an indispensable material in the engineer's toolkit for severe-service applications.** -:- For detailed product information, please contact sales. -: ASTM A439 Austenitic Ductile Iron type D2 Specification Dimensions Size： Diameter 20-1000 mm Length <6551 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 D2 Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A439 Austenitic Ductile Iron Sheet,Plate type D2 -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A439 Austenitic Ductile Iron Sheet,Plate type D2 -:- For detailed product information, please contact sales. -:

Packing of ASTM A439 Austenitic Ductile Iron Sheet/Plate type D2 -:- 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 3022 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