ASTM A844 Alloy Steel Capillary

ASTM A844 Alloy Steel Capillary Product Information -:- For detailed product information, please contact sales. -: ASTM A844 Alloy Steel Capillary Synonyms -:- For detailed product information, please contact sales. -:

ASTM A844 Alloy Steel Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: ASTM A844 Alloy Steel** **ASTM A844** is a specialized **9% nickel alloy steel** specifically engineered for **cryogenic applications at extremely low temperatures down to -320°F (-196°C)**. This steel is supplied in the **normalized and tempered or double normalized and tempered condition**, which develops a fine-grained microstructure with exceptional low-temperature toughness. The material's primary application is in **liquid natural gas (LNG) storage and transportation systems**, where it provides reliable containment with excellent fracture resistance at cryogenic temperatures. ASTM A844 offers a more cost-effective alternative to austenitic stainless steels for many cryogenic applications while maintaining superior strength. --- ## **International Standard & Key Specifications** * **Primary Standard:** **ASTM A844/A844M** - Standard Specification for Steel Plates, 9% Nickel Alloy, for Pressure Vessels, Produced by the Normalized and Tempered or Double Normalized and Tempered Method. * **Key Distinction:** This specification specifically covers **9% nickel steel produced by normalized and tempered processes**, distinguishing it from ASTM A553 which covers quenched and tempered 9% nickel steel. * **ASME Code Equivalent:** **SA-844/SA-844M** in ASME Boiler and Pressure Vessel Code, Section II, Part A. Mandatory for ASME-stamped cryogenic pressure equipment. * **Governing Standard:** **ASTM A20/A20M** - Standard Specification for General Requirements for Steel Plates for Pressure Vessels. * **Related Specification:** **ASTM A553 Type I** (9% nickel steel, quenched and tempered) is the alternative heat treatment route for similar applications. --- ## **Chemical Composition (Weight %, max unless range is specified)** The composition is precisely controlled with nickel as the primary alloying element, balanced with carbon for strength and other elements for processing control. | Element | Composition (%) | Role in Performance | | :--- | :--- | :--- | | **Carbon (C)** | 0.13 max | Kept very low to maximize weldability and toughness at cryogenic temperatures. | | **Manganese (Mn)** | 0.90 max | Provides solid solution strengthening while maintaining good toughness. | | **Phosphorus (P)** | 0.035 max | Impurity, kept at minimum levels for optimal toughness. | | **Sulfur (S)** | 0.035 max | Impurity, controlled for weldability and ductility. | | **Silicon (Si)** | 0.15 - 0.40 | Deoxidizer and solid solution strengthener. | | **Nickel (Ni)** | **8.50 - 9.50** | **Critical alloying element.** Lowers the ductile-to-brittle transition temperature dramatically, enabling exceptional toughness at cryogenic temperatures. | | **Chromium (Cr)** | 0.25 max | Residual element, limited to avoid excessive hardenability. | | **Molybdenum (Mo)** | 0.12 max | Residual element. | | **Copper (Cu)** | 0.35 max | Residual element. | | **Vanadium (V)** | 0.03 max | May be present in trace amounts. | **Note:** The high nickel content (9%) is the defining feature that enables the steel's exceptional cryogenic toughness through stabilization of austenite and refinement of the microstructure. --- ## **Typical Physical & Mechanical Properties** Properties are for normalized and tempered or double normalized and tempered plates. | Property | Value / Description | | :--- | :--- | | **Tensile Strength** | 690 - 825 MPa (100,000 - 120,000 psi) | | **Yield Strength (min)** | **585 MPa (85,000 psi)** | | **Elongation in 2-in (50 mm) (min)** | 20% | | **Reduction of Area (min)** | 45% | | **Modulus of Elasticity** | ~200 GPa (29 x 10⁶ psi) | | **Density** | ~7.85 g/cm³ (0.284 lb/in³) | | **Charpy V-Notch Impact Toughness** | **Test Temperature:** **-320°F (-196°C)**. **Minimum Avg. for 3 Specimens:** **25 ft·lbf (34 J)**. **Minimum Single Value:** 20 ft·lbf (27 J). | | **Maximum Allowable Stress (ASME Sec. VIII Div. 1)** | Significantly higher than austenitic stainless steels at cryogenic temperatures. | | **Brinell Hardness (typical)** | 220 - 280 HBW | | **Thermal Conductivity** | Higher than austenitic stainless steels, beneficial for heat transfer in cryogenic applications. | --- ## **Product Applications** ASTM A844 is specifically designed for cryogenic pressure vessel applications, particularly in the LNG industry and other ultra-low temperature processes. **Primary Industries and Equipment:** 1. **LNG Infrastructure:** * **Storage Tanks** for liquefied natural gas (both aboveground and in-ground). * **Transportation Vessels** including LNG carriers, tanker trucks, and rail cars. * **Process Equipment** in LNG liquefaction and regasification plants. 2. **Industrial Gas Production:** * **Storage Vessels** for liquid oxygen, nitrogen, and argon. * **Cryogenic Process Vessels** in air separation units. * **Transportation Dewars** for industrial gases. 3. **Chemical Processing:** * **Reactors and Separators** for low-temperature chemical processes. * **Ethylene and Propylene Storage** and processing equipment. 4. **Specialized Applications:** * **Superconducting Magnet Containment** systems. * **Space and Research Applications** requiring cryogenic containment. * **Components** in hydrogen energy infrastructure. --- ## **Advantages and Critical Fabrication Considerations** * **Advantages:** * **Exceptional Cryogenic Toughness:** Guaranteed impact properties at -320°F (-196°C) make it suitable for the most demanding cryogenic applications. * **High Strength:** 85 ksi minimum yield strength provides excellent strength-to-weight ratio. * **Cost-Effective Alternative:** More economical than austenitic stainless steels for many cryogenic applications while offering higher strength. * **Good Thermal Conductivity:** Better heat transfer properties than stainless steels, beneficial for temperature management. * **Critical Fabrication & Welding Considerations:** * **Specialized Welding Requirements:** **Must be welded with nickel-alloy filler metals** (AWS A5.11 ENiCrMo-6, A5.14 ERNiCrMo-3/4). Carbon steel or stainless steel fillers are not suitable. * **Stringent Preheat Control:** Preheat typically **150-250°F (65-120°C)** is required, but must be carefully controlled to avoid excessive heat input. * **Post-Weld Heat Treatment (PWHT):** **Generally required** for pressure vessel fabrication. PWHT temperature must be below the original tempering temperature (typically 1050-1150°F / 565-620°C) to avoid overtempering. * **Welding Procedure Qualification:** WPS must be rigorously qualified with impact testing of weld metal and HAZ at the design temperature (-320°F/-196°C). * **Thermal Cutting:** Preheating is required for flame cutting. Plasma or laser cutting is preferred for critical edges. * **Ferromagnetic Property:** Unlike austenitic stainless steels, 9% nickel steel is ferromagnetic, which must be considered for certain applications. * **Thermal Expansion:** Coefficient of thermal expansion is lower than austenitic stainless steels but higher than carbon steels, affecting thermal stress calculations. * **Comprehensive NDT:** Requires 100% radiographic (RT) and ultrasonic testing (UT) of all welds in critical cryogenic service. **In summary, ASTM A844 is a premium 9% nickel alloy steel specifically engineered for cryogenic service down to -320°F. Its normalized and tempered heat treatment provides an excellent combination of high strength and exceptional low-temperature toughness, making it the material of choice for LNG storage and transportation, industrial gas equipment, and other critical cryogenic applications where reliability at extreme temperatures is paramount.** -:- For detailed product information, please contact sales. -: ASTM A844 Alloy Steel Specification Dimensions Size： Diameter 20-1000 mm Length <4548 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 A844 Alloy Steel Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A844 Alloy Steel Capillary -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A844 Alloy Steel Capillary -:- For detailed product information, please contact sales. -:

Packing of ASTM A844 Alloy Steel Capillary -:- 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 Capillary 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 1019 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