ASTM A736 Low Alloy Steel Seamless tube, Grade C, Class 1

ASTM A736 Low Alloy Steel Seamless tube, Grade C, Class 1 Product Information -:- For detailed product information, please contact sales. -: ASTM A736 Low Alloy Steel Seamless tube, Grade C, Class 1 Synonyms -:- For detailed product information, please contact sales. -:

ASTM A736 Low Alloy Steel, Grade C, Class 1 Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: ASTM A736 Grade C, Class 1 Low-Alloy Steel** **ASTM A736/A736M Grade C, Class 1** is a high-performance **precipitation-strengthened low-alloy steel** specifically formulated for **welded pressure vessels requiring exceptional strength and toughness in moderate to lower temperature service**. As part of the advanced A736 specification, this grade achieves its superior mechanical properties through a sophisticated **nickel-copper-chromium-molybdenum-niobium alloy system** combined with optimized **heat treatment**. Grade C offers **higher strength levels than Grade A** within the same classification system, while Class 1 represents the baseline toughness requirements for this strength category. This material is particularly valuable for applications where **weight reduction and high design pressures** are critical design considerations. --- ## **International Standard & Key Specifications** * **Primary Standard:** **ASTM A736/A736M** - Standard Specification for Pressure Veller Plates, Low-Carbon Age-Hardening Nickel-Copper-Chromium-Molybdenum-Columbium Alloy Steel. * **Grade Distinction:** **Grade C** provides **higher minimum tensile and yield strength requirements** compared to Grade A within the same classification system, while maintaining similar chemical composition ranges. * **Classification System:** **Class 1** denotes the standard toughness requirements for this strength grade, typically tested at **0°F (-18°C)**. * **ASME Code Equivalent:** **SA-736/SA-736M** in ASME Boiler and Pressure Vessel Code, Section II, Part A. Mandatory for ASME-stamped pressure equipment. * **Governing Standard:** **ASTM A20/A20M** - Standard Specification for General Requirements for Steel Plates for Pressure Vessels. --- ## **Chemical Composition (Weight %, max unless range is specified)** The chemical composition for Grade C follows the same ranges as Grade A but is produced to achieve higher mechanical properties through optimized processing and heat treatment. | Element | Composition Range (%) | Role in Performance | | :--- | :--- | :--- | | **Carbon (C)** | 0.07 max | **Ultra-low carbon** - Ensures excellent weldability and base metal toughness; enables precipitation-hardening mechanism. | | **Manganese (Mn)** | 0.40 - 0.70 | Provides solid solution strengthening and enhances hardenability. | | **Phosphorus (P)** | 0.025 max | Impurity - Kept at minimum levels to prevent embrittlement. | | **Sulfur (S)** | 0.025 max | Impurity - Tightly controlled for optimal weldability and ductility. | | **Silicon (Si)** | 0.15 - 0.50 | Deoxidizer and solid solution strengthener. | | **Nickel (Ni)** | 0.70 - 1.00 | Improves toughness and hardenability; enhances microstructural stability. | | **Chromium (Cr)** | 0.40 - 0.65 | Increases hardenability and provides moderate corrosion resistance. | | **Molybdenum (Mo)** | 0.20 - 0.30 | **Critical element** - Enhances strength, improves elevated temperature properties, and reduces temper embrittlement susceptibility. | | **Copper (Cu)** | 1.00 - 1.30 | **Primary precipitation-hardening element** - Forms coherent Cu-rich precipitates during aging/tempering. | | **Columbium (Cb/Nb)** | 0.02 - 0.10 | **Key microalloy** - Provides grain refinement and precipitation strengthening through Nb(CN) precipitates. | | **Vanadium (V)** | 0.03 - 0.08 | Secondary precipitation strengthener. | | **Aluminum (Al)** | 0.06 max | Grain refining deoxidizer. | --- ## **Typical Physical & Mechanical Properties (Grade C, Class 1)** Properties are typically achieved through normalizing and tempering or quenching and tempering heat treatments. | Property | Value / Description | | :--- | :--- | | **Tensile Strength** | **690 - 860 MPa (100,000 - 125,000 psi)** | | **Yield Strength (min)** | **585 MPa (85,000 psi)** | | **Elongation in 2-in (50 mm) (min)** | 18% | | **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:** **0°F (-18°C)**. **Minimum Avg. for 3 Specimens:** **25 ft·lbf (34 J)**. | | **Brinell Hardness (typical)** | 220 - 280 HBW | | **Key Strength Advantage:** Provides approximately **10-15% higher minimum yield strength** than Grade A, Class 1, enabling more efficient pressure vessel designs. | --- ## **Product Applications** ASTM A736 Grade C, Class 1 is specified for high-performance pressure vessels where both strength and toughness are important, particularly in applications requiring reduced wall thickness or higher design pressures. **Primary Industries and Equipment:** 1. **Power Generation:** * **High-Pressure Feedwater Heaters** in conventional and combined-cycle power plants. * **Moisture Separator Reheaters (MSRs)** and **Steam Drums**. * **Hydrogen Coolers** and associated high-pressure vessels. 2. **Petrochemical & Refining:** * **Moderate Pressure Reactors** in chemical processing plants. * **High-Pressure Separators** and **Scrubbers** in refinery operations. * **Heat Exchanger Shells** for demanding thermal services. 3. **Gas Processing & Transportation:** * **High-Pressure Gas Storage Vessels** for natural gas and industrial gases. * **Tube Trailers and Transport Modules** for compressed gases. * **Process Vessels** in gas treatment facilities. 4. **General Heavy Industry:** * **High-Pressure Accumulators** in hydraulic systems. * **Specialized Pressure Vessels** for mining and mineral processing. --- ## **Advantages and Critical Fabrication Considerations** * **Advantages:** * **High Strength-to-Weight Ratio:** 85 ksi minimum yield strength enables significant weight reduction in pressure vessel designs. * **Good Toughness Properties:** Maintains adequate impact toughness for most industrial applications. * **Excellent Weldability:** Ultra-low carbon content minimizes welding complications despite high strength levels. * **Precipitation Hardening Capability:** Achieves high strength through controlled precipitation rather than high carbon content. * **Critical Fabrication & Welding Considerations:** * **Heat Treatment Sensitivity:** Final properties depend on precise tempering/aging parameters. Fabrication processes must not expose the material to temperatures that would over-age the microstructure. * **Welding Procedure Requirements:** **Mandatory use of low-hydrogen welding processes.** Welding consumables should be selected to match the strength and toughness of the base metal. * **Preheat and Interpass Temperature Control:** Typically **200°F - 300°F (95°C - 150°C)** depending on thickness, to prevent hydrogen-induced cracking. * **Post-Weld Heat Treatment (PWHT):** Generally required for pressure vessel fabrication. PWHT parameters must be carefully controlled to avoid over-aging. * **Thermal Cutting Considerations:** Preheating is recommended for flame cutting to prevent hardening along cut edges. * **Non-Destructive Testing:** Standard NDT requirements apply, with particular attention to weld quality given the high strength of the material. **In summary, ASTM A736 Grade C, Class 1 is a high-strength, precipitation-hardened low-alloy steel that offers an excellent balance of 85 ksi minimum yield strength and good toughness for pressure vessel applications. Its enhanced strength compared to Grade A makes it particularly suitable for designs where weight reduction and higher pressure capabilities are important considerations, while maintaining the excellent weldability characteristic of the A736 family of steels.** -:- For detailed product information, please contact sales. -: ASTM A736 Low Alloy Steel, Grade C, Class 1 Specification Dimensions Size： Diameter 20-1000 mm Length <4530 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 A736 Low Alloy Steel, Grade C, Class 1 Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A736 Low Alloy Steel Seamless tube, Grade C, Class 1 -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A736 Low Alloy Steel Seamless tube, Grade C, Class 1 -:- For detailed product information, please contact sales. -:

Packing of ASTM A736 Low Alloy Steel Seamless tube, Grade C, Class 1 -:- 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 1001 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