AISI 1137 Steel Seamless tube,

AISI 1137 Steel Seamless tube, annealed at 790°C (1450°F) Product Information -:- For detailed product information, please contact sales. -: AISI 1137 Steel Seamless tube, annealed at 790°C (1450°F) Synonyms -:- For detailed product information, please contact sales. -:

AISI 1137 Steel, annealed at 790°C (1450°F) Product Information -:- For detailed product information, please contact sales. -: ## **Product Data Sheet: AISI 1137 Steel, Annealed at 790°C (1450°F)** --- ### **1. Product Overview** **AISI 1137 Steel, Annealed at 790°C (1450°F)**, represents a thermally softened condition of this medium-carbon, resulfurized free-machining steel. Annealing involves heating the steel to a temperature above its recrystallization point but below the lower critical temperature (A₁), holding for sufficient time, and then cooling slowly (typically furnace cooling). This 790°C (1450°F) treatment is a **subcritical or process annealing** designed to relieve internal stresses, restore maximum ductility, and soften the material to its most machinable state without causing a full austenitic transformation. This condition is engineered to maximize **cold workability and machinability** for complex forming operations or heavy machining prior to a final hardening process. It represents the softest and most ductile standard condition in which AISI 1137 is supplied, optimizing the material for ease of manufacturing rather than final service strength. **Key Advantages of Annealed AISI 1137:** * **Maximum Softness & Ductility:** Achieves the lowest possible hardness and highest elongation, making it ideal for severe cold forming, bending, and drawing operations with minimal risk of cracking. * **Optimized Machinability:** The softened, spheroidized structure allows for reduced cutting forces, excellent chip formation, extended tool life, and superior surface finishes in complex machining operations. * **Complete Stress Relief:** Effectively eliminates nearly all internal stresses from prior cold working, hot rolling, or machining, providing a dimensionally stable and predictable material for precision manufacturing. * **Uniform Microstructure:** Produces a homogeneous distribution of fine, spheroidized carbides in a ferrite matrix, ensuring consistent mechanical behavior throughout the workpiece. --- ### **2. Chemical Composition (Standard % by Weight)** The composition remains the standard AISI 1137 specification, with its characteristic sulfur addition for machinability. | Element | Content (%) | Function & Implication in Annealing | | :--- | :--- | :--- | | **Carbon (C)** | 0.32 - 0.39 | Forms cementite (Fe₃C) carbides that spheroidize during the anneal, contributing to softness and machinability. | | **Manganese (Mn)** | 1.35 - 1.65 | In solid solution, provides some solid solution strengthening. During subcritical annealing, it slows carbide coalescence, promoting a fine, uniform spheroidized structure. | | **Phosphorus (P)** | ≤ 0.040 | Residual, kept low to prevent cold shortness (embrittlement). | | **Sulfur (S)** | 0.08 - 0.13 | **Machinability Enhancer.** Forms manganese sulfide (MnS) inclusions that improve chip breaking. Their morphology is stable during annealing. | | **Iron (Fe)** | Balance | Base metal. | --- ### **3. Typical Physical & Mechanical Properties (Annealed at 790°C / 1450°F)** *Properties reflect the maximally softened state. The cooling rate (furnace cool vs. controlled cool) significantly influences final hardness.* | Property | Typical Value (Metric) | Typical Value (Imperial) | Notes | | :--- | :--- | :--- | :--- | | **Tensile Strength** | 480 - 580 MPa | 70,000 - 84,000 psi | Minimum strength condition for this grade. | | **Yield Strength (0.2% Offset)** | 275 - 380 MPa | 40,000 - 55,000 psi | Very low yield point, easy to deform. | | **Elongation (in 50 mm)** | 25% - 35% | 25% - 35% | Maximum ductility. | | **Reduction of Area** | 55% - 70% | 55% - 70% | Excellent formability indicator. | | **Hardness** | 149 - 187 HB | 149 - 187 HB | Softest standard condition for AISI 1137. | | **Microstructure** | **Ferrite matrix with fine, spheroidized carbides.** | | Ideal for cold work and machining. | | **Machinability** | **Excellent** | | Softer structure allows for easier cutting; excellent chip control due to MnS. | --- ### **4. International Standards & Specifications** Annealing is a standard thermal processing condition applied to material conforming to base specifications. | Standard System | Grade Designation | Applicable Base Specification | Heat Treatment Note | | :--- | :--- | :--- | :--- | | **ASTM / AISI (USA)** | AISI 1137 | ASTM A29 / ASTM A108 | Can be supplied annealed per ASTM A29 or as a special requirement (often "Softened" or "Annealed"). | | **SAE (USA)** | SAE 1137 | SAE J403, J412 | - | | **UNS (USA)** | G11370 | - | - | | **DIN (Germany)** | 1.0735 (40S20) | DIN EN 10277 | Can be supplied to "**+A**" condition (Annealed) or "**+SR**" (Softened). | | **EN (Europe)** | 40S20 (1.0735) | EN 10277 | - | | **Common Callout** | **Annealed 790°C (1450°F), Furnace Cool** | | Specified for maximum formability and machinability. | --- ### **5. Primary Applications** This annealed condition is selected for components that require extensive cold deformation or heavy machining before a final heat treatment. * **Cold Heading & Extrusion:** Primary feedstock for manufacturing bolts, nuts, rivets, and complex cold-formed parts where maximum ductility is required to prevent cracking during high-strain forming. * **Complex Machined Parts:** Components with intricate geometries, deep cavities, or extensive material removal; the annealed state reduces power consumption, minimizes tool wear, and improves surface finish. * **Pre-Forms for Heat Treatment:** Blanks that are first machined or formed in this soft condition and then subsequently quenched & tempered or case hardened to achieve final properties. * **Cold Drawing & Wire:** Used as a starting material for producing cold-drawn wire, rods, and special profiles. * **General Fabrication Parts:** Brackets, spacers, and non-critical components that may be bent or formed and where the annealed softness is sufficient for the application. --- ### **6. Processing & Fabrication Notes** * **Subsequent Heat Treatment:** **Essential for most functional applications.** This annealed state is a precursor. Parts are typically **quenched & tempered** or **case hardened** after forming/machining to develop required strength and wear resistance. The uniform, soft structure allows for predictable transformation during hardening. * **Machinability:** **Excellent.** Produces a smooth finish with excellent chip control due to the combined effect of softness and MnS inclusions. Use sharp tools with polished rake faces. Cutting speeds can be higher than for normalized or as-rolled states. * **Cold Working:** **Excellent.** This is the primary reason for this treatment. It can withstand severe bending, stamping, drawing, and rolling operations with minimal risk of fracture. * **Weldability:** **Poor.** The sulfur content makes it prone to hot cracking. Welding is not recommended. If absolutely necessary, the annealed microstructure will be destroyed in the heat-affected zone, requiring post-weld heat treatment. * **Strain Hardening:** Significant cold work will rapidly increase its strength and hardness (work hardening), reducing further ductility. Intermediate annealing may be required for multi-stage forming operations. --- ### **7. Special Considerations** 1. **Spheroidization:** The 790°C anneal promotes spheroidization of carbides, which is optimal for machinability and cold forming but provides the lowest strength. For a slightly stronger but still machinable condition, consider **normalizing**. 2. **Cooling Rate:** Slow furnace cooling is essential to achieve the softest possible condition. Accelerated cooling may result in higher hardness. 3. **Anisotropy:** Even in the annealed state, the material will exhibit some anisotropy in ductility and impact properties due to the alignment of MnS inclusions. --- **Disclaimer:** The information provided is for general reference. The exact annealing cycle (temperature, time, cooling rate) can be tailored to achieve specific hardness ranges. For critical forming operations, consultation with the material supplier and heat treater is recommended. Always review full material certifications and Safety Data Sheets (SDS) prior to use. -:- For detailed product information, please contact sales. -: AISI 1137 Steel, annealed at 790°C (1450°F) Specification Dimensions Size： Diameter 20-1000 mm Length <4973 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. -: AISI 1137 Steel, annealed at 790°C (1450°F) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 1137 Steel Seamless tube, annealed at 790°C (1450°F) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 1137 Steel Seamless tube, annealed at 790°C (1450°F) -:- For detailed product information, please contact sales. -:

Packing of AISI 1137 Steel Seamless tube, annealed at 790°C (1450°F) -:- 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 1444 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