AISI 1144 Steel, annealed

AISI 1144 Steel, annealed at 790°C (1450°F) Product Information -:- For detailed product information, please contact sales. -: AISI 1144 Steel, annealed at 790°C (1450°F) Synonyms -:- For detailed product information, please contact sales. -:

AISI 1144 Steel, annealed at 790°C (1450°F) Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: AISI 1144 Steel, Annealed at 790°C (1450°F)** **Overview** AISI 1144 steel in the **annealed at 790°C (1450°F)** condition is a thermally processed material optimized for maximum machinability and formability. Annealing is a critical heat treatment that involves heating the steel to a temperature above its recrystallization point and then cooling it slowly to produce a soft, ductile microstructure with minimal residual stress. For AISI 1144, annealing at 790°C (1450°F) followed by controlled cooling (typically furnace cooling) transforms the as-rolled or cold-worked structure into a state with the lowest possible hardness, the highest ductility, and excellent dimensional stability. This condition is specifically engineered as the optimal starting point for complex machining operations, severe cold forming, or as a uniform precursor for subsequent heat treatment processes. **Key Features & Advantages** * **Optimal Machinability:** Produces the softest possible condition for AISI 1144, significantly reducing cutting forces, minimizing tool wear, and enabling high-speed machining with superior surface finish. The free-machining sulfur inclusions remain effective in this soft matrix. * **Maximum Ductility and Formability:** Achieves the highest elongation and reduction of area values for this grade, making it suitable for demanding cold-forming operations (such as bending or coining) after machining. * **Complete Stress Relief and Homogeneity:** Eliminates all residual stresses from prior rolling or cold working, ensuring exceptional dimensional stability during machining and preventing warping or distortion in finished parts. * **Uniform Microstructure:** Creates a consistent, coarse pearlitic-ferritic structure (often with spheroidized carbides) that ensures predictable and repeatable machining behavior and uniform response to further processing. * **Ideal Pre-Condition for Hardening:** Provides a uniform, stress-free, and soft starting condition ideal for subsequent through-hardening (quenching and tempering) or surface hardening processes, ensuring minimal distortion and consistent results. --- **1. Chemical Composition (Standard Conformance)** The chemical composition remains the defining characteristic of the AISI 1144 grade. | Element | Standard Range (%) | Key Function | | :--- | :--- | :--- | | **Carbon (C)** | 0.40 – 0.48 | Provides base strength potential. In the annealed state, carbon exists as soft pearlite or spheroidized carbides. | | **Manganese (Mn)** | 1.35 – 1.65 | Enhances hardenability potential and combines with sulfur to form MnS inclusions. | | **Phosphorus (P)** | 0.04 – 0.09 | Solid solution strengthens ferrite; contributes to the "stress-proof" characteristic in the cold-worked state. | | **Sulfur (S)** | 0.24 – 0.33 | **Primary free-machining additive.** Forms soft, globular manganese sulfide (MnS) inclusions that act as chip breakers. | | **Silicon (Si)** | 0.15 – 0.35 | Deoxidizer and solid solution strengthener. | | **Iron (Fe)** | Balance | Base element. | **Key International Standard Equivalents:** * **UNS:** G11440 * **ASTM:** A29 (Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought and Cold-Finished) - Annealed condition can be specified. * **SAE:** J403, J412 (SAE 1144) * **Common Brand Names:** "Stressproof"® refers to cold-drawn material; annealed 1144 is a standard heat-treated mill condition. --- **2. Typical Physical & Mechanical Properties (Annealed at 790°C / 1450°F)** *Note: These properties represent the softest achievable state for AISI 1144, obtained via full annealing with slow cooling.* | Property | Typical Value / Description | | :--- | :--- | | **Density** | 7.85 g/cm³ (0.284 lb/in³) | | **Modulus of Elasticity** | 200 - 210 GPa (29,000 – 30,500 ksi) | | **Machinability (Comparison)** | **~85-90%** (Based on 100% for AISI 1212) – **Excellent.** This is the most machinable condition for this grade. | | **Tensile Strength** | 520 – 620 MPa (75 – 90 ksi) | | **Yield Strength (0.2% Offset)** | 310 – 415 MPa (45 – 60 ksi) | | **Elongation (in 50mm)** | 25% – 35% | | **Reduction of Area** | 50% – 65% | | **Brinell Hardness (HB)** | 149 – 187 | | **Microstructure** | Coarse lamellar pearlite and ferrite, or spheroidized cementite in a ferrite matrix, with globular MnS inclusions. | | **Dimensional Stability** | Excellent, due to complete stress relief. | | **Surface Condition** | Uniform annealing oxide scale, typically removed by pickling or shot blasting. | --- **3. Product Applications** AISI 1144 in the annealed condition is specified for applications where extreme machinability, complex part geometry, severe cold forming, or a pre-hardening state are critical. * **Complex, High-Volume Machined Parts:** Intricate components, complex gears, and parts with deep drilling or thin walls produced on multi-axis CNC machines and Swiss-style screw machines, where maximum tool life and minimal cutting forces are essential. * **Parts for Severe Cold Forming:** Components that require significant cold bending, forging, or thread rolling after initial machining; the high ductility prevents cracking. * **Precision Blanks for Heat Treatment:** Parts that must be machined to very tight tolerances in their soft state before being through-hardened (quenched & tempered) or case hardened. The stable, annealed state minimizes distortion during the final hardening process. * **Prototyping and Tooling:** Ideal for machining prototypes, complex fixtures, jigs, and molds where easy machinability is the primary concern over final strength. * **General Parts Requiring Extensive Machining:** Where a large volume of material must be removed; the soft state reduces power consumption and improves cycle times. --- **4. Heat Treatment Process & Considerations** * **Annealing Process:** The steel is heated to **790°C (1450°F)**, held at temperature to achieve full austenitization and carbon dissolution, and then **slowly cooled inside the furnace** at a controlled rate (often < 28°C/50°F per hour through the critical range). This slow cooling allows for the formation of the softest, most stable microstructure. * **Purpose:** To achieve minimum hardness, maximum ductility, complete stress relief, and a uniform microstructure for optimal machinability and formability. * **Comparison to Other Conditions:** * **vs. As-Rolled/Normalized:** Softer, more ductile, completely stress-relieved, and with much better machinability, but with significantly lower strength. * **vs. Cold Drawn ("Stressproof"):** Softer, more formable, and stress-free, but lacks the high strength, superior surface finish, and dimensional accuracy of cold-drawn material. * **vs. Spheroidize Annealed:** The 790°C anneal may produce a partially spheroidized structure. A dedicated spheroidize anneal (at a lower temperature, e.g., 690°C) would yield even better formability but lower machinability. * **Post-Processing:** After annealing, the scale is removed via pickling or blasting. The material is ready for immediate machining or forming. -:- For detailed product information, please contact sales. -: AISI 1144 Steel, annealed at 790°C (1450°F) Specification Dimensions Size： Diameter 20-1000 mm Length <4999 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 1144 Steel, annealed at 790°C (1450°F) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 1144 Steel, annealed at 790°C (1450°F) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 1144 Steel, annealed at 790°C (1450°F) -:- For detailed product information, please contact sales. -:

Packing of AISI 1144 Steel, 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 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 1470 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