AISI 1144 Steel, normalized

AISI 1144 Steel, normalized at 900°C (1650°F) Product Information -:- For detailed product information, please contact sales. -: AISI 1144 Steel, normalized at 900°C (1650°F) Synonyms -:- For detailed product information, please contact sales. -:

AISI 1144 Steel, normalized at 900°C (1650°F) Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: AISI 1144 Steel, Normalized at 900°C (1650°F)** **Overview** AISI 1144 is a high-strength, medium-carbon "stress-proof" free-machining steel. When supplied in the **normalized at 900°C (1650°F)** condition, it undergoes a critical thermal process that refines its grain structure, homogenizes the microstructure, and enhances mechanical consistency. This heat treatment involves heating the steel uniformly into the austenite phase region and then cooling in still air. For AISI 1144, normalization provides a more uniform and balanced set of properties compared to the as-rolled state, improving toughness, dimensional stability for machining, and creating an ideal, predictable starting condition for further processing or final use. **Key Features & Advantages** * **Refined & Homogeneous Microstructure:** Eliminates the coarse, non-uniform grain structure from hot rolling, resulting in a finer, more consistent mixture of ferrite and pearlite. This enhances overall toughness and reduces property variation. * **Optimized Mechanical Property Balance:** Delivers a more favorable and predictable combination of strength, hardness, and ductility than the as-rolled condition. It typically offers slightly lower strength but significantly improved toughness and uniformity. * **Improved Machinability Consistency:** The uniform, stress-relieved structure provides more consistent chip formation and cutting forces during machining compared to the variable as-rolled condition. * **Stress Relief & Enhanced Stability:** Effectively relieves internal stresses from rolling, minimizing the risk of distortion during subsequent machining operations. * **Superior Preparation for Further Processing:** Creates an excellent, uniform starting condition for subsequent heat treatments like through-hardening (quench & temper) or surface hardening (flame/induction), ensuring a predictable response. --- **1. Chemical Composition (Standard Conformance)** The chemical composition, which defines its "stress-proof" nature, remains unchanged. | Element | Standard Range (%) | Key Function | | :--- | :--- | :--- | | **Carbon (C)** | 0.40 – 0.48 | Provides high core strength and hardenability. | | **Manganese (Mn)** | 1.35 – 1.65 | Enhances hardenability and strength, and combines with sulfur. | | **Phosphorus (P)** | 0.04 – 0.09 | Solid solution strengthens the ferrite matrix, contributing to high yield strength. | | **Sulfur (S)** | 0.24 – 0.33 | Primary free-machining additive; forms abundant MnS inclusions. | | **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) - Normalized condition can be specified. * **SAE:** J403, J412 (SAE 1144) * **Common Brand Names:** "Stressproof"® is typically associated with cold drawn products; normalized 1144 is a standard mill heat-treated condition. --- **2. Typical Physical & Mechanical Properties (Normalized at 900°C / 1650°F)** *Note: Properties are typical for normalized condition. Exact values depend on section size due to air-cooling rate variations.* | 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)** | **~78-83%** (Based on 100% for AISI 1212) – **Good to Very Good.** More consistent than as-rolled. | | **Tensile Strength** | 620 – 760 MPa (90 – 110 ksi) | | **Yield Strength (0.2% Offset)** | **415 – 550 MPa (60 – 80 ksi)** *(Note: This is typically lower than as-rolled due to stress relief and grain refinement)* | | **Elongation (in 50mm)** | 18% – 25% *(Improved over as-rolled)* | | **Reduction of Area** | 45% – 60% | | **Brinell Hardness (HB)** | 187 – 229 | | **Impact Toughness** | Significantly improved over the as-rolled condition due to grain refinement. | | **Microstructure** | Fine, uniform lamellar pearlite in a ferrite matrix. | | **Surface Condition** | Uniform bluish-gray oxide scale from heat treatment, typically removed by shot blasting or pickling. | --- **3. Product Applications** AISI 1144 in the normalized condition is specified for components that require a more reliable, uniform, and tougher set of properties than the as-rolled state provides. * **Forged Part Blanks:** An ideal starting condition for parts that will be hot-forged, as the fine grain structure improves forgeability and leads to better final forged properties. * **Components for Subsequent Hardening:** Excellent substrate for parts like heavy-duty shafts, gears, and wear plates that will later undergo through-hardening (quench & temper) or surface hardening. The uniform structure ensures even transformation and minimizes distortion. * **General Machinery Parts Requiring Consistency:** Axles, spindles, and pins where a balanced combination of strength, toughness, and predictable machinability is more critical than maximum as-rolled strength. * **Tooling and Fixture Bases:** For jigs and fixtures requiring better stability and impact resistance than provided by annealed material. * **Agricultural and Implement Parts:** Components subject to impact loads where improved toughness from normalization is beneficial. --- **4. Heat Treatment Process & Considerations** * **Normalization Process:** The steel is uniformly heated to **900°C (1650°F)**, held for sufficient time (approx. 1 hour per inch of thickness) to achieve complete austenitization and homogeneity. It is then removed from the furnace and cooled in **still air**. * **Purpose:** Grain refinement, microstructure homogenization, stress relief, and improvement of toughness. * **Section Size Effect:** The cooling rate in still air depends on bar diameter. Smaller diameters cool faster, resulting in slightly higher strength and hardness. * **Comparison to As-Rolled:** Lower yield strength but significantly better ductility, toughness, and property uniformity. It is a more engineered and predictable condition. * **Not for Direct Use as "Stressproof":** The normalization process relieves the stresses that contribute to the "stress-proof" characteristic in the cold worked condition. Therefore, normalized 1144 does not exhibit the same high yield strength as cold drawn 1144 ("Stressproof"®). It is chosen for different performance reasons. -:- For detailed product information, please contact sales. -: AISI 1144 Steel, normalized at 900°C (1650°F) Specification Dimensions Size： Diameter 20-1000 mm Length <4998 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, normalized at 900°C (1650°F) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 1144 Steel, normalized at 900°C (1650°F) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 1144 Steel, normalized at 900°C (1650°F) -:- For detailed product information, please contact sales. -:

Packing of AISI 1144 Steel, normalized at 900°C (1650°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 1469 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