AISI 86B50 Steel, annealed

AISI 86B50 Steel, annealed Product Information -:- For detailed product information, please contact sales. -: AISI 86B50 Steel, annealed Synonyms -:- For detailed product information, please contact sales. -:

AISI 86B50 Steel, annealed Product Information -:- For detailed product information, please contact sales. -: **Product Overview: AISI 86B50 Steel (Annealed Condition)** This document provides a comprehensive technical introduction to AISI 86B50 alloy steel supplied in the **annealed** condition. This state represents the softest and most machinable form of the steel, achieved through a controlled heat treatment process to relieve stresses and produce a uniform, coarse microstructure ideal for extensive machining prior to final hardening. **1. International Standard Designations** * **AISI/SAE (USA):** 86B50 (The "B" indicates the addition of Boron for enhanced hardenability) * **ASTM (USA):** A304 (Standard Specification for Carbon and Alloy Steel Bars Subject to End-Quench Hardenability Requirements) * **UNS:** G86600 * **Common Delivery Specification:** ASTM A29/A29M (General Requirements for Steel Bars) in the annealed condition. * **Note:** This is a boron-treated variant. The closest non-boron equivalent is AISI 8650, but hardenability differs significantly. * **Similar/Equivalent Standards:** Direct, standardized international equivalents are less common due to the specific boron addition, but it is functionally similar to medium-carbon, boron-treated alloy steels in other systems (e.g., certain **DIN** specifications like 38B2, but with added Ni and Cr). **2. Chemical Composition (Weight %)** The composition is similar to 86xx series steels, with the critical addition of Boron (~0.0005-0.003%) to dramatically increase hardenability without requiring large amounts of other alloying elements. | Element | Content (%) | Primary Function | | :--- | :--- | :--- | | **Carbon (C)** | 0.48 - 0.53 | Provides core hardness and strength potential. | | **Manganese (Mn)** | 0.75 - 1.00 | Increases strength and hardenability. | | **Silicon (Si)** | 0.15 - 0.35 | Deoxidizer, increases strength. | | **Chromium (Cr)** | 0.40 - 0.60 | Increases hardenability and wear resistance. | | **Nickel (Ni)** | 0.40 - 0.70 | Enhances toughness and hardenability. | | **Molybdenum (Mo)** | 0.15 - 0.25 | Promotes deep hardening and temper resistance. | | **Boron (B)** | 0.0005 - 0.003 | **Powerful hardenability enhancer**, allows for leaner overall alloy design. | | **Phosphorus (P)** | ≤ 0.025 | Impurity, kept low for toughness. | | **Sulfur (S)** | ≤ 0.025 | Impurity, affects machinability. | | **Iron (Fe)** | Balance | - | **3. Heat Treatment: Annealing** * **Process:** The steel is heated above its upper critical temperature (typically in the range of **830-860°C / 1525-1580°F**), held to fully austenitize, and then **cooled very slowly** in the furnace. This results in a coarse, soft pearlitic and ferritic microstructure. * **Purpose:** To produce the **lowest possible hardness and maximum ductility**. This relieves all internal stresses from prior rolling or forging, improves dimensional stability, and optimizes the material for heavy or complex machining operations. **4. Resulting Physical & Mechanical Properties (Typical for Annealed Condition)** *Important: Properties listed are for the annealed, pre-machining state only. Final service properties are achieved after quenching and tempering.* * **Microstructure:** Coarse lamellar pearlite in a ferrite matrix. * **Tensile Strength:** 550 - 700 MPa (80,000 - 102,000 psi) * **Yield Strength (0.2% Offset):** 350 - 500 MPa (51,000 - 73,000 psi) * **Elongation (in 50mm):** ≥ 20% * **Reduction of Area:** ≥ 55% * **Hardness:** 170 - 210 HBW (Approx. 85 - 95 HRB) * **Machinability:** **Excellent** for an alloy steel of this strength potential, due to the soft, uniform annealed structure. **Physical Properties (Approximate at 20°C):** * **Density:** 7.85 g/cm³ * **Modulus of Elasticity:** 205 GPa (29,700 ksi) * **Poisson's Ratio:** 0.29 * **Thermal Conductivity:** ~42.0 W/m·K * **Coefficient of Thermal Expansion:** 12.3 x 10⁻⁶/K (20-100°C) **5. Product Advantages in the Annealed Condition** * **Superior Machinability:** Offers the best possible cutting conditions for this grade, minimizing tool wear and allowing for high material removal rates, complex geometries, and excellent surface finishes. * **Stress-Free State:** Ideal for parts requiring precision machining where stress-induced distortion must be minimized. * **Uniform Consistency:** Predictable and homogeneous response to cutting tools. * **Cost-Effective Fabrication:** Reduces overall manufacturing costs by enabling faster machining before the final, value-adding heat treatment. * **High Hardenability Potential:** The boron addition ensures excellent through-hardening response in subsequent heat treatment, even in moderately large sections, making it suitable for a wide range of part sizes. **6. Typical Applications (As-Supplied Annealed)** Annealed 86B50 is primarily used as **machine bar stock** for components that will be fully machined and then heat-treated by the manufacturer. Common end-uses include: * **Complex, High-Strength Gears and Pinions** (for automotive, truck, and industrial transmissions) * **Heavy-Duty Shafts, Axles, and Spindles** * **Forging Dies and Tooling Blanks** * **Critical Fasteners and Bolting** (e.g., for high-pressure applications) * **Components for Agricultural and Construction Machinery** * **Parts requiring deep case hardening** (after machining, it can be carburized or carbonitrided). **7. Available Form & Supply** * **Form:** Typically supplied as hot-rolled or cold-drawn **Round Bars**, also available in other sections (squares, flats). * **Condition:** Supplied in the **Fully Annealed** condition as per ASTM A29. * **Surface:** Black (as-annealed), descaled, or sometimes turned. * **Sizes:** Wide range of diameters available as machine bar stock. **Disclaimer:** The annealed condition is a pre-machining, pre-hardening state. All performance properties (wear resistance, fatigue strength, etc.) are developed after final quenching and tempering. The boron addition makes this grade particularly sensitive to proper heat treatment cycles. Specifications and hardenability data should be confirmed with the material supplier against relevant standards (e.g., ASTM A304). -:- For detailed product information, please contact sales. -: AISI 86B50 Steel, annealed Specification Dimensions Size： Diameter 20-1000 mm Length <6375 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 86B50 Steel, annealed Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 86B50 Steel, annealed -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 86B50 Steel, annealed -:- For detailed product information, please contact sales. -:

Packing of AISI 86B50 Steel, annealed -:- 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 2846 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