AISI 1078 Steel, Spheroidized Annealed and Cold Drawn,UNS G10780

AISI 1078 Steel, Spheroidized Annealed and Cold Drawn Bar (UNS G10780) Product Information -:- For detailed product information, please contact sales. -: AISI 1078 Steel, Spheroidized Annealed and Cold Drawn Bar (UNS G10780) Synonyms -:- For detailed product information, please contact sales. -:

AISI 1078 Steel, Spheroidized Annealed and Cold Drawn Bar (UNS G10780) Product Information -:- For detailed product information, please contact sales. -: ### **Product Data Sheet: AISI 1078 Steel, Spheroidized Annealed & Cold Drawn Bar (UNS G10780)** #### **1. Overview** AISI 1078 (UNS G10780) in the **Spheroidized Annealed and Cold Drawn** condition represents a premium, process-ready form of this high-carbon steel. This specialized thermomechanical treatment transforms the material into an ideal feedstock for **severe cold forming** and **precision machining**. The spheroidized anneal produces the softest, most ductile state possible for a steel of this carbon content, while the subsequent cold drawing enhances dimensional accuracy, surface finish, and provides a controlled increase in strength. This product is engineered for manufacturers who must perform complex shaping at room temperature before imparting the final, extreme hardness and strength through heat treatment. --- #### **2. Chemical Composition (AISI/SAE Standard)** The high carbon content defines its ultimate performance potential. | Element | Content (%) | | :--- | :--- | | **Carbon (C)** | **0.72 - 0.85** | | **Manganese (Mn)** | 0.60 - 0.90 | | **Phosphorus (P)** | ≤ 0.040 | | **Sulfur (S)** | ≤ 0.050 | | **Silicon (Si)** | 0.15 - 0.35 | | **Iron (Fe)** | Balance | **Note:** This identical composition to standard AISI 1078 ensures the same exceptional hardenability in the final part. --- #### **3. Typical Physical & Mechanical Properties (As-Delivered Condition)** *Properties reflect the unique soft, uniform microstructure optimized for forming.* | Property | Typical Value / Description | | :--- | :--- | | **Condition** | Spheroidized Annealed + Cold Drawn | | **Microstructure** | **Spheroidite** (Globular carbides in a soft ferrite matrix) | | **Tensile Strength** | 520 - 655 MPa (75 - 95 ksi) | | **Yield Strength (0.2% Offset)** | **415 - 585 MPa (60 - 85 ksi)** *(Enhanced by cold work)* | | **Elongation (in 50 mm)** | **≥ 15%** | | **Reduction in Area** | **≥ 50%** | | **Hardness** | **75 - 90 HRB** (Rockwell B) / **137 - 190 HB** (Brinell) | | **Machinability** | **Good for its carbon level (~65% of AISI 1212).** The spheroidized structure allows for better chip breaking, lower tool wear, and improved surface finish compared to a pearlitic structure. | | **Cold Formability** | **Excellent.** This is the primary purpose of this condition. It can withstand severe deformation (high reduction cold heading, extrusion, bending) without cracking. | | **Surface Finish & Tolerance** | Smooth, bright, scale-free surface. Tighter dimensional tolerances and superior straightness compared to hot-rolled products. | | **Hardenability Potential** | **Unchanged – Excellent.** After final part forming, it can be quenched and tempered to achieve **60-65 HRC**. | --- #### **4. Key Characteristics & Metallurgical Rationale** * **Spheroidized Anneal:** This prolonged heat treatment converts the hard, lamellar pearlitic cementite into soft, spherical carbides. This drastically reduces hardness and internal stress, maximizing ductility and toughness in the pre-form state. * **Cold Drawing Benefits:** After annealing, the bar is drawn through a die. This process: * Improves dimensional accuracy and consistency. * Provides a superior surface finish. * Imparts slight strain hardening, increasing yield strength. * Enhances straightness. * **Dual-Phase Fabrication Advantage:** The material is supplied in a **soft phase** for easy fabrication and then transformed by the manufacturer into a **hard phase** for end-use performance. * **Controlled Response:** This condition ensures uniform, predictable behavior during cold forming and a consistent response to subsequent hardening. --- #### **5. Primary Product Applications** This product form is the specified starting material for high-volume manufacturing of critical, high-strength components via cold forming processes. * **Cold Headed & Upset Fasteners:** **High-grade bolts, screws, rivets, and pins** for automotive, aerospace, and heavy machinery where severe head forming or shank reduction is required. * **Cold Forged Components:** Complex parts like **automotive transmission shafts, gear blanks, and tool bodies** formed by cold extrusion or forging. * **Springs (Cold Coiled):** Wire for the manufacture of **high-stress compression and torsion springs** via cold coiling processes. * **Precision Machined Parts:** Components such as **blanks for cutting tools, firearm parts, or precision shafts** that require extensive machining prior to hardening. * **Bearings & Pins:** For parts that are machined to tight tolerances in the soft state and then case hardened or through-hardened. --- #### **6. Relevant International & Industry Standards** This specific condition meets stringent requirements for cold-forming quality steels. | Standard System | Standard Designation | Title / Scope (Relevant to this Product Form) | | :--- | :--- | :--- | | **AISI / SAE / UNS (USA)** | **1078, SAE J403, UNS G10780** | Standard Grade Designation | | **ASTM (USA)** | **ASTM A1074** | **Key Standard:** Specification for Hot-Rolled and Spheroidized Annealed Steel Bars for Forging and Similar Applications. | | **ASTM (USA)** | **ASTM A29/A29M** | Specification for Steel Bars, Carbon and Alloy. Spheroidize annealing is an optional requirement. | | **ASTM (USA)** | **ASTM A510** | Specification for General Requirements for Wire Rods and Coarse Round Wire. | | **DIN / EN (Germany/EU)** | **1.1231 / C75W2 (+C)** | EN 10263-4: Steel rod, bars and wire for cold heading and cold extrusion. The "+C" denotes a spheroidized annealed condition. | | **JIS (Japan)** | **SWRCH77A / SWRCH77B** | Carbon steel wires for cold heading (JIS G3507-1). Often supplied annealed. | | **GB (China)** | **ML75 / ML80** | Cold Heading and Cold Extruding Steel (GB/T 6478). | --- ### **Processing Pathway & Critical Notes** 1. **Fabrication:** The component is **cold headed, cold forged, extruded, or precision machined** from the soft, spheroidized bar. 2. **Stress Relieving (Optional but Recommended):** After severe cold work, a low-temperature stress relief (~300-400°C / 575-750°F) may be used to prevent delayed cracking before hardening. 3. **Heat Treatment (Final Step):** * **Austenitize:** ~790-815°C (1450-1500°F). * **Quench:** Typically in oil for uniformity and to minimize distortion/cracking. * **Temper:** Immediately to desired hardness (e.g., 200-450°C / 400-840°F). 4. **Finishing:** Any final grinding or surface treatment. **Weldability:** Remains **very poor**. Any welding must be completed before the final quench and temper, with strict pre/post-heat protocols. **Summary:** AISI 1078 Spheroidized Annealed & Cold Drawn Bar is a high-performance engineering material designed for **manufacturing efficiency**. It enables the production of complex, high-strength components through room-temperature forming processes, dramatically reducing machining time and cost. Its value lies in its ability to be easily shaped before being transformed into an extremely hard and durable final product, making it indispensable for the fastener, automotive, and precision tooling industries. -:- For detailed product information, please contact sales. -: AISI 1078 Steel, Spheroidized Annealed and Cold Drawn Bar (UNS G10780) Specification Dimensions Size： Diameter 20-1000 mm Length <4870 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 1078 Steel, Spheroidized Annealed and Cold Drawn Bar (UNS G10780) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 1078 Steel, Spheroidized Annealed and Cold Drawn Bar (UNS G10780) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 1078 Steel, Spheroidized Annealed and Cold Drawn Bar (UNS G10780) -:- For detailed product information, please contact sales. -:

Packing of AISI 1078 Steel, Spheroidized Annealed and Cold Drawn Bar (UNS G10780) -:- 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 1341 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