Spherical ASTM A485 Steel Powder, Grade 4

ASTM A485 Steel Spherical Powder, Grade 4 Product Information -:- For detailed product information, please contact sales. -: ASTM A485 Steel Spherical Powder, Grade 4 Synonyms -:- For detailed product information, please contact sales. -: -:- For detailed product information, please contact sales. -: Spherical ASTM A485 Steel Powder, Grade 4 characteristics -:- For detailed product information, please contact sales. -: Spherical ASTM A485 Steel Powder, Grade 4 Particle Size -:- For detailed product information, please contact sales. -: -:- -:- 0-15μm ,5-25μm, 15-45μm, 15-53μm,20-63um, 45-75μm, 45-105μm, 45-150μm ,75-150μm. (Various granularities can be customized according to customer requirements) -:- For detailed product information, please contact sales. -:

Spherical ASTM A485 Steel Powder, Grade 4 Applicable processes -:- For detailed product information, please contact sales. -: Laser/electron beam additive manufacturing (SLM/EBM, 3D printing) Direct laser deposition (DLD) Used in thermal spray (TSA) Powder hot isostatic pressing (HIP) Metal injection molding (MIM) Powder metallurgy (PM) Laser cladding (LC), etc. -:- For detailed product information, please contact sales. -: Spherical ASTM A485 Steel Powder, Grade 4 Chemical Composition -:- For detailed product information, please contact sales. -: -:- For detailed product information, please contact sales. -: ASTM A485 Steel, Grade 4 Product Information -:- For detailed product information, please contact sales. -: # **Product Technical Datasheet: ASTM A485 Grade 4 Steel** ## **1. Product Overview & Classification** **ASTM A485 Grade 4** is a premium-grade, high-hardenability **Chromium-Silicon alloy spring steel** specified under the ASTM A485 standard. It represents the highest alloyed and most performance-oriented grade within the A485 spring steel series (Grades 1-4), specifically engineered for the most demanding, heavy-duty, and high-stress spring applications. Its primary design purpose is to achieve **excellent through-hardenability** in large cross-sections while delivering **superior fatigue strength, high elastic limit, and outstanding resistance to relaxation** (set) under prolonged stress and elevated temperatures. This steel is considered a **quenched and tempered through-hardening steel**. It is supplied in the soft-annealed condition for formability and requires a final full heat treatment (austenitizing, quenching, and tempering) by the spring manufacturer to achieve its world-class mechanical properties. ### **Key International Standards & Cross-References** * **Primary Governing Standard:** **ASTM A485 - Standard Specification for High Hardenability Antifriction Bearing Steel** (Covers Grades 1-4 for spring applications). * **SAE/AISI Equivalent:** **SAE 9260** (The most direct and widely recognized equivalent). * **UNS Designation:** **G52986** (Note: UNS numbers may overlap for similar grades; chemical composition is the definitive identifier). * **European Standards (EN):** Similar to **55SiCr7 (1.0904)** or **60SiCr7 (1.0961)** under EN 10089, though compositions are not identical. * **Japanese Standard (JIS):** **SUP12** is a close analogue (Si-Cr steel). * **Common Industry Name:** **"Chrome-Silicon" Spring Steel** (High-SiCr variant). ## **2. Chemical Composition (Ladle Analysis)** The composition of Grade 4 is meticulously balanced with elevated levels of key alloying elements to maximize its core performance characteristics. | Element | Composition Range (%) | Metallurgical Function & Impact | | :--- | :--- | :--- | | **Carbon (C)** | 0.56 - 0.64 | Primary strengthening element. Provides the foundation for high tensile strength and hardness after heat treatment. | | **Manganese (Mn)** | 0.75 - 1.00 | Enhances hardenability, ensuring deep and uniform hardening. Aids in strength and solid solution strengthening. | | **Silicon (Si)** | **1.80 - 2.20** | **The defining element.** Dramatically increases the elastic limit (yield strength), improves fatigue resistance, raises tempering resistance, and significantly increases resistance to decarburization during heat treatment. | | **Chromium (Cr)** | 0.60 - 0.80 | Further enhances hardenability and promotes a fine, uniform microstructure. Improves toughness and contributes to wear resistance. | | **Phosphorus (P)** | 0.025 max | Impurity. Kept at a very low level to prevent embrittlement and improve fatigue life. | | **Sulfur (S)** | 0.025 max | Impurity. Controlled for improved machinability in the annealed state, but kept low to maintain transverse ductility. | | **Residuals (Ni, Cu, etc.)** | Specified limits apply | Controlled to ensure consistent and predictable hardenability and performance. | **Key Distinguishing Feature:** The **very high Silicon content (1.80-2.20%)** is the hallmark of Grade 4, setting it apart from lower grades (Grade 3: 1.20-1.60% Si) and providing its exceptional elastic properties. ## **3. Physical & Mechanical Properties** ### **3.1 As-Supplied Condition (Annealed)** To facilitate cold coiling or hot forming of springs, the material is supplied soft. * **Hardness:** Typically **≤ 229 HB** (Brinell) or ~95 HRB. * **Microstructure:** Spheroidized annealed structure for optimal ductility and formability. * **Purpose:** This condition allows for complex shaping before the final hardening heat treatment. ### **3.2 Properties After Final Heat Treatment (Quenched & Tempered)** *Final properties are developed by the spring manufacturer. The values below are typical for properly processed material.* | Property | Typical Range | Notes / Test Standard | | :--- | :--- | :--- | | **Tensile Strength** | 1750 - 2050 MPa (255 - 300 ksi) | Achievable across a wide tempering range. | | **Yield Strength (0.2% Offset)** | 1550 - 1850 MPa (225 - 270 ksi) | Exceptionally high due to silicon's effect on raising the elastic limit. | | **Elongation (in 50mm)** | ~8 - 12% | Varies inversely with tensile strength. | | **Reduction of Area** | ~35 - 45% | Indicates good inherent toughness. | | **Hardness (Tempered Spring)** | **HRC 46 - 52** | Most common operating range for springs. Can be tempered for other hardnesses. | | **Modulus of Elasticity (E)** | ~200 GPa (29 x 10⁶ psi) | Similar to most steels. Silicon does not significantly alter E. | | **Fatigue Strength** | **Excellent** | One of its prime advantages. High Si content and cleanliness lead to very high endurance limits under cyclic loading. | | **Hardenability (Jominy)** | **Excellent** | Meets the specified hardenability bands in ASTM A485, allowing full through-hardening of large sections (e.g., bars over 25mm/1" diameter). | ### **3.3 Key Performance Characteristics** * **High Elastic Limit:** The high silicon content allows springs to operate at higher stress levels without taking a permanent set. * **Excellent Fatigue Resistance:** Combined with high surface integrity (controlled decarb) and often enhanced by shot peening, it provides extremely long service life under dynamic loads. * **Good Relaxation Resistance:** Performs well at moderately elevated temperatures (up to ~200-250°C / 400-480°F) compared to lower-alloy steels, resisting loss of load (stress relaxation). * **High Toughness:** For its strength level, it maintains good impact resistance, providing a safety margin. ## **4. Typical Product Applications** Grade 4 is reserved for the most critical and demanding spring applications where performance, reliability, and longevity are paramount, and where cost is secondary to function. * **Ultra-High-Performance Automotive Valve Springs:** For racing engines, turbocharged/supercharged engines, and high-RPM applications where extreme stress and fatigue resistance are critical. * **Heavy-Duty Suspension Coil Springs:** For mining trucks, construction equipment, armored vehicles, and other severe-service vehicles. * **Critical Industrial Springs:** In large diesel engine fuel injection systems, heavy-duty clutch springs, high-pressure valve springs for oil & gas industries, and springs in aerospace landing gear mechanisms. * **Anti-Roll Bars (Stabilizer Bars):** For high-performance vehicles and heavy commercial vehicles requiring maximum torsional strength and fatigue life. * **Springs for Safety-Critical Systems:** Where failure would be catastrophic (e.g., certain aerospace, defense, and energy applications). ## **5. Manufacturing & Processing Guidelines** * **Available Forms:** Hot-rolled or cold-drawn round bar, flat bar; hot-rolled wire rod; peeled and polished bar. * **Forming:** Springs are typically **cold coiled** (for smaller wire) or **hot wound** (for larger bar) in the soft-annealed state. * **Critical Heat Treatment Process:** 1. **Austenitizing:** ~850-870°C (1560-1600°F) in a controlled atmosphere to minimize surface decarburization. 2. **Quenching:** Rapid **oil quench**. 3. **Tempering:** Immediately temper between **400-500°C (750-930°F)** to achieve the desired hardness/strength and relieve quenching stresses. * **Secondary Operations:** **Shot peening** is almost universally applied to dramatically improve fatigue life. Protective coatings (e.g., phosphate & oil, paint, powder coat) are used for corrosion protection. ## **6. Comparison & Selection Guidance** * **vs. A485 Grade 3:** Grade 4 has significantly higher silicon (1.80-2.20% vs. 1.20-1.60%), resulting in a higher elastic limit, better relaxation resistance, and generally superior fatigue performance. * **vs. SAE 5160/EN 51CrV4 (Cr-V steels):** Grade 4 (SAE 9260) generally offers better hardenability and fatigue strength, while Cr-V steels may offer better toughness and a finer grain structure. * **vs. Oil-Tempered Wire (ASTM A401):** A401 is supplied pre-hardened for smaller diameters. A485 Grade 4 is heat-treated *after* spring forming, making it suitable for larger sections and more complex geometries where uniform properties are essential. ## **7. Conclusion** **ASTM A485 Grade 4 (SAE 9260)** is the pinnacle of conventional chromium-silicon spring steel technology. Its unique high-silicon chemistry makes it the material of choice for engineers designing springs that must operate at the very limits of stress and cycle life. While it demands precise manufacturing and heat treatment control, the resulting components offer unmatched performance for the most severe heavy-duty, high-stress, and safety-critical applications across automotive, off-highway, industrial, and aerospace sectors. Its use is justified wherever failure is not an option and maximum performance per unit weight is required. -:- For detailed product information, please contact sales. -: ASTM A485 Steel, Grade 4 Specification Dimensions Size： Diameter 20-1000 mm Length <5206 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. -: ASTM A485 Steel, Grade 4 Properties -:- For detailed product information, please contact sales. -:

Spherical ASTM A485 Steel Powder, Grade 4 Particle Size Description -:- For detailed product information, please contact sales. -: Applications of Spherical ASTM A485 Steel Powder, Grade 4 -:- For detailed product information, please contact sales. -: -:- For detailed product information, please contact sales. -: Applications of ASTM A485 Steel Spherical Powder, Grade 4 -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A485 Steel Spherical Powder, Grade 4 -:- For detailed product information, please contact sales. -:

Packing of ASTM A485 Steel Spherical Powder, Grade 4 -:- 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 Spherical Powder 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 1677 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