20 Years Experience | 1000+ Brand Partners | Full Customization
We have 20 years of industry experience, have partnered with over 1,000 brands, and support any customization needs.
Technical Specifications
Product Overview
Metallurgical Characteristics
GB 40Cr is a medium carbon chromium alloy steel with excellent hardenability and strength characteristics. The chromium content (0.80-1.10%) provides enhanced hardenability, allowing for through-hardening in larger sections compared to plain carbon steels. The steel exhibits a predominantly martensitic microstructure when properly quenched, with tempered martensite after tempering operations.
Heat Treatment Process
MetalZenith employs precise heat treatment protocols for optimal properties:
- Normalizing: 860-900°C, air cooling
- Annealing: 790-820°C, furnace cooling to 500°C, then air cooling
- Quenching: 840-860°C, oil quenching
- Tempering: 550-650°C depending on required hardness
Manufacturing Process Excellence
Our integrated manufacturing process begins with carefully selected raw materials melted in advanced electric arc furnaces. Secondary refining through ladle metallurgy and vacuum degassing ensures exceptional cleanliness and chemical homogeneity. Continuous casting produces high-quality billets, which are subsequently hot-rolled or forged to final dimensions using state-of-the-art equipment.
Quality Standards and Testing
MetalZenith maintains strict adherence to international quality standards including GB/T 3077, ASTM A29, and equivalent specifications. Comprehensive testing protocols include:
- Chemical analysis using optical emission spectroscopy
- Mechanical testing per ASTM A370 and GB/T 228 standards
- Metallographic examination and grain size analysis
- Non-destructive testing including ultrasonic and magnetic particle inspection
- Dimensional verification and surface quality assessment
🧪 Chemical Composition
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.37-0.44 |
| Silicon (Si) | 0.17-0.37 |
| Manganese (Mn) | 0.50-0.80 |
| Phosphorus (P) | ≤ 0.035 |
| Sulfur (S) | ≤ 0.035 |
| Chromium (Cr) | 0.80-1.10 |
| Nickel (Ni) | ≤ 0.30 |
| Copper (Cu) | ≤ 0.25 |
| Aluminum (Al) | ≥ 0.015 |
⚙️ Mechanical Properties
| Property | Value | Condition |
|---|---|---|
| Tensile Strength | 980-1180 MPa | Quenched & Tempered |
| Yield Strength | ≥ 785 MPa | Quenched & Tempered |
| Elongation | ≥ 9% | Quenched & Tempered |
| Reduction of Area | ≥ 45% | Quenched & Tempered |
| Hardness (HB) | 293-331 | Quenched & Tempered |
| Impact Energy (KV) | ≥ 39 J | Room Temperature |
| Fatigue Limit | 450-500 MPa | 107 cycles |
| Young's Modulus | 210 GPa | Room Temperature |
🔬 Physical Properties
| Property | Value | Temperature |
|---|---|---|
| Density | 7.85 g/cm³ | 20°C |
| Melting Point | 1460-1520°C | - |
| Thermal Conductivity | 42.6 W/m·K | 20°C |
| Thermal Expansion Coefficient | 12.3×10-6/K | 20-100°C |
| Specific Heat Capacity | 460 J/kg·K | 20°C |
| Electrical Resistivity | 0.25 µΩ·m | 20°C |
| Magnetic Permeability | Ferromagnetic | 20°C |
| Curie Temperature | 770°C | - |
📏 Product Specifications
| Specification | Available Options | Standards |
|---|---|---|
| Product Forms | Round bars, square bars, flat bars, plates, sheets, tubes, forgings | GB/T 3077, ASTM A29 |
| Round Bar Diameter | 10-300 mm | GB/T 702 |
| Plate Thickness | 6-100 mm | GB/T 709 |
| Sheet Thickness | 0.5-6 mm | GB/T 708 |
| Length | 3-12 meters (custom lengths available) | Customer specification |
| Surface Finish | Hot rolled, cold drawn, peeled, ground, polished | GB/T 3077 |
| Heat Treatment | Annealed, normalized, quenched & tempered | Customer requirement |
| Dimensional Tolerance | ±0.1 to ±0.5 mm (depending on size) | GB/T 702, GB/T 709 |
Let Us Create Success for Your Project
Professional Team, Premium Products, Complete Service - Your Project Success is Our Mission
Our Advantages in Processing GB 40Cr
Advanced Electric Arc Furnace Technology
MetalZenith utilizes cutting-edge electric arc furnace technology combined with ladle refining and vacuum degassing systems to produce GB 40Cr steel with exceptional chemical homogeneity and reduced inclusion content, ensuring superior mechanical properties and reliability.
Comprehensive Quality Control Systems
Our integrated quality management system features real-time chemical analysis, automated mechanical testing, and advanced metallographic examination. Every batch undergoes rigorous testing including tensile, impact, and hardness testing to guarantee compliance with international standards.
Flexible Customization and Global Supply
MetalZenith offers extensive customization capabilities including specific chemical compositions, heat treatment conditions, and dimensional requirements. Our global distribution network ensures reliable delivery worldwide with comprehensive technical support and engineering consultation services.
YOUR TRUSTED STEEL
MANUFACTURING PARTNER
Quick Inquiry
Industries We Serve
Professional steel solutions across major industries
Qualifications & Certifications
