Hot Rolled and Forged 30CrNiMo8 Alloy Steel Round Bar in 6m Length Q+T Solid Solution

Products Specification

• High Tensile & Yield Strength: After Q+T treatment, 30CrNiMo8 typically achieves yield strengths of ≥900 MPa and tensile strengths up to 1100–1200 MPa, making it ideal for high-load components.
• Excellent Toughness & Impact Resistance: Even at sub-zero temperatures, this steel maintains ductility and resists brittle fracture—critical for safety-critical parts.
• Superior Hardenability: The synergistic effect of Cr, Ni, and Mo ensures deep and uniform hardening during quenching, minimizing distortion and cracking risks.
• Good Machinability in Annealed State: While supplied in Q+T condition for end-use performance, the steel can be pre-machined in softer states if required.
• Enhanced Fatigue & Wear Resistance: Perfect for shafts, gears, crankshafts, connecting rods, and other cyclically loaded components.
• Controlled Grain Structure: Hot rolling followed by forging refines the grain flow, improving mechanical integrity and reducing internal defects.
• Standard 6m Length: Optimized for transport efficiency and machining yield, minimizing waste during fabrication.

1. Electric Arc Furnace (EAF) Melting: High-purity raw materials melted under controlled atmosphere.
2. Ladle Refining & Vacuum Degassing: Ensures ultra-low levels of gases (H₂, O₂, N₂) and inclusions for superior cleanliness.
3. Continuous Casting or Ingot Casting: Followed by homogenization annealing to eliminate segregation.
4. Hot Rolling: Performed at precise temperatures to achieve fine-grained austenite structure.
5. Open-Die or Closed-Die Forging (Optional): For critical applications requiring directional grain flow and enhanced density.
6. Quenching & Tempering (Q+T):
   • Quenching: Rapid cooling in polymer or oil medium after austenitizing (～850–880°C).
   • Tempering: Reheated to 550–650°C to relieve stresses and develop tempered martensite microstructure.
7. Straightening, Grinding (Optional), and Ultrasonic Testing: Ensures straightness tolerance (<1.5 mm/m) and internal soundness.
8. Final Inspection & Certification: Dimensional checks, hardness verification, and chemical/mechanical testing per EN 10204.

• Diameter Range: 20 mm to 300 mm (custom sizes available)
• Standard Length: 6 meters (cut-to-length options: 3m, 4m, 6m, or customer-specific)
• Tolerance (ISO h11/h12): ±0.5% to ±1.0% of nominal diameter
• Surface Finish: Black hot-rolled scale (as-rolled) or peeled/ground upon request
• Straightness: ≤ 1.5 mm per meter

• Heavy Machinery: Axles, spindles, hydraulic rods, and transmission shafts
• Automotive & Trucking: Crankshafts, camshafts, differential gears, and steering knuckles
• Oil & Gas: Drill collars, downhole tools, and high-pressure valve stems
• Defense & Aerospace: Landing gear components, torsion bars, and armored vehicle parts
• Power Generation: Turbine shafts, generator rotors, and coupling hubs
• Industrial Equipment: High-stress fasteners, forging dies, and extrusion screws

• Germany: 30CrNiMo8 (DIN 1.6580)
• Europe: 30NiCrMo8 (EN 10083-3)
• USA: AISI 4340 (approximate; note: 30CrNiMo8 has higher Ni content)
• China: 30Cr2Ni2Mo (GB/T 3077)
• France: 30NCD11
• Japan: Not directly equivalent; closest is SNCM439

• Mill Test Certificate (EN 10204 3.1 or 3.2)
• Chemical analysis report
• Mechanical test results (tensile, impact, hardness)
• Heat treatment parameters log
• Optional: Ultrasonic testing (UT) per EN 10228-3, magnetic particle inspection (MPI)

• Bars are bundled with steel straps, protected with anti-rust oil and plastic end caps
• Seaworthy packaging for export (fumigated wooden pallets or steel cradles)
• Standard delivery time: 7–25 days depending on size and quantity
• Global shipping via sea, air, or land freight