34CrNiMo6 Forging Steel

Overview of 34CrNiMo6 Forging Steel

34CrNiMo6 is a high-strength, medium-carbon nickel-chromium-molybdenum alloy forging steel specified under EN 10083-3 with material number 1.6582. Engineered to provide an excellent combination of high tensile strength, superior toughness, and outstanding hardenability in large cross-sections, it is the preferred material for highly stressed components. The balanced alloy composition, typically featuring 0.34% carbon, 1.5% chromium, 1.5% nickel, and 0.2% molybdenum, ensures deep through-hardening and uniform mechanical properties even in heavy forgings.

As a heat-treatable engineering steel, 34CrNiMo6 in the quenched and tempered (Q+T) condition achieves tensile strengths ranging from 900 to 1400 MPa, depending on section size, with exceptional fatigue strength and wear resistance. This grade delivers significantly better toughness and hardenability than standard Cr-Mo steels like 42CrMo4/4140, making it ideal for critical applications where high dynamic loads and operational safety are paramount. Typical supply forms include forged round bars, forged blocks, and seamless rolled rings, manufactured through precisely controlled open-die and closed-die forging processes.

Key Features and Forging Manufacturing

34CrNiMo6 forging steel is manufactured from carefully selected scrap and ferroalloys using electric arc furnace (EAF) melting, followed by ladle refining and vacuum degassing (VD) to achieve high cleanliness and low hydrogen content. Electroslag remelting (ESR) is an option for the most demanding applications. The cast ingots or continuous cast blooms are hot forged at temperatures of 1100-1200°C using hydraulic presses or hammers, with a mandatory forging reduction ratio of at least 4:1 to eliminate the as-cast structure and guarantee isotropic mechanical properties.

Post-forging heat treatment includes normalizing, soft annealing for machinability, or a full quenching and tempering (Q+T) process. Austinitizing is performed at 830-860°C followed by oil or polymer quenching, then tempered at suitable temperatures to meet specified mechanical properties. Non-destructive testing, particularly ultrasonic inspection (UT) per EN 10228-3 or ASTM A388, is standard for all safety-critical components. Available in diameters from 80mm to 1500mm as round bars, forged blocks up to 30 tons, and rings up to 5000mm OD, the material can be supplied with rough or finish machining to exact drawing specifications.

Main Applications of 34CrNiMo6 Forging Steel

34CrNiMo6 is extensively used in the manufacturing of heavy-duty drivetrain components including transmission shafts, pinion shafts, and gear rims for industrial gearboxes, mining machinery, cement mills, and rolling mills. The wind power industry relies on this grade for highly stressed rotor shafts, main shafts, and gearbox planet carriers in multi-megawatt turbines, where it provides long-term reliability under fluctuating load conditions.

The oil and gas industry employs 34CrNiMo6 for blowout preventer (BOP) forging bodies, wellhead housings, and high-pressure pump components due to its high strength and toughness in thick sections. Marine applications include propulsion shafts, rudder stocks, and steering gear components for commercial and naval vessels. Other critical applications include high-speed generator and steam turbine shafts in power plants, railway locomotive axles, forging dies and tool holders, and large industrial press columns where maximum fatigue resistance and shock-load capacity are essential. It is also a preferred material for highly stressed automotive components like heavy-duty crankshafts and connecting rods.

Why Choose Us for 34CrNiMo6 Forging Steel

Shandong Tanglu Metal Material Co., Ltd. supplies premium 34CrNiMo6 forging steel sourced from ISO 9001 and PED certified mills with extensive expertise in producing high-integrity alloy forgings. Each 34CrNiMo6 forging is supplied with an EN 10204 3.1 Mill Test Certificate as standard, covering full chemical analysis, mechanical property results (tensile, yield, elongation, impact), ultrasonic testing (UT) reports, and dimensional checks to EN 10083-3 requirements. For safety-critical components, we provide EN 10204 3.2 certification with independent third-party witness testing by SGS, BV, or LR.

We offer a comprehensive range of forged products, from 80mm to 1500mm diameter round bars and blocks up to 30 tons to seamless rings up to 5000mm OD. Custom forging-to-print services include rough machining, semi-finishing, and finish machining. With a monthly capacity of 3,000 tons of alloy steel forgings and established export logistics to over 40 countries, we serve the wind energy, marine, oil & gas, and heavy machinery sectors. We support both urgent small quantity orders and large long-term contracts, ensuring consistent quality and timely delivery.