34CrNiMo6 (1.6582) Alloy Steel Properties

34CrNiMo6 Alloy Steel, also known under the material number 1.6582, is a high-performance quenched and tempered alloy steel. It is widely used for components requiring high tensile strength, good toughness, and resistance to fatigue. At Aobo Steel, we leverage our 20+ years of forging expertise to supply top-quality 34CrNiMo6 for demanding engineering applications.

1.  34CrNiMo6 Alloy Steel Chemical Composition: EN 10263-4:2017 (1.6582)

• Carbon (C): 0.30−0.38% – Provides hardness and strength.
• Silicon (Si):≤0.30%
• Manganese (Mn): 0.50−0.80% – Improves hardenability and strength.
• Phosphorus (P): ≤0.025% – Impurity, maintained at a low level.
• Sulfur (S): ≤0.025% – Impurity, kept low.
• Chromium (Cr): 1.30−1.70% – Increases hardenability, wear resistance, and strength.
• Nickel (Ni): 1.30−1.70% – Enhances toughness and hardenability.
• Molybdenum (Mo): 0.15−0.30% – Improves hardenability, high-temperature strength, and resistance to temper embrittlement.

Note: Compositions according to other standards, such as GB/T 3077 and ISO 683-2, are very similar, ensuring consistency across specifications.

2. 34CrNiMo6 Alloy Steel Heat Treatment

To achieve its optimal properties, 34CrNiMo6 requires precise heat treatment:

• Quenching: Typically performed after heating to an austenitizing temperature of 830−860°C, followed by quenching in oil. This process creates a hard martensitic structure.
• Tempering: Conducted after quenching, usually within the range of 540−680°C. Tempering reduces hardness slightly but significantly improves toughness. The final hardness (e.g., approx. 248 HBW) depends directly on the selected tempering temperature.

Aobo Steel possesses in-depth knowledge of heat treatment processes, which are critical for achieving the required material specifications.

3. Mechanical Properties of 34CrNiMo6 Alloy Steel

Understanding the mechanical properties of 34CrNiMo6 (also known as material number 1.6582) is essential for selecting the right steel for demanding applications. At Aobo Steel, with our extensive experience in tool and alloy steels, we know that heat treatment is critical to unlocking the full potential of this material. This page outlines the key mechanical properties you can expect from 34CrNiMo6.

3.1 Properties in the Annealed Condition

When supplied in the annealed condition, 34CrNiMo6 steel typically has a maximum hardness of 241 HBW. This softer state is primarily intended to facilitate easier machining before the final heat treatment process.

3.2 Properties After Quenching and Tempering (Q&T)

For most structural and high-stress applications, the mechanical properties achieved after quenching and tempering are the most important consideration. These treatments develop the necessary high strength, toughness, and fatigue resistance. The specific properties achieved depend significantly on the component’s section size and the precise tempering temperature used.

Below are the typical minimum or range mechanical properties for 34CrNiMo6 after quenching and tempering, according to standard specifications, varying by diameter or thickness (t):

Sections (t)	Tensile Strength (Rm)	Yield Strength (ReL)	Elongation (A)	Reduction of Area (Z)	Impact Toughness (KV)
t ≤ 16 mm	1200-1400 MPa	≥ 1000 MPa	≥ 9%	≥ 40%	≥ 35 J
16 mm < t ≤ 40 mm	1100-1300 MPa	≥ 900 MPa	≥ 10%	≥ 45%	≥ 45 J
40 mm < t ≤ 100 mm	1100-1200 MPa	≥ 800 MPa	≥ 11%	≥ 50%	≥ 45 J

3.3 The Role of Tempering

It is essential to recognize that these values are achieved through precise heat treatment. Tempering, performed after quenching, allows for fine-tuning the final properties. Generally, higher tempering temperatures reduce hardness and strength but increase ductility and impact toughness. Selecting the appropriate tempering process is key to meeting the specific demands of the final component.

4. 34CrNiMo6 Alloy Steel Applications

These properties make 34CrNiMo6 suitable for highly stressed components across various industries, including:

• Automotive crankshafts, steering components, and connecting rods.
• Aerospace landing gear components.
• Oil and Gas drilling tools.
• General engineering shafts, gears, tool holders, and high-strength fasteners.

While its composition allows for surface hardening techniques, 34CrNiMo6 is most commonly used in the through-hardened (quenched and tempered) condition to leverage its excellent core strength and toughness for heavy-duty applications.

5. Equivalent Grades