31CrMoV9 1.8509 / 38CrMoAlA Nitriding Alloy Steel Round Bar For Precision Machining Length 6m Diameter 10-300mm

31CrMoV9(1.8509)/ 38CrMoAlA Nitriding Alloy Steel Round Bar for Precision Machining

Products Specification

Product Name: 38CrMoAlA Alloy Steel Round Bar (Nitriding Steel)

• Standard: GB/T 3077 (China)
• Material Type: High-Strength Nitriding Alloy Steel
• Shape: Round Bar (Diameter Range: Φ10mm–Φ300mm, customizable)

Chemical Composition (wt%):

Mechanical Properties (After Heat Treatment):

• Tensile Strength (σ₃): ≥980 MPa

• Yield Strength (σ₅): ≥835 MPa

• Elongation (δ): ≥14%

• Impact Toughness (AKU): ≥63 J

• Surface Hardness (After Nitriding): ≥850 HV

Key Features:

1. Excellent Nitridability: High aluminum (Al) content ensures a hard, wear-resistant nitride layer (0.3–0.5mm depth).

2. High Core Strength: Suitable for heavy-load components requiring both surface hardness and core toughness.

3. Stability: Good resistance to tempering and fatigue.

Heat Treatment Recommendations:

• Quenching: 930–950°C (Oil cooling)

• Tempering: 600–650°C (Air cooling)

• Nitriding: 500–530°C (Ion/Gas nitriding for optimal surface hardness)

Typical Applications:

• Precision gears, shafts, and spindles

• Injection molding machine screws

• Aerospace and automotive high-wear components

• Hydraulic/pneumatic cylinders

Equivalent Grades (International Standards):

• USA (ASTM/AMS): AMS 6470 (Nitraloy 135M)

• Europe (EN/DIN): 31CrMoV9 (1.8509)

• Japan (JIS): SACM645

Packaging & Delivery:

• Packaging: Bundles with steel straps, waterproof paper, or as per customer request.

• Surface Protection: Oiled or phosphated to prevent rust.

• Lead Time: 15–30 days (Subject to quantity).

Certifications:

• Mill Test Certificate (MTC) per EN 10204 3.1

• Compliance with GB, ISO, or customer-specified standards.

Note: Custom sizes, heat treatment, and testing (e.g., UT, hardness mapping) are available upon request.