GB Standard 38CrMoAlA Steel Round Bar / Steel Shaft 80mm 100mm 120mm Diameter

Products Specification

Standard Size of our Steel Round Bar In Stock

1. Overview

38CrMoAlA is a high-performance nitriding steel widely used in precision engineering due to its exceptional surface hardness, wear resistance, and fatigue strength. This round bar is optimized for applications requiring a combination of a ultra-hard nitride layer and a tough core, making it ideal for high-stress environments.

2. Key Features

• Ultra-Hard Surface: Achieves 1000–1250 HV after gas nitriding, suitable for abrasive conditions.

• Deep Nitride Layer: Adjustable depth (0.2–0.7 mm) based on nitriding duration and temperature.

• High-Temperature Stability: Retains mechanical properties up to 500°C.

• Machinability: Pre-nitriding machinability rating of 70% (compared to free-cutting steels).

3. Technical Specifications

Chemical Composition

Dimensions & Tolerances

• Diameter Range: 15–250 mm (hot-rolled), 10–120 mm (cold-drawn).

• Length: Standard 3–6 m, custom lengths up to 12 m.

• Straightness Tolerance: ≤1.5 mm/m (cold-drawn), ≤3 mm/m (hot-rolled).

4. Performance Data

Core Mechanical Properties (Post-Quenching & Tempering)

• Tensile Strength: 950–1100 MPa

• Yield Strength: ≥800 MPa

• Elongation (δ5): ≥12%

• Impact Energy (Charpy, 20°C): ≥55 J

Nitrided Layer Properties

• Surface Hardness: 1000–1250 HV

• Case Depth: 0.3–0.6 mm (standard 50-hour nitriding).

• White Layer Control: ≤25 μm (adjustable via process parameters).

5. Processing Guidelines

Recommended Workflow

1. Soft Annealing: 850–880°C, furnace cooling to ≤220 HBW for machining.

2. Rough Machining: Pre-shape components with allowances for nitriding distortion.

3. Stress Relieving: 550–600°C post-machining to minimize dimensional changes.

4. Final Nitriding: Gas nitriding at 500–530°C for 20–100 hours.

Post-Nitriding Finishing

• Grinding or polishing to achieve surface roughness Ra ≤0.4 μm.

• Optional TiN or DLC coatings for enhanced tribological performance.

6. Industry Applications

• Power Transmission: High-load gears, spline shafts, and turbine components.

• Hydraulics: Precision piston rods, valve spools, and pump housings.

• Tooling: Extrusion dies, injection mold cores, and wear plates.

• Aerospace: Landing gear components, actuator systems.

7. Customization Options

• Surface Finish: Black oxide, shot-peened, or precision-ground.

• Certifications: EN 10204 3.1/3.2, RoHS compliance.

• Testing Services: Inclusion rating (ASTM E45), hydrogen embrittlement testing.

8. Packaging & Delivery

• Standard Packaging: Waterproof wrapping, steel strapping, and end protectors.

• Export Compliance: Packed in ISO-compliant bundles for sea/air freight.

• Lead Time: 15–30 days (stock items), 60–90 days (custom sizes).

9. Why Choose Our 38CrMoAlA Round Bars?

• Consistent Quality: Melted in electric arc furnaces with vacuum degassing for low inclusion levels.

• Technical Support: Free nitriding process optimization consulting.

• Global Supply: Warehouses in EU, Asia, and North America for fast delivery.

Contact us for tailored solutions to meet your high-performance alloy steel needs!