X5CrNiMoCuNb14-5 Precipitation Hardening Steel Round Bar,X5CrNiMoCuNb14-5 Rod X5CrNiMoCuNb14-5 Bars

Product Description

1. Metallurgical Design and Phase Balance

X5CrNiMoCuNb14-5 relies on a complex, low-carbon martensitic matrix that contains a minor, balanced volume of retained austenite.

• Austenite Control: The inclusion of $5.00 - 6.00\%$ Nickel stabilizes a specific percentage of austenite at room temperature. This prevents the fully hardened martensite from becoming excessively brittle, providing the alloy with its famous sub-zero impact toughness down to $-40^\circ\text{C}$.

• Intermetallic Precipitates: During the aging cycle (such as the +P850 or +P1070 treatments), sub-microscopic phases composed of Copper (Cu) and Niobium (Nb) reject out of the solid solution. This creates strong lattice strains that dramatically elevate the material's yield strength without sacrificing structural stability.

2. Manufacturing & Finishing Formats for Bars

When ordering X5CrNiMoCuNb14-5 bars, the surface finish directly impacts both your machining costs and dimensional tolerances:

• Cold Drawn / Centerless Ground Rods: Typically supplied in smaller diameters (up to $50 - 75\text{ mm}$). These bright rods offer high precision tolerances (conforming to standard EN limits like ISO h9, h10, or h11). They are ideal for direct feeding into CNC Swiss-turn machines for high-tolerance fasteners or valve internals.

• Peeled & Polished Bars: The heavy outer oxide scale from the rolling mill is mechanically peeled off. This format offers mid-tier tolerances (like ISO k11 or k12) and is perfect if you plan to do standard lathe turning or milling on the outer diameter.

• Hot Rolled / Black Forged Bars: Supplied as-rolled with a dark mill scale. Typically ordered in large diameters ($>100\text{ mm}$) where the bar will be heavily forged down or deep-hole bored into components like heavy-duty pump cylinders.

3. Direct Translation to Alternative Global Specifications

If your engineering department or material suppliers are operating outside of Europe, you can safely substitute X5CrNiMoCuNb14-5 with these international equivalent designations:

4. Key Procurement Checklist for EN 10088-3 Compliance

To ensure that an inbound shipment of X5CrNiMoCuNb14-5 bars matches your structural engineering requirements, your Material Test Report (MTR) must explicitly detail:

1. The Delivery Condition (+A, +P850, or +P1070): The raw steel name alone does not specify hardness. You must dictate whether you want it annealed (+A) for easy machining, or pre-hardened (+P) to save on post-machining heat-treatment costs.

2. Ultrasonic Inspection: For high-speed rotating equipment (like compressor shafts or pump impellers), specify ultrasonic testing to EN 10228-3 to guarantee the core of the bar is completely free of micro-voids or internal cooling cracks.

3. Grain Boundry Verification: Ensuring the Carbon is capped below $0.07\%$ and Niobium is adequately balanced ($5 \times \text{C}$ minimum) to prevent intergranular corrosion during any necessary welding phases.