WNr 1.6546 Alloy Steel Bar 1.6546 Round Bars 1.6546 Rods

Product Description

Werkstoff-Nr. 1.6546 (commonly designated in the EN system as 40NiCrMo2-2 or NiCrMo2-2) is a high-performance, medium-carbon nickel-chromium-molybdenum low-alloy structural steel.

Unlike the case-hardening 14 220 or 15HG grades, 1.6546 is optimized for quenching and tempering (through-hardening). The deliberate combination of nickel (for impact toughness), chromium (for depth hardenability), and molybdenum (to mitigate temper brittleness) gives this steel excellent uniform tensile properties across thick cross-sections.

Global Cross-Reference & Equivalents

When specifying or substituting WNr 1.6546 round bars or rods across international standards, use these direct equivalents:

Chemical Composition (Typical wt.%)

The carbon range positions this material perfectly for thorough hardening, while the multi-alloy system achieves robust grain refinement.

• Carbon (C): 0.37% – 0.44%

• Nickel (Ni): 0.40% – 0.70%

• Chromium (Cr): 0.40% – 0.60%

• Manganese (Mn): 0.50% – 1.00%

• Molybdenum (Mo): 0.15% – 0.30%

• Silicon (Si): 0.15% – 0.40%

• Phosphorus (P): $\le$ 0.035%

• Sulfur (S): $\le$ 0.035%

Technical Specifications & Supply Conditions

1.6546 round bars and rods are primarily distributed in one of two major processing formats:

1. Common Delivery States

• Annealed (+A): Spheroidized or soft-annealed state to keep hardness low ($\le$ 250 HBW) for automated cold-sawing, machining, or cold-heading.

• Quenched and Tempered (+QT): Pre-hardened at the mill to bring out its high-strength mechanical properties directly before final processing.

2. Standard Mechanical Properties (Typical in +QT Condition)

• Tensile Strength ($R_m$): 885 – 1100 MPa

• Yield Strength ($R_e$): $\ge$ 725 MPa

• Elongation ($A_5$): $\ge$ 16% – 25% (depending on product form)

• Hardness (Post Oil-Quench): Can achieve 45–52 HRC at the surface/mid-radius depending on bar diameter.

Core Industrial Applications

Because 1.6546 maintains outstanding fatigue resistance and high structural integrity under severe torsion and bending stresses, it is a staple material in demanding mechanical applications:

• High-Strength Fasteners: Heavy-duty turbine fasteners, boiler support rods, and aerospace engine studs/bolts (frequently matching AMS aircraft specifications).

• Power & Motion Transmission: Main drive shafts, multidiameter axles, connecting rods, high-load mechanical gears, and valve stems.

• Oil & Gas / Process Plants: High-stress manifold bolts, pressure vessel components, and heavy structural hardware.