1.3816 Cr-Mn-N Steel Round Bar

Product Description

1.3816 (EN/DIN standard name X45MnCrV8-8, often associated with premium proprietary designations like BÖHLER P501) is a high-strength, non-magnetic (amagnetic) austenitic steel.

By utilizing a high concentration of manganese combined with chromium, nitrogen, and a targeted addition of Vanadium ($\text{V}$), this alloy is engineered for components that face extreme mechanical stresses and alternating fatigue loads while requiring a completely stable, non-magnetic footprint.

Chemical Composition (Mass Weight %)

The inclusion of Vanadium ($0.10–0.25\%$) acts as a powerful grain refiner and forms stable micro-carbides/nitrides, which significantly enhances wear resistance and yield strength without compromising the stability of the non-magnetic matrix.

Critical Engineering Properties

• Stable Non-Magnetism: It exhibits a magnetic permeability ($\mu$) of $\le 1.01 \text{ G/Oe}$ in the solution-annealed state. Because the austenitic structure is highly stable, it resists transformation into magnetic martensite even under severe surface impacts or localized cold deformation.

• Wear and Fatigue Resistance: The unique synergy between the interstitial nitrogen, high carbon, and vanadium alloying elements gives 1.3816 superb resistance to adhesive wear and structural surface fatigue compared to standard lower-carbon austenitic stainless steels.

• Corrosion Resistance: With roughly $8\%$ Chromium, it provides reliable protection against atmospheric rust, industrial moisture, and mild lubricants, though it is not intended for highly aggressive chemical or acidic immersion.

Mechanical Properties (At Room Temperature)

1.3816 achieves its final mechanical thresholds through specialized thermal management and controlled strain hardening:

Heat Treatment Parameters

• Hot Forging: 1120°C to 900°C (Cooling must be managed carefully to avoid localized grain-boundary network precipitates).

• Solution Annealing: 1020°C to 1080°C, followed by an immediate, rapid quench in water or rapid forced air. This locks the carbon, nitrogen, and alloying elements perfectly into the solid austenitic solution.

Machinability Notes

Due to the combination of high carbon, vanadium carbides, and rapid work-hardening characteristics, 1.3816 is classified as tough to machine.

• Avoid low feed rates that cause tool rubbing and glazing.

• Use rigid tool holders and heavy-duty, coated carbide inserts with continuous positive feeds.

• Ensure a generous flow of high-pressure cooling lubricant to evacuate chips quickly.

Primary Applications for Round Bars

1.3816 round bars are commonly specified for mechanical parts that demand heavy structural loading alongside strict non-magnetic boundaries:

• Electrical Infrastructure: Retaining rings for generators, rotor shafts, amagnetic housings, and transformer structural components.

• Military & Defense Systems: Components for naval vessel equipment, mine-sweeping hardware, and radar array structures that must remain completely transparent to magnetic detection.

• Heavy Clamping & Fasteners: High-tensile, non-magnetic assembly studs, heavy-duty J-bolts, and specialized industrial clamping hardware subjected to high dynamic vibration.

• Mechanical Engineering: Specialized guide rods, wear-resistant non-magnetic pins, and linkage bars operating near strong electromagnetic fields.