X50MnCrV20-14 Cr-Mn-N Steel Round Rods

Product Description

X50MnCrV20-14 (frequently associated with Werkstoffnummer 1.3817 or related trade names like P900V) is a premium, high-carbon Chromium-Manganese-Vanadium austenitic steel.

Unlike the previously discussed low-carbon non-magnetic grades, X50MnCrV20-14 incorporates a significantly higher carbon content ($\sim 0.50\%$) combined with Vanadium micro-alloying. This specific chemistry creates a matrix capable of achieving extreme tensile strength and superior wear resistance through strain-hardening, while maintaining a completely non-magnetic profile.

Chemical Composition (Typical Weight %)

The high carbon and manganese content ensures a stable austenitic structure, while vanadium is introduced to form hard, finely dispersed vanadium carbides ($VC$) that restrict grain growth and increase wear resistance.

• Carbon (C): High content serves as a potent interstitial strengthener and combines with Vanadium to form wear-resistant carbides.

• Manganese (Mn): Replaces nickel entirely to stabilize the austenite phase under all thermal and mechanical conditions.

• Chromium (Cr): Provides baseline corrosion resistance and contributes to carbide formation.

• Vanadium (V): Forms highly stable micro-carbides that block dislocation movement, drastically raising the yield point during cold work.

Mechanical & Physical Properties

This grade is specifically engineered to be cold-expanded or strain-hardened during manufacturing, driving its mechanical properties to levels unattainable by standard stainless steels.

Mechanical Properties (Varies by Cold-Work Level)

• Yield Strength ($R_{p0.2}$): $\ge 450\text{ MPa}$ (Solution Annealed) | Up to $1100 - 1300\text{ MPa}$ (Cold-Expanded/Strained)

• Tensile Strength ($R_m$): $850 - 1050\text{ MPa}$ (Base) | Up to $1200 - 1450\text{ MPa}$ (Work-Hardened)

• Elongation ($A_5$): $\ge 25\%$ (Even at ultra-high strength levels, it retains remarkable plasticity against catastrophic energy bursts)

• Impact Energy (KV): $\ge 50\text{ J}$ at room temperature.

Physical Characteristics

• Magnetic Permeability ($\mu_r$): $\le 1.005\text{ H/m}$ (Absolute non-magnetic reliability; no deformation-induced martensite formation).

• Density: $7.75\text{ g/cm}^3$

Standards & Cross-References

• DIN / EN Designation: X50MnCrV20-14

• Material Number (WNr): 1.3817

• Classification: Specialized Non-Magnetic Structural Steel / Generator Component Steel.

• Industry Analogs: Belongs to the high-strength Amsler or P900 series modifications tailored for elevated wear and fatigue environments.

Core Applications for Round Rods

Because X50MnCrV20-14 can handle extreme rotational and centrifugal forces without generating a magnetic signature, round rods of this material are highly valued in heavy rotational power generation and high-stress military sectors:

• High-Stress Generator Retaining Rings: Used in large-scale turbogenerators to bind rotor windings against massive centrifugal forces while remaining immune to magnetic stray-loss heating.

• Non-Magnetic heavy Duty Fasteners: Used for manufacturing specialized, high-tensile structural bolts, tie-rods, and clamping studs in naval radar masts and submarine hulls.

• Oilfield Exploration Components: High-load internals for MWD (Measurement While Drilling) tools, downhole mud motors, and logging equipment operating under intense abrasion and mechanical fatigue.

• Military Electronics Enclosures & Shafts: Structural driving components positioned adjacent to sensitive magnetic mine-detection arrays or guidance systems.

Fabrication, Machining & Heat Treatment

• Machinability: Due to the combination of high carbon, vanadium carbides, and an intense work-hardening rate, X50MnCrV20-14 is exceptionally difficult to machine. It requires rigid, heavy-duty machine tools, low surface cutting speeds, high positive feed rates, and specialized coated carbide (or ceramic) tooling to prevent immediate tool glazing.

• Heat Treatment: This grade cannot be hardened by conventional quenching and tempering. It is typically solution-annealed at $1020^\circ\text{C} - 1080^\circ\text{C}$ followed by rapid water quenching to dissolve coarse precipitates. High yield thresholds are achieved exclusively via mechanical strain hardening (e.g., cold drawing or hydraulic expansion).

• Welding: Generally not recommended for high-stress applications. The high carbon content introduces a severe risk of heat-affected zone (HAZ) carbide precipitation, which drastically lowers toughness and ruins the uniform non-magnetic stability unless a full solution anneal is performed post-weld.