31CRMOV9

31CrMoV9 Alloy Steel Product Overview

31CrMoV9, also known as DIN 1.8519, is a high-quality, chromium-molybdenum-vanadium nitriding alloy steel standardized under DIN EN 10085. Renowned for its high strength, excellent fatigue resistance, and superior wear resistance after nitriding, it is designed for components subjected to high stress and extreme conditions. The steel’s composition ensures excellent hardenability, with vanadium enhancing fatigue resistance and toughness. Typically supplied in the quenched and tempered condition (850–1100 MPa tensile strength) or annealed (max 248 HB), 31CrMoV9 achieves surface hardness up to 800 HV after nitriding, making it ideal for demanding engineering applications. It is produced using advanced processes like EAF+LF+VD or ESR for high purity and structural integrity.

Applications

31CrMoV9 is used in automotive, aerospace, and general mechanical engineering applications requiring high wear resistance and toughness:

Automotive:

• Gears, crankshafts, connecting rods, and camshafts.
• Steering knuckles, axles, and piston rods.

Industrial:

• Valve and gate valve components, superheated steam valves, and fittings.
• Cylinders for combustion engines and high-pressure shafts.
• Heavy-duty bushings, rods, and structural parts with medium to large cross-sections.

Other Uses:

• Machinery components like spindles, arbours, and forged shafts.
• High-performance fasteners and bolts requiring surface hardness.
• Plant construction components exposed to high wear and fatigue.

Chemical Composition

The chemical composition of 31CrMoV9 provides its strength, toughness, and nitriding properties:

• Chromium (Cr): Enhances hardenability, wear resistance, and nitriding response.
• Molybdenum (Mo): Improves strength and temper resistance.
• Vanadium (V): Refines grain structure, boosting fatigue resistance and toughness.
• Carbon (C): Provides hardness while maintaining sufficient ductility.

Supply Size

31CrMoV9 is available in various forms and sizes to meet industrial requirements:

• Round Bars:
  Diameter 16 mm to 700 mm.
• Flat Bars:
  Minimum: 10 mm thickness x 80 mm width.
  Maximum: 500 mm thickness x 2000 mm width.