Stainless Steel EU EN X3CrNiMo13-4 1.4313 Round Bars

Product Description

EN 1.4313 (X3CrNiMo13-4), also known as F6NM, is a low-carbon martensitic stainless steel alloyed with nickel and molybdenum. It is specifically designed for applications requiring high toughness, excellent fatigue resistance, and good weldabilitya properties that are typically difficult to achieve in standard martensitic grades like 410 or 420.

It is widely regarded as the premier material for hydroelectric turbines and high-pressure pump components.

Technical Profile: EN 1.4313 / 1.4313

Chemical Composition (%)

The addition of Nickel improves toughness and low-temperature impact strength, while Molybdenum enhances pitting corrosion resistance.

Mechanical Properties (Condition QT 780)

1.4313 is generally supplied in the Quenched and Tempered (QT) condition. The low carbon content ensures that while the steel is strong, it remains significantly tougher than higher-carbon stainless steels.

• Tensile Strength ($R_m$): 780 a 980 MPa

• Yield Strength ($R_{p0.2}$): $\ge 620$ MPa

• Elongation ($A_5$): $\ge 15\%$

• Hardness (Brinell): 230 a 285 HBW

• Impact Strength (Charpy V): $\ge 70$ J (at room temperature)

Key Characteristics

• Excellent Toughness: Unlike many martensitic steels that become brittle at low temperatures, 1.4313 maintains high impact resistance down to $-60A \text{C}$.

• Superior Weldability: The low carbon content ($<0.05\%$) minimizes the risk of cold cracking in the heat-affected zone (HAZ), making it one of the few martensitic grades that is considered truly weldable.

• Corrosion Resistance: Offers better resistance to cavitation and pitting than Grade 410, particularly in soft water and mildly corrosive industrial environments.

• Magnetic: The material is magnetic in all heat-treated conditions.

Common Applications

Grade 1.4313 is the "industry standard" for the power generation and oil & gas sectors:

• Hydroelectric Power: Pelton wheel buckets, Francis turbine runners, and Kaplan blades.

• Oil & Gas: Valve bodies, compressor components, and high-pressure pump shafts.

• Marine Engineering: Propeller shafting and offshore structural components.

• Chemical Industry: Parts for centrifuges and agitators.

Global Designations & Equivalents

Fabrication & Processing

• Heat Treatment:

  • Hardening: Heat to $950A \text{C} a 1050A \text{C}$ followed by air or oil quenching.

  • Tempering: Usually performed in two stages ($600A \text{C} a 650A \text{C}$ and $580A \text{C} a 620A \text{C}$) to achieve the fine-grained structure required for high toughness.

• Machinability: Due to its nickel content, it is "gummier" than standard 410. Rigid setups and sharp tooling are necessary to prevent work hardening.

• Welding: Use matching filler metals (e.g., E 410NiMo). Preheating to $100A \text{C} a 150A \text{C}$ is recommended for thick sections, followed by post-weld stress relieving or tempering to restore optimal properties.