EN 4472:2007

Overview

EN 4472:2007 is a European standard developed by CEN that specifies the technical requirements for aerospace-grade steel FE-PM1505 (X1CrNiMoAlTi12-9-2). This premium steel grade is characterized by its vacuum induction melting and consumable electrode remelting processes, combined with solution and precipitation heat treatments. The standard focuses on forgings with a thickness or diameter (a or D) up to 150 mm and guarantees a minimum tensile strength (Rm) of 1,400 MPa.

This standard is specifically intended for the aerospace sector, ensuring that materials meet stringent durability, strength, and performance criteria for critical aerospace components.

Key Topics

Steel Grade and Composition

• Material: Steel FE-PM1505 (X1CrNiMoAlTi12-9-2)
• Chemical composition limits: Chromium (Cr) ~11.5-12.5%, Molybdenum (Mo) ~1.85-2.15%, Nickel (Ni) ~8.5-9.5%, Aluminum (Al) ~0.6-0.8%, Titanium (Ti) ~0.28-0.37%, with minimal carbon, silicon, and manganese content.
• The steel is nitrogen-controlled and derived from vacuum induction melting followed by consumable electrode remelting, enhancing purity and mechanical properties.

Manufacturing Process

• Forgings: The standard applies to forged products manufactured from approved forging stock.
• Melting method: Vacuum induction melting and consumable electrode remelting to ensure high-quality microstructure.
• Heat treatment: Includes solution treatment at temperatures between 820 °C and 860 °C, followed by precipitation treatment (aging) at 510 °C to 530 °C for a minimum of 4 hours to achieve required mechanical properties.

Mechanical Properties

• Tensile strength (Rm): Minimum 1,400 MPa for aerospace applications.
• Proof stress (Rp0.2): ≥ 1,300 MPa.
• Elongation (A): ≥ 8-9% depending on test direction.
• Reduction of area (Z): ≥ 40-50%.
• Hardness: Between 363 HB (Brinell hardness) maximum in softened conditions to ≥ 400 HB in precipitation-treated condition.
• Impact strength: Minimum 30-40 Joules with notch sensitivity.

Dimensions and Testing

• Applicable to forgings with thickness or diameter (a or D) ≤ 150 mm.
• Test directions include longitudinal (L) and transverse (T), with the option to test either direction depending on forging size.
• Strict control of grain size, internal and external defects, batch uniformity, dimensional and marking inspections according to related aerospace standards and test protocols.
• Compliance with related standards for product qualification and acceptance testing.

Applications

EN 4472:2007 steel FE-PM1505 is engineered for critical aerospace components that require exceptional mechanical strength, corrosion resistance, and reliability. Typical aerospace applications include:

• Structural forgings and components for aircraft engines and airframes.
• High-performance mechanical parts where fatigue resistance and toughness are vital.
• Components subjected to high temperature and stress conditions, such as turbine disks and landing gear parts.
• Aerospace assemblies requiring material consistency, traceability and compliance with international aerospace quality standards.

Related Standards

EN 4472:2007 is part of a wider series of aerospace metallic material standards coordinated under EN 4258. Key related standards include:

• EN 4258: General organization of aerospace metallic material standards.
• EN 4346: Steel FE-PM1505 in softened forging stock condition up to 300 mm diameter or thickness.
• EN 4500-5: Rules for drafting and presenting aerospace metallic material standards, including specific rules for steels.
• EN 4700-6: Technical specification for aerospace steel and heat-resistant alloy forgings, covering pre-production and production processes.

These standards collectively ensure that aerospace manufacturers and suppliers maintain consistent quality, mechanical properties, and traceability for critical aerospace components.

Keywords: EN 4472:2007, steel FE-PM1505, aerospace steel forgings, vacuum induction melting, consumable electrode remelting, solution treatment, precipitation treatment, aerospace materials standard, high strength steel, tensile strength 1400 MPa, aerospace forgings, European aerospace standards.