EN 3487:2024

Overview

EN 3487:2024 is a European standard developed by CEN and ASD-STAN, specifying requirements for Steel X6CrNiTi18-10 (1.4541) used in aerospace applications. This steel grade is characterized by air melting and a softened delivery condition, provided in bars for machining with diameter or thickness (a or D) up to 250 mm. The tensile strength range is tightly controlled between 500 MPa and 700 MPa. This standard supersedes the previous EN 3487:2007 edition, offering updated specifications to ensure optimal performance in demanding aerospace environments.

Key Topics

• Material Specification
  Steel X6CrNiTi18-10 (1.4541), also referenced by W.nr 1.4541 and ASD-STAN designation FE-PA3601, features:

  • Chemical composition with chromium (17%-19%), nickel (9%-12%), titanium (up to 0.70%), and balanced iron content.
  • Limits on carbon, silicon, manganese, phosphorus, and sulfur to guarantee quality and machinability.

• Production and Treatment

  • Air melted for consistent purity and homogeneity.
  • Delivered in a softened condition with specific heat treatment between 1050°C and 1100°C followed by rapid or air cooling.
  • Bars are supplied as rolled, forged, or drawn forms for high precision machining.

• Mechanical Properties

  • Tensile strength (Rm) strictly between 500 MPa and 700 MPa.
  • Proof stress minimums between 210 MPa and 220 MPa depending on cross-section size.
  • Elongation minimum of 40% ensuring ductility.
  • Hardness capped at 217 HB to facilitate machining operations.

• Quality and Testing

  • Microstructure control with δ ferrite limited to 8%.
  • Inclusion content and internal imperfections classified under Category 2 and Class 2 respectively, per EN 4700-002 standards.
  • Inspection methods include visual, ultrasonic testing, marking, and dimensional checks to ensure compliance with aerospace safety and reliability standards.

• Normative References
  The standard aligns with other key aerospace metallic material documents including:

  • EN 2043 (semi-finished product qualification)
  • EN 4436 (δ ferrite content determination)
  • EN 4700-002 (technical specifications for bars and sections)

Applications

EN 3487:2024 steel bars are tailored for aerospace components requiring high-quality machinable stainless steel that combines strength, corrosion resistance, and excellent mechanical properties. Common applications involve:

• Structural aerospace parts and frameworks
• Precision-machined components subject to dynamic and fatigue stresses
• High-performance fittings and fasteners
• Components demanding strict dimensional tolerances and surface finish

The softened delivery condition facilitates machining processes, reducing tool wear and improving manufacturing efficiency. The control of impurities and microstructure ensures long-term durability and safety under harsh operational conditions typical in aerospace environments.

Related Standards

To complement EN 3487:2024 and ensure comprehensive material performance, the following standards are relevant:

• EN 4258 – Framework for aerospace materials standardization, providing organizational guidelines for metallic material specifications.
• EN 4500-005 – Rules for drafting and presenting aerospace steel standards, ensuring consistency and clarity.
• EN 2043 – Qualification requirements for semi-finished aerospace products, essential for verifying conformity before further processing.
• EN 4436 – Test methods for evaluation of δ ferrite content, critical for microstructural integrity.
• EN 4700-002 – Technical specifications for wrought steel bars and sections, defining key testing procedures and acceptance criteria.

These interconnected standards support the full lifecycle from material selection to final aerospace application compliance.

EN 3487:2024 delivers precise guidelines for high-quality stainless steel bars designed for the aerospace industry. Its focus on chemical composition, mechanical performance, and quality assurance makes it a key reference for manufacturers and engineers seeking reliable stainless steel solutions optimized for machining and structural durability in aerospace technology.