EN 4346:2007

Overview

EN 4346:2007 is a European standard developed by the Comité Européen de Normalisation (CEN) that specifies the technical and quality requirements for Steel FE-PM1505 (X1CrNiMoAlTi12-9-2). This steel grade is produced via vacuum induction melting and consumable electrode remelting, then softened and supplied as forging stock with dimensions a or diameter (D) ≤ 300 mm. This standard is tailored specifically for aerospace industry applications, ensuring the steel meets stringent performance, reliability, and safety criteria critical to aircraft and aerospace component manufacturing.

Key Topics

• Material Composition: The standard defines a precise chemical composition for FE-PM1505 steel, which includes chromium (Cr), molybdenum (Mo), nickel (Ni), aluminum (Al), titanium (Ti), and other trace elements. Key elements control corrosion resistance, strength, and heat treatment response.
• Melting Process: The steel is processed by vacuum induction melting combined with consumable electrode remelting. This double melting method ensures superior purity, uniform microstructure, and low inclusion content essential for aerospace parts.
• Forging Stock Requirements: The standard specifies conditions for softening treatment and forging stock form, including dimensional constraints (≤ 300 mm in diameter or thickness), ensuring consistency for downstream forging and machining.
• Heat Treatment: Detailed heat treatment guidance includes solution and precipitation treatments to optimize mechanical properties such as tensile strength, hardness, elongation, and impact resistance.
• Mechanical Properties:
  • Proof stress ≥ 1300 MPa
  • Tensile strength ≥ 1400 MPa
  • Elongation ≥ 8-9%
  • Reduction of area ≥ 40%
  • Hardness ≤ 400 HB
• Quality Controls and Testing:
  • Macrographic and microstructural examinations
  • Ultrasonic inspection for internal defects
  • Measurement of δ-ferrite content (max 2%)
  • Inclusion cleanliness classification (Category 5 micro-cleanness)
• Marking and Dimensions: Traceability through marking as per EN 2157-2 and dimensional inspections ensure conformity to aerospace manufacturing specifications.

Applications

EN 4346:2007 steel grade FE-PM1505 is primarily used in aerospace engineering for the production of high-strength, corrosion-resistant forged components where performance under extreme conditions is essential. Applications include:

• Aircraft structural parts such as landing gear components, engine mounts, and turbine blades.
• Aerospace fasteners and connectors requiring high fatigue strength and resistance to stress corrosion cracking.
• Critical forging stock for specialty aerospace alloys that undergo further machining and heat treatments.
• Any aerospace application demanding rigorous metallurgical integrity aligned with international aerospace metal standards.

Related Standards

• EN 4258 – Provides general organizational guidelines for aerospace metallic materials standardization.
• EN 2157-2 – Addresses technical specifications for forging stock including delivery conditions for steels.
• EN 4436 – Defines test methods for determining δ-ferrite content in steels.
• EN 4050-1 – Ultrasonic inspection methodology for metallic semi-products.
• EN 2043 – Sets forth general requirements for semi-finished product qualification in aerospace.
• EN 2003-7 – Covers macrographic testing methods for aerospace steels.
• EN 4500-5 – Details specific drafting and presentation rules for aerospace steel material standards.

Adherence to EN 4346:2007 guarantees that aerospace manufacturers use FE-PM1505 steel of consistent quality, optimized for performance, safety, and durability in critical aerospace applications. This standard aligns with the rigorous quality assurance frameworks required by the aerospace and defense industries, facilitating compliance and material traceability across European member states.