EN 3678:2025

Aerospace series - Steel X5CrNiCu17-4 (1.4542) - Air melted - Solution treated and precipitation treated - Forgings - a or D ≤ 200 mm - Rm ≥ 930 MPa

This document specifies the requirements relating to:
Steel X5CrNiCu17-4 (1.4542)
Air melted
Solution treated and precipitation treated
Forgings
a or D ≤ 200 mm
Rm ≥ 930 MPa
for aerospace applications.
W.nr: 1.4542.
ASD-STAN: FE-PM3801.

Luft- und Raumfahrt - Stahl X5CrNiCu17-4 (1.4542) - Lufterschmolzen - Lösungsgeglüht und ausscheidungsgehärtet - Schmiedestücke - a oder D ≤ 200 mm - Rm ≥ 930 MPa

No Scope available

Série aérospatiale - Acier X5CrNiCu17-4 (1.4542) - Élaboré à l'air - Mis en solution et précipité - Pièces forgées ou matricées - a ou D ≤ 200 mm - Rm ≥ 930 MPa

Le présent document spécifie les exigences relatives à :
Acier X5CrNiCu17-4 (1.4542)
Élaboré à l'air
Mis en solution et précipité
Pièces forgées ou matricées
a ou D ≤ 200 mm
Rm ≥ 930 MPa
pour les applications aérospatiales.
W.nr : 1.4542.
ASD-STAN : FE-PM3801.

Aeronavtika - Jeklo X5CrNiCu17-4 (1.4542) - Taljeno - Topilno žarjeno in izločevalno utrjeno - Izkovki - a ali D ≤ 200 mm - Rm ≥ 930 MPa

Ta dokument določa zahteve, ki se navezujejo na:  jeklo X5CrNiCu17-4 (1.4542), taljeno, topilno žarjeno in izločevalno utrjeno, izkovke, a ali D ≤ 200 mm, Rm ≥ 930 MPa za uporabo v aeronavtiki.  Št. W.: 1.4542.  Oznaka ASD-STAN: FE-PM3801.

General Information

• Status: Published
• Publication Date: 02-Dec-2025
• ICS: 49.025.10 - Steels
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 4/S 3 - Steels & Heat Resisting Alloys
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 03-Dec-2025
• Completion Date: 03-Dec-2025
• Ref Project: SIST EN 3678:2026 - Aerospace series - Steel X5CrNiCu17-4 (1.4542) - Air melted - Solution treated and precipitation treated - Forgings - a or D ≤ 200 mm - Rm ≥ 930 MPa

Relations

• Replaces: EN 3678:2007 - Aerospace series - Steel FE-PM3801 (X5CrNiCu17-4) - Air melted - Solution treated and precipitation treated - Forgings - a or D ≤ 200 mm - Rm ≥ 930 MPa
• Effective Date: 16-Mar-2022
• Refers: EN 4700-006:2025 - Aerospace series - Steel and heat-resisting alloys for wrought products - Technical specification - Part 006: Pre-production and production forgings
• Effective Date: 28-Jan-2026
• Refers: EN 4050-4:2012 - Aerospace series - Test method for metallic materials - Ultrasonic inspection of bars, plates, forging stock and forgings - Part 4: Acceptance criteria
• Effective Date: 28-Jan-2026
• Refers: EN 2951:2019 - Aerospace series - Metallic materials - Micrographic determination of content of non-metallic inclusions
• Effective Date: 28-Jan-2026
• Referred By: EN 4632-004:2012 - Aerospace series - Weldability and brazeability of materials in aerospace constructions - Part 004: Welding and brazing of homogeneous assemblies of high alloyed steels
• Effective Date: 28-Jan-2026

Overview

EN 3678:2025 is a European Standard developed by CEN, specifying requirements for the steel grade X5CrNiCu17-4 (1.4542), also known as 17-4 PH stainless steel, in the form of air melted, solution treated, and precipitation treated forgings. The standard covers products with a thickness or diameter (a or D) up to 200 mm and a minimum ultimate tensile strength (Rm) of 930 MPa, specifically designed for aerospace applications. This standard supersedes EN 3678:2007 and aligns with ASD-STAN designation FE-PM3801.

Key Topics

• Material Specification: Steel X5CrNiCu17-4 (1.4542), known for its high strength and corrosion resistance.
• Production Process: The standard applies to air melted forgings that undergo both solution treatment and precipitation hardening to achieve required mechanical properties.
• Dimensional Limits: Restricted to products with a thickness or diameter not exceeding 200 mm.
• Mechanical Properties: Requires a minimum tensile strength (Rm) of 930 MPa, with additional properties such as proof stress, elongation, and impact toughness specified.
• Quality and Test Methods:
  • Visual inspection (VT)
  • Ultrasonic testing (EN 4050-4) for internal imperfections
  • Microstructure evaluation, including δ-ferrite content and grain size
  • Inclusion content analysis (EN 2951)
  • Batch uniformity and marking inspection
• Heat Treatment: The delivery condition mandates solution treatment at 1,025°C to 1,055°C followed by precipitation treatment at 610°C to 630°C.

Applications

EN 3678:2025 is essential for manufacturers and suppliers providing high-performance steel forgings for the aerospace sector. The standard is particularly relevant for:

• Aircraft Structural Components: Structural fittings, landing gear parts, and other high-strength hardware where reliability is critical.
• Engine and Turbine Parts: Components that require a combination of mechanical strength and resistance to corrosion and high temperatures.
• Space Systems: Used in rocket, satellite, and spacecraft assemblies due to proven performance in demanding environments.
• Other High-Tech Industries: While optimized for aerospace, these steel forgings may also serve sectors such as defense, transportation, and advanced manufacturing.

The strict control over chemical composition, heat treatment, and mechanical properties ensures consistent quality and traceability, which are paramount in safety-critical aerospace applications.

Related Standards

To ensure comprehensive compliance and quality management, EN 3678:2025 references and aligns with several related European aerospace standards:

• EN 3163 - Aerospace series: Steel X5CrNiCu17-4 (1.4542) - Air melted - Softened - Forging stock (a or D ≤ 300 mm)
• EN 4258 - Aerospace series: Metallic materials - General organization of standardization
• EN 4500-005 - Aerospace series: Metallic materials - Rules for drafting and presentation of material standards - Specific rules for steels
• EN 2951 - Aerospace series: Metallic materials - Micrographic determination of content of non-metallic inclusions
• EN 4050-4 - Aerospace series: Ultrasonic inspection of bars, plates, forging stock, and forgings
• EN 4700-006 - Aerospace series: Steel and heat resisting alloys - Wrought products - Pre-production and production forgings

These referenced standards provide test methods, inspection criteria, and organizational guidelines crucial for maintaining material integrity, traceability, and compliance in aerospace manufacturing.

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By adhering to EN 3678:2025, organizations in the aerospace supply chain can ensure their forged steel components meet stringent European and international requirements for quality, performance, and safety.

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2026
Aeronavtika - Jeklo X5CrNiCu17-4 (1.4542) - Taljeno - Topilno žarjeno in
izločevalno utrjeno - Izkovki - a ali D ≤ 200 mm - Rm ≥ 930 MPa
Aerospace series - Steel X5CrNiCu17-4 (1.4542) - Air melted - Solution treated and
precipitation treated - Forgings - a or D ≤ 200 mm - Rm ≥ 930 MPa
Luft- und Raumfahrt - Stahl X5CrNiCu17-4 (1.4542) - Lufterschmolzen - Lösungsgeglüht
und ausscheidungsgehärtet - Schmiedestücke - a oder D ≤ 200 mm - Rm ≥ 930 MPa
Série aérospatiale - Acier X5CrNiCu17-4 (1.4542) - Élaboré à l'air - Mis en solution et
précipité - Pièces forgées ou matricées - a ou D ≤ 200 mm - Rm ≥ 930 MPa
Ta slovenski standard je istoveten z: EN 3678:2025
ICS:
49.025.10 Jekla Steels
77.140.85 Železni in jekleni kovani Iron and steel forgings
izdelki
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 3678
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2025
EUROPÄISCHE NORM
ICS 49.025.10 Supersedes EN 3678:2007
English Version
Aerospace series - Steel X5CrNiCu17-4 (1.4542) - Air
melted - Solution treated and precipitation treated -
Forgings - a or D  200 mm - Rm  930 MPa
Série aérospatiale - Acier X5CrNiCu17-4 (1.4542) - Luft- und Raumfahrt - Stahl X5CrNiCu17-4 (1.4542) -
Élaboré à l'air - Mis en solution et précipité - Pièces Lufterschmolzen - Lösungsgeglüht und
forgées ou matricées - a ou D  200 mm - Rm  930 ausscheidungsgehärtet - Schmiedestücke - a oder D 
MPa
200 mm - Rm  930 MPa
This European Standard was approved by CEN on 5 October 2025.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3678:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Requirements . 5
Bibliography . 9

European foreword
This document (EN 3678:2025) has been prepared by ASD-STAN.
After enquiries and votes carried out in accordance with the rules of this Association, this document has
received the approval of the National Associations and the Official Services of the member countries of
ASD-STAN, prior to its presentation to CEN.
This document shall be given the status of a national standard, either by publication of an identical text
or by endorsement, at the latest by June 2026, and conflicting national standards shall be withdrawn at
the latest by June 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 3678:2007.
— update of the material designation;
— correction of the format of Table 1 to comply with the requirements of the EN 4500 series;
— update of Clause 2;
— addition of a bibliography.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this document: Austria, Belgium, Bulgaria, Croatia, Cyprus,
Czech Republic, D
...