SIST EN 3971:2009

• Abstract:

  This standard specifies the requirements relating to:; Steel FE-PL1507 (40CrMoV12); Consumable electrode remelted; Annealed; Forging stock; a or D ≤ 350 mm; for aerospace applications.

• Status: Published
• Publication Date: 31-Mar-2009
• ICS: 49.025.10 - Steels
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 20-Mar-2009
• Due Date: 25-May-2009
• Completion Date: 01-Apr-2009
• Ref Project: EN 3971:2006 - Aerospace series - Steel FE-PL1507 (40CrMoV12) - Consumable electrode remelted - Annealed - Forging stock - a or D ≤ 350 mm

• Refers: SIST EN 4258:2024 - Aerospace series - Metallic materials - General organization of standardization - Link between types of European Standards and their use
• Effective Date: 28-Jan-2026
• Refers: SIST EN 2157-2:2001 - Aerospace series - Steel - Forging stock and forgings - Technical specification - Part 2: Forging stock
• Effective Date: 28-Jan-2026
• Referred By: SIST EN 4098:2007 - Aerospace series - Steel FE-PL1507 (40CrMoV12) - Remelted, hardened and tempered, forgings De <= 50 mm, 1 250 MPa <= Rm <= 1 400 MPa
• Effective Date: 28-Jan-2026
• Referred By: SIST EN 4632-003:2010 - Aerospace series - Weldability and brazeability of materials in aerospace constructions - Part 003: Welding and brazing of homogeneous assemblies of unalloyed and low alloy steels
• Effective Date: 28-Jan-2026
• Referred By: SIST EN 4098:2026 - Aerospace series - Steel 40CrMoV12 (1.8523) - Consumable electrode remelted - Hardened and tempered - Forgings - De ≤ 50 mm - 1 250 MPa ≤ Rm ≤ 1 400 MPa
• Effective Date: 28-Jan-2026

SIST EN 3971:2009 is a Slovenian adoption of EN 3971:2006 for aerospace steel FE-PL1507 (40CrMoV12). It specifies requirements for consumable electrode remelted, annealed forging stock within the size limit shown in the title. The standard is meant for suppliers, purchasers, inspectors and test labs that need a defined material condition for aerospace applications.

What does SIST EN 3971:2009 specify?

SIST EN 3971:2009 specifies the requirements for steel FE-PL1507 (40CrMoV12) supplied as consumable electrode remelted and annealed forging stock for aerospace use. Its structure is simple: scope, normative references, and a detailed requirements table with supporting notes.

The requirements table brings together chemistry, melting route, product form, delivery condition, test sampling, mechanical properties, metallurgical checks, marking, dimensional inspection and product qualification. In practice, that means the standard is not just a chemistry description - it is the full acceptance framework for the material as supplied.

What are the key requirements of SIST EN 3971:2009?

SIST EN 3971:2009 sets out the material condition, property targets and inspection rules that a supplier must meet before the forging stock can be accepted for aerospace work.

• Material and supply condition - The standard covers steel FE-PL1507 (40CrMoV12) in the consumable electrode remelted and annealed condition, supplied as forging stock. For a buyer, this fixes both the metallurgical route and the delivery state, so the ordered product is unambiguous.

• Chemical control - The composition is specified for the main alloying and impurity elements, with an additional note on combined phosphorus and tin content. In practice, the melt analysis has to stay within the specified chemistry window to keep forging and heat-treatment behaviour consistent.

• Form and size - The product is forging stock, not finished forged parts, and the size limit is defined in the title. This matters because the standard is aimed at semi-finished stock that will later be forged into aerospace parts.

• Mechanical properties - The table defines acceptance criteria for proof stress, tensile strength, elongation, reduction of area, hardness and impact strength, including the test orientation. This is the basis for batch release and for checking that the steel has the required strength and toughness after the specified treatment.

• Sampling and test pieces - Sampling and specimen preparation are tied to EN 2157-2 and EN 2957, with specific guidance on sample source and test-piece direction. For users, this ensures that test results are comparable and traceable to the supplied stock.

• Heat treatment control - The document gives a reference heat treatment and requires the actual heat-treatment temperature and time to be reported on the inspection and test report. That means the thermal history of the material is part of the quality record, not just a shop-floor detail.

• Metallurgical quality and defects - Grain size, cleanliness/inclusion content, macrostructure, external defects and internal defects are all checked using the referenced methods and defect classifications. This helps screen out segregation, freckling, white spots and other internal quality issues before the material enters aerospace production.

• Qualification, marking and dimensions - Product qualification follows EN 2043, while marking and dimensional inspection follow EN 2157-2. In practice, the supplier has to provide both the technical evidence and the identification needed for acceptance and traceability.

What terms does SIST EN 3971:2009 define?

• FE-PL1507 - The material designation for the steel grade covered by the standard.
• 40CrMoV12 - The alternative steel designation used with FE-PL1507 in the document.
• Consumable electrode remelted - The melting route used to produce the steel before delivery.
• Annealed - The delivery condition after heat treatment in which the forging stock is supplied.
• Forging stock - Semi-finished material intended to be forged into a final part.
• L or LT - The permitted test-piece directions used when mechanical specimens are prepared.
• EN 2157-2 - The aerospace technical specification that the standard uses for forging stock requirements, marking and dimensional control.
• EN 2043 - The aerospace qualification standard used for product qualification.

Who uses SIST EN 3971:2009?

SIST EN 3971:2009 is used by aerospace material suppliers, forging stock manufacturers, heat-treatment shops, test laboratories, purchasers and quality teams. They use it to order the right steel, prepare inspection plans, qualify product, review certificates and accept or reject delivered stock.

What changed in SIST EN 3971:2009 from the previous edition?

SIST EN 3971:2009 is identical to EN 3971:2006.

Which standards are used with SIST EN 3971:2009?

• EN 2002-8 - Gives the method for micrographic determination of grain size.
• EN 2003-7 - Gives the macrographic test method for steel.
• EN 2043 - Provides the general requirements for semi-finished product qualification.
• EN 2157-2 - Provides the technical specification for forging stock, including related inspection and identification rules.
• EN 2957 - Gives the method for preparation of forged samples.
• EN 4258 - Sets the general organization of aerospace metallic material standards.
• EN 4500-5 - Sets the drafting and presentation rules used for steel material standards.

What does the SIST EN 3971:2009 document contain?

The document contains a requirements table covering chemistry, melting route, form, delivery condition, sampling, test orientation, properties, defect checks, marking, dimensions and qualification. It also includes notes that control how heat treatment is reported, how optional impact testing is treated, and how the material is typically used.

Its test and inspection content is tied to the named EN methods, so the document serves as both a material specification and a test/acceptance reference. For users, that means it can support ordering, receiving inspection, laboratory testing and qualification of aerospace forging stock.

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Ta slovenski standard je istoveten z: EN 3971:2006
ICS:
49.025.10 Jekla Steels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 3971
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2006
ICS 49.025.10
English Version
Aerospace series - Steel FE-PL1507 (40CrMoV12) -
Consumable electrode remelted - Annealed - Forging stock - a
or D ≤ 350 mm
Série aérospatiale - Acier FE-PL1507 (40CrMoV12) - Luft- und Raumfahrt - Stahl FE-PL1507 (40CrMoV12) - Mit
Refondu à l'électrode consommable - Recuit - Produits selbstverzehrender Elektrode umgeschmolzen - Geglüht -
destinés à la forge - a ou D ≤ 350 mm Schmiedevormaterial - a oder D ≤ 350 mm
This European Standard was approved by CEN on 18 October 2006.

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© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3971:2006: E
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Foreword
This document (EN 3971:2006) has been prepared by the Aerospace and Defence Industries Association of
Europe - Standardization (ASD-STAN).
After enquiries and votes carried out in accordance with the rules of this Association, this Standard has
received the approval of the National Associations and the Official Services of the member countries of ASD,
prior to its presentation to CEN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by June 2007, and conflicting national standards shall be withdrawn at
the latest by June 2007.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden,
Switzerland and the United Kingdom.
Introduction
This standard is part of the series of EN metallic material standards for aerospace applications. The general
organization of this series is described in EN 4258.
This standard has been prepared in accordance with EN 4500-5.
1 Scope
This standard specifies the requirements relating to:
Steel FE-PL1507 (4
...