Aerospace series - Metallic materials - Heat treatment facilities - General requirements

This European Standard covers the general requirements for heat treatment facilities processing semi-finished products and parts in metallic aerospace materials.
It defines the terms used herein and describes the test procedures and requirements for mandatory tests of heat treatment facilities. It also serves as an aid in the surveillance and approval of heat treatment facilities.
This standard applies to all types of heat treatment facilities, including those using direct or indirect heat transfer and liquid or gaseous heating media, with our without circulation, and to vacuum furnaces.

Luft- und Raumfahrt - Metallische Werkstoffe - Wärmebehandlungsanlagen - Allgemeine Anforderungen

Diese Europäische Norm umfasst die allgemeinen Anforderungen an Wärmebehandlungsanlagen, in denen Halbzeug und metallische Teile für die Luft- und Raumfahrt hergestellt werden.
Sie definiert die verwendeten Begriffe und beschreibt Verfahren zur Überprüfung von Wärme¬behandlungs-anlagen und zugehörige Anforderungen. Sie dient außerdem als Hilfe bei der Überwachung und Zulassung von Wärmebehandlungsanlagen.
Diese Norm ist auf alle Arten von Wärmebehandlungsanlagen anwendbar, einschließlich solcher, die direkte oder indirekte Wärmeübertragung und zirkulierende oder nicht zirkulierende, flüssige oder gasförmige Heizmedien verwenden sowie auf Vakuumöfen.

Série aérospatiale - Matériaux métalliques - Installations de traitement thermique - Exigences générales

Aeronavtika - Kovinski materiali - Naprave za toplotno obdelavo - Splošne zahteve

General Information

Status
Published
Publication Date
02-Oct-2012
Technical Committee
Drafting Committee
Current Stage
9093 - Decision to confirm - Review Enquiry

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SLOVENSKI STANDARD
SIST EN 4268:2014
01-marec-2014

Aeronavtika - Kovinski materiali - Naprave za toplotno obdelavo - Splošne zahteve

Aerospace series - Metallic materials - Heat treatment facilities - General requirements

Luft- und Raumfahrt - Metallische Werkstoffe - Wärmebehandlungsanlagen - Allgemeine

Anforderungen

Série aérospatiale - Matériaux métalliques - Installations de traitement thermique -

Exigences générales
Ta slovenski standard je istoveten z: EN 4268:2012
ICS:
25.200 Toplotna obdelava Heat treatment
49.025.05 Železove zlitine na splošno Ferrous alloys in general
49.025.15 Neželezove zlitine na Non-ferrous alloys in general
splošno
SIST EN 4268:2014 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 4268:2014
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SIST EN 4268:2014
EUROPEAN STANDARD
EN 4268
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2012
ICS 25.200; 49.025.05; 49.025.15
English Version
Aerospace series - Metallic materials - Heat treatment facilities -
General requirements

Série aérospatiale - Matériaux métalliques - Installations de Luft- und Raumfahrt - Metallische Werkstoffe -

traitement thermique - Exigences générales Wärmebehandlungsanlagen - Allgemeine Anforderungen

This European Standard was approved by CEN on 15 July 2011.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United

Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 4268:2012: E

worldwide for CEN national Members.
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SIST EN 4268:2014
EN 4268:2012 (E)
Contents Page

Foreword ..............................................................................................................................................................3

1 Scope ......................................................................................................................................................4

2 Normative references ............................................................................................................................4

3 General ....................................................................................................................................................4

4 Terms and definitions ...........................................................................................................................4

5 Heat treatment facility requirements ...................................................................................................6

5.1 General ....................................................................................................................................................6

5.2 Category classification .........................................................................................................................6

5.3 Heating media ........................................................................................................................................6

5.4 Quenching equipment and quenchants ..............................................................................................6

5.5 Temperature sensors ............................................................................................................................7

5.5.1 General ....................................................................................................................................................7

5.5.2 Temperature sensor accuracy (M) .......................................................................................................7

5.5.3 Number and distribution of recording sensors ..................................................................................7

5.6 Designation ............................................................................................................................................8

5.7 Temperature setting (W) and indicating accuracy (A) .......................................................................8

5.8 Accuracy of recorder (R), grade of accuracy (RK), resolution of recording (RA) and rate of

paper feed (PV) .......................................................................................................................................9

6 Tests ..................................................................................................................................................... 10

6.1 General ................................................................................................................................................. 10

6.2 Test instruments ................................................................................................................................. 11

6.3 Test frequency .................................................................................................................................... 11

6.4 Extent of testing .................................................................................................................................. 11

6.5 Test procedures .................................................................................................................................. 11

6.5.1 Accuracy test (V) and test frequency (TV) ....................................................................................... 11

6.5.2 Temperature uniformity test and test frequency (TT) ..................................................................... 12

6.5.3 Instrument test (PG) and instrument test frequency (TPG) ........................................................... 13

7 Test results and documentation ....................................................................................................... 14

7.1 Evaluation of temperature measurement ......................................................................................... 14

7.2 Evaluation of temperature uniformity ............................................................................................... 14

7.3 Documentation of test results ........................................................................................................... 14

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SIST EN 4268:2014
EN 4268:2012 (E)
Foreword

This document (EN 4268:2012) 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 April 2013, and conflicting national standards shall be withdrawn at the

latest by April 2013.

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 organisations of the following

countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech

Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,

Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,

Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

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SIST EN 4268:2014
EN 4268:2012 (E)
1 Scope

This European Standard covers the general requirements for heat treatment facilities processing semi-finished

products and parts in metallic aerospace materials.

It defines the terms used herein and describes the test procedures and requirements for mandatory tests of

heat treatment facilities. It also serves as an aid in the surveillance and approval of heat treatment facilities.

This standard applies to all types of heat treatment facilities, including those using direct or indirect heat

transfer and liquid or gaseous heating media, with our without circulation, and to vacuum furnaces.

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated references,

the latest edition of the referenced document (including any amendments) applies.

IEC 60584-2, Thermocouples — Part 2: Tolerances
3 General

The heat treatment of metallic materials produces specific material properties only if performed within

relatively narrow temperature ranges, the respective tolerances of which are specified in the applicable

standards. A heat treatment facility can therefore be used for a heat-treating operation only provided its

temperature variations over space and time remain within the specified temperature tolerance.

Proper temperature distribution in the heat treatment facility depends on e.g. the type of furnace or bath, the

heating medium, the control instruments with their feedback and run-up circuitry, and the rigging and

positioning of control sensors.

A suitable recording instrument is needed to properly monitor and document the heat treatment.

4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1
temperature uniformity

measure of the temperature variation at various points in the effective working volume after thermal

equilibrium has been reached
4.2
effective working volume

for the purposes of the present standard, the effective working volume is the working zone of the heat

treatment facility in which temperatures run within the specified maximum temperature variation and which is

available for the intended heat treatment

1) Published by International Commission Electrotechnique Internationale http://www.iec.ch/ (CENELEC

EN 60584-2).
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SIST EN 4268:2014
EN 4268:2012 (E)
4.3
maximum temperature variation

maximum temperature variation indicates how much the temperatures at different points in the effective

working volume are allowed to vary from the working temperature after thermal equilibrium has been reached

4.4
category classification

depending on their technical characteristics, heat treatment furnaces or baths are classified into 4 categories

A, B, C, D of different maximum temperature variation (see Table 1)
4.5
thermal equilibrium

thermal equilibrium is reached when following the temperature rise phase no validly recorded temperature

varies by more than 20 % of the maximum allowable temperature variation in the effective working volume for

the duration of one closed-loop oscillation
4.6
temperature setting

feature permitting analog or digital reproducible selection of the facility temperature set-point

4.7
correction factor

this is the correction applied to the set-point to achieve the specified working temperature

4.8
working temperature

temperature to which the heat treatment facility is brought for a certain heat treatment

4.9
working temperature range

range extending from the lowest to the highest working temperature at which the heat treatment facility is to

be operated

Note 1 to entry: A code number identifies the maximum allowable working temperature.

4.10
test temperature

agreed temperature at which the reference measurement is to be made or the temperature uniformity to be

demonstrated
4.11
temperature sensors

temperature-sensing elements for the various measuring, control and recording functions

4.12
recording sensor

temperature-sensing element of a chain of validly indicating and recording instruments

4.13
approval

for the purposes of the present standard, approval is the formal release of a facility for production heat

treatment

Note 1 to entry: It is granted if compliance with the requirements of the present standard has been demonstrated by

acceptance testing.
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SIST EN 4268:2014
EN 4268:2012 (E)
5 Heat treatment facility requirements
5.1 General

Heat treatment facilities shall be capable of satisfying the requirements of the heat treatment process to be

applied.

Heat treatment facilities as defined in Clause 1 shall be approved prior to their release for production heat

treatment and shall be subjected to periodic in-service checks. Approval and periodic checks shall be

performed by the responsible company quality assurance, facilities support and calibration activities.

Approval and periodic checks shall be in conformance with the requirements of Clause 6.

In the case of safety tests, the competent specialist department shall be consulted. The test results shall be

reported by the competent specialist department and filed with the heat treatment facility records.

5.2 Category classification

A heat treatment facility may fall within several categories if designed to operate in different working

temperature ranges.
Table 1 — Maximum permissible temperature variation of effective working volume
Working Maximum permissible
temperature range temperature variation
Code
°C °C
number
Category
A B C D
03 –
θ ≤ 300 ± 7,5 ± 5 ± 3
07 –
300 < θ ≤ 700 ± 10 ± 7,5 ± 5
700 < θ ≤ 1 000 ± 15 ± 10 ± 7,5 ± 5
1 000 < θ ≤ 1 300 ± 20 ± 15 ± 10 ± 5

Where a working temperature range of a facility is less than the maximum value given in Table 1, the

corresponding code number shall be indicated in the designation as outlined in 5.6.

5.3 Heating media

Heating media shall be selected so as to avoid changes in the material surfaces during the heat treatment

operation affecting the operational properties of the parts, unless such changes are allowed or specified in the

material standards or design documents. Heating media,
...

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