ASD-STAN PREN 4268-2010 Aerospace series Metallic materials Heat treatment facilities General requirements (Edition P 1).pdf

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1、ASD-STAN STANDARD NORME ASD-STAN ASD-STAN NORM prEN 4268 Edition P 1 September 2010 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATIONAvenue de Tervuren, 270 - B-1150 Brussels - Tel. + 32 2 775 8126 - Fax. + 32 2 775 8131 - www.asd-stan.orgICS: 49.060 Descripto

2、rs: ENGLISH VERSION Aerospace series Metallic materials Heat treatment facilities General requirements Srie arospatiale Matriaux mtalliques Installations de traitement thermique Exigences gnrales Luft- und Raumfahrt Metallische Werkstoffe Wrmebehandlungsanlagen Allgemeine Anforderungen This “Aerospa

3、ce Series“ Prestandard has been drawn up under the responsibility of ASD-STAN (The AeroSpace and Defence Industries Association of Europe - Standardization). It is published for the needs of the European Aerospace Industry. It has been technically approved by the experts of the concerned Domain foll

4、owing member comments. Subsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of the standard. After examination and review by users and formal agreement of

5、ASD-STAN, it will be submitted as a draft European Standard (prEN) to CEN (European Committee for Standardization) for formal vote and transformation to full European Standard (EN). The CEN national members have then to implement the EN at national level by giving the EN the status of a national sta

6、ndard and by withdrawing any national standards conflicting with the EN. Edition approved for publication 1 September 2010 Comments should be sent within six months after the date of publication to ASD-STAN Metallic Material Domain Copyright 2010 by ASD-STAN prEN 4268:2010 (E) 3 Contents Page Forewo

7、rd .3 1 Scope4 2 Normative references4 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 quenchants6 5.5 Temperature sensors7 5.6 Designation 8 5.7 Temperature setting (W) and

8、 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 instruments11 6.3 Test frequency.11 6.4 Extent of testing 11 6.5 Test procedures.11 7 Test results and documentation 14 7.1

9、 Evaluation of temperature measurement14 7.2 Evaluation of temperature uniformity .14 7.3 Documentation of test results14 Foreword This standard was reviewed by the Domain Technical Coordinator of ASD-STANs Metallic Material Domain. After inquiries and votes carried out in accordance with the rules

10、of ASD-STAN defined in ASD-STANs General Process Manual, this standard has received approval for Publication. prEN 4268:2010 (E) 4 1 Scope This standard covers the general requirements for heat treatment facilities processing semi-finished products and parts in metallic aerospace materials. It defin

11、es 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

12、 direct or indirect heat transfer and liquid or gaseous heating media, with our without circulation, and to vacuum furnaces. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For und

13、ated references, the latest edition of the referenced document (including any amendments) applies. IEC 584-2, Thermocouples Part 2: Tolerances 1)3 General The heat treatment of metallic materials produces specific material properties only if performed within relatively narrow temperature ranges, the

14、 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

15、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 treat

16、ment. 4 Terms and definitions For the purposes of this document, the following terms and definitions apply. 4.1 temperature uniformity temperature uniformity is a measure of the temperature variation at various points in the effective working volume after thermal equilibrium has been reached 4.2 eff

17、ective 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 Internat

18、ional Commission Electrotechnique Internationale http:/www.iec.ch/ (CENELEC EN 60584-2). prEN 4268:2010 (E) 5 4.3 maximum temperature variation the maximum temperature variation indicates how much the temperatures at different points in the effective working volume are allowed to vary from the worki

19、ng 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 eq

20、uilibrium 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 a feature permitting analog o

21、r 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

22、.9 working temperature range the range extending from the lowest to the highest working temperature at which the heat treatment facility is to be operated NOTE A code number identifies the maximum allowable working temperature. 4.10 test temperature agreed temperature at which the reference measurem

23、ent is to be made or the temperature uniformity to be demonstrated 4.11 temperature sensors this term denotes temperature-sensing elements for the various measuring, control and recording functions 4.12 recording sensor this is the temperature-sensing element of a chain of validly indicating and rec

24、ording instruments 4.13 approval for the purposes of the present standard, approval is the formal release of a facility for production heat treatment NOTE It is granted if compliance with the requirements of the present standard has been demonstrated by acceptance testing. prEN 4268:2010 (E) 6 5 Hea

25、t 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 su

26、bjected 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

27、 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 differ

28、ent working temperature ranges. Table 1 Maximum permissible temperature variation of effective working volume Working temperature range Maximum permissible temperature variation C C Category Code number A B C D 03 300 7,5 5 3 07 300 1 h: PV 10 mm/h R 1,5 C RK = 0,3 RA 3 C/mm for WBD 1 h: PV 30 mm/h

29、for WBD 1 h: PV 20 mm/h R 1 C RK = 0,2 RA 2 C/mm for WBD 2 h: PV 40 mm/h for WBD 2 h: PV 20 mm/h 07 300 1 h: PV 10 mm/h R 2 C RK = 0,3 RA 4 C/mm for WBD 1 h: PV 30 mm/h for WBD 1 h:PV 20 mm/h R 1,5 C RK = 0,2 RA 3 C/mm for WBD 2 h: PV 40 mm/h for WBD 2 h: PV 20 mm/h 10 700 1 h:PV 10 mm/h R 3 C RK =

30、0,3 RA 6 C/mm for WBD 1 h: PV 30 mm/h for WBD 1 h:PV 20 mm/h R 2 C RK = 0,2 RA 4 C/mm for WBD 2 h: PV 40 mm/h for WBD 2 h: PV 20 mm/h R 2 C RK = 0,1 RA 4 C/mm for WBD 2 h:PV 40 mm/h for WBD 2 h:PV 20 mm/h 13 1 000 1 h:PV 10 mm/h R 4 C RK = 0,3 RA 8 C/mm for WBD 1 h: PV 30 mm/h for WBD 1 h:PV 20 mm/h

31、 R 3 C RK = 0,2 RA 6 C/mm for WBD 2 h: PV 40 mm/h for WBD 2 h: PV 20 mm/h R 3 C RK = 0,1 RA 6 C/mm for WBD 2 h:PV 40 mm/h for WBD 2 h:PV 20 mm/h 6 Tests 6.1 General The heat treatment facility shall be so designed as to permit performance of the specified tests (e.g. additional lead-ins for temperat

32、ure sensors, ready accessibility of equipment, concurrent readouts from facility instrumentation and independent test instrumentation). prEN 4268:2010 (E) 11 Testing shall invariably be performed using independent test instruments. 6.2 Test instruments The accuracy of test instruments shall be at le

33、ast equivalent to or better than that of the facility working instruments. Test instrument deviations shall be known. Test instruments shall likewise be subjected to periodic checks. The working instruments are calibrated against the test instruments, which are themselves calibrated against chains o

34、f standard instruments traceable to standards maintained by internationally recognized standards organizations, responsible for establishing National Standards. Test instruments shall be checked at a frequency of every 3 months, 6 months or 12 months or as specified by the manufacturer. In the case

35、of temperature sensors (thermocouples), the frequency also depends on the thermocouple wire diameter, service time, temperature level and heating medium. 6.3 Test frequency The time interval between tests is governed by so-called “dynamic test frequencies“, where k = reduced frequency; n = normal fr

36、equency; l = extended frequency. The first test following acceptance, repair, alteration or relocation of the facility shall be made at frequency “k“, tests thereafter at frequency “n“. If no anomalies are found in three consecutive tests, the frequency requirement may be changed to “l“. When irregu

37、larities or deviations are found in operation or use, the frequency shall again revert to “k“. 6.4 Extent of testing Tests are classified into: a) Category I - accuracy test; b) Category II - temperature uniformity test; c) Category III - instrument test. Testing required for acceptance or subsequen

38、t to relocation: a) Categories I, II, III. Testing required upon alteration or repair, depending on the type and extent of the rework: b) Categories I, II and/or III. 6.5 Test procedures 6.5.1 Accuracy test (V) and test frequency (TV) Accuracy testing involves checking a heat treatment facilitys cha

39、in of validly indicating and recording temperature instruments against a reference chain installed for calibration purposes. The reference sensor shall be located as close as possible to the facilitys recording sensor. prEN 4268:2010 (E) 12 The permissible temperature variations and the test frequen

40、cies are shown in Table 6. Table 6 Maximum permissible temperature variation in accuracy test (V) and test frequency (TV) Working temperature range Category Code number C A B C D 03 300 V = 4 C TV: k = 1 month n = 2 months l = 4 months V = 3 C TV: k = 1/2 month n = 1 month l = 2 months V = 2 C TV: k

41、 = 1 week n = 2 weeks l = 4 weeks 07 300 700 V = 5 C TV: as code number 03 V = 3 C TV: as code number 03 V = 3 C TV: as code number 03 10 700 1 000 V = 8 C TV: as code number 03 V = 5 C TV: as code number 03 V = 4 C TV: as code number 03 V = 3 C TV: k = 1 week n = 2 weeks l = 4 weeks 13 1 000 1 300

42、V = 9 C TV: as code number 03 V = 6 C TV: as code number 03 V = 5 C TV: as code number 03 V = 3 C TV: k = 1 week n = 2 weeks l = 4 weeks 6.5.2 Temperature uniformity test and test frequency (TT) 6.5.2.1 General The temperature uniformity tests shall be performed by means of thermocouples in the heat

43、 treatment facility or the heating medium at frequencies as given in Table 7. The survey can be made optionally with or without production load. With no production load being present, care shall be taken to ensure that the temperature distribution pattern is affected as little as possible by any sup

44、port device necessary for the thermocouples. The temperature measurements shall be taken after the furnace or bath has reached thermal equilibrium. The duration of the measurement shall be selected so that the results provide conclusive evidence of temperature uniformity. Also the time intervals dur

45、ing a measurement shall be selected such that the temperature minima and maxima, depending on the closed-loop oscillations, are sensed. prEN 4268:2010 (E) 13 Table 7 Temperature uniformity test frequency (TT) Working temperature range Category Code number C A B C D 03 300 07 300 700 10 700 1 000 13

46、1 000 1 300 TT: k = 12 months n = 15 months l = 21 months TT: k = 9 months n = 12 months l = 18 months TT: k = 4 months n = 6 months l = 12 months TT: k = 4 months n = 6 months l = 12 months 6.5.2.2 Furnace temperature uniformity survey The arrangement of the test locations in the furnace shall be r

47、egularly distributed in the effective working volume, as far as possible. a) Attach the thermocouples to the rack or the production load. b) Load the rack or production load into the effective working volume. c) Heat the effective working volume to test temperature and keep the control setting const

48、ant thereafter. d) Start measurement after thermal equilibrium has been reached. e) Thereafter, record the test locations at intervals of at least two closed-loop oscillations, recording the temperature minima and maxima. f) Record and read the temperature on an independent recorder. 6.5.2.3 Salt ba

49、th temperature uniformity survey The temperature uniformity in salt baths is determined by using a temperature sensor enclosed in a suitable protection tube. The temperature sensor is held in one position until thermal equilibrium has been reached and a reading made. The temperature sensor shall then be placed in a new location an