1、AECMA PREN*27Lb b 1012311 0010723 OT7 Edition approved for publication 1996-02-29 AECMA STANDARD NORME AECMA AECMA NORM C5 Chairman Mr Odorico Comments should be sent within six months after the date of publication to AECMA Gulledelle 94 6-1 200 BRUXELLES prEN 271 6 Edition P2 February 1996 PUBLISHE
2、D BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES AECMA) Gulledelle 94 - 6-1 200 BRUXELLES - Tel. (32) 2 775 81 10 - Fax. (32) 2 775 81 11 ICs ENGLISH VERSION Supersedes issue P1 October 1990 Aerospace series Test method Determination of susceptibility to intergranular corrosion Wrought aluminiu
3、m alloy products AL-P2XXX- series, AL-P7XXX- series and aluminium-lithium alloys Srie arospatiale Mthodes dessai Dtermination de la susceptibilit la corrosion intergranulaire Produits corroys en alliages daluminium srie AL-P2XXX-, srie AL-P7XXX- et alliages daluminium-lithium Luft- und Raumfahrt Prf
4、verfahren Bestimmung der Anflligkeit fr interkristalline Korrosion Aluminium-Kneterzeugnisse aus AL-P2XXX-, AL-P7XXX- und Aluminium-Lithium-Legierung This “Aerospace Series“ Prestandard has been drawn up under the responsibility of AECMA (The European Association of Aerospace Industries). It is publ
5、ished on green paper for the needs of AECMA-Members. It has been technically approved by the experts of the concerned Technical Committee following comment by the Member countries. Subsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interch
6、angeability is affected, physically or functionally, without re-identification of the standard. After examination and signature of the AECMA Standard Checking Centre (NPS) and formal agreement of the Official Services of the Member countries it will be submitted as a draft European Standard to CEN (
7、European Committee for Standardization) for formal vote. COPYRIGHT Association Europeene Des Constructeurs de Materiel AerospaceLicensed by Information Handling Services AECMA PRENx271b Yb m LOL23LL 00110724 T33 m Page 2 prEN 2716 : 1996 Contents list I Scope 2 Test procedure 3 Microscopic examinati
8、on 4 Acceptance criteria COPYRIGHT Association Europeene Des Constructeurs de Materiel AerospaceLicensed by Information Handling Services AECMA PREN*271b 96 m 1012311 0010725 97T m Nitric acid 70 % concentrated Hydrofluoric acid 40 % concentrated Demineralised or deionised water Page 3 prEN 271 6 :
9、1996 5 0,s 94,5 1 Scope NaCI analytical grade Hydrogen peroxide 30 % concentration Demineralised or deionised water This standard specifies the procedure for the determination of the susceptibility to intergranular corrosion of wrought aluminium alloys in AL-P2XXX- series, AL-P7XXX- series and alumi
10、nium-lithium alloy products. It does not consider health and safety requirements. It is the responsibility of the user to adopt appropriate health and safety precautions when hazardous substances are involved. 57 9 10 ml make up to 1000 ml 2 Test procedure 2.1 Test sample location Unless otherwise a
11、greed between manufacturer and purchaser, the manufacturer shall define and record the location of the test sample. The test direction shall be parallel to the direction of working. 2.2 Preparation of test samples Test samples shall be prepared as follows : - for clad products remove the cladding by
12、 a suitable method ; - degrease the test sample in acetone ; - immerse the test sample for 1 min in the solution shown in table 1 at a temperature of 95 oc I5 oc. Table 1 I Reagents I % vol. I - rinse in demineralised or deionised water ; - desmutt in nitric acid 70 % concentrated at ambient tempera
13、ture : - rinse in demineralised or deionised water ; - dry. 2.3 Intergranular corrosion test The test samples, prepared in accordance with 2.2, shall be immersed vertically, in a freshly prepared test solution to table 2, at a temperature of 25 OC f 5 OC. Table 2 Reagents I Quantity 1 The volume of
14、solution used shall not be less than 10 ml of solution per square centimetre of specimen surface area. When several samples of the same alloy are immersed together, the samples shall be electrically isolated from each other and the volume of solution shall conform to the above requirement. The time
15、of immersion shall be 6 h. After immersion, remove and rinse the test samples in demineralised or deionised water and dry COPYRIGHT Association Europeene Des Constructeurs de Materiel AerospaceLicensed by Information Handling ServicesAECMA PRENr273b 96 W 3012333 0030726 806 Reagents Nitric acid 70 %
16、 concentrated Page 4 prEN 271 6 : 1996 Yo vol. 2,s 3 Microscopic examination 3.1 From the area exhibiting the most severe surface corrosion attack, a section at least 20 mm long shall be taken perpendicular to the direction of working and prepared for micrographic examination by polishing. This micr
17、o-section shall be examined at a magnification from 100 times to 500 times. 3.2 table 3 at ambient temperature and than re-examined : After an initiai examination, the prepared micro-section shall be etched using the etchant in Table 3 I Hydrochloric acid 35 % concentrated I 1,5 I I Hydrofluoric aci
18、d 40 % concentrated I 1 I I Demineralised or deionised water I 95 I The time of immersion shall not exceed 30 s. 4 Acceptance criteria The results of the examination shall meet the requirements of the relevant technical specification, material standard, drawing, order or inspection schedule. COPYRIGHT Association Europeene Des Constructeurs de Materiel AerospaceLicensed by Information Handling Services
