1、STD-AECMA PREN 2899-ENGL 1977 LOL23LL OCIL2131 5b2 m AECMA STANDARD prEN 2899 Edition P 1 NORME AECMA AECMA NORM February 1997 C7 Chairman Mr Wright Edition approved for publication Comments should be sent within six months after the date of publication to AECMA Gulledelle 94 1997-02-28 E-1 200 BRUX
2、ELLES aecma 199 PUBLISHED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Gulledelle 94 - B-1200 BRUXELLES - Tel. (32) 2 775 81 10 - Fax. (32) 2 775 81 11 ICs : Descriptors : ENGLISH VERSION Aerospace series Vulcanized rubbers Tests on the susceptibility to corrosion in a damp atmosphere
3、 of metals in contact with vulcanized rubbers Srie arospatiale Luft- und Raumfahrt lastomres vulcaniss Vulkanisierte Elastomere Essais de sensibilit la corrosion en atmosphre humide des mtaux au contact des lastomres vulcaniss Prfung der Korrosionsempfindlichkeit in Feuchtklima von Metallen bei Berh
4、rung mit vulkanisierten Elastomeren This lerospace Series“ Prestandard has been drawn up under the responsibility of AECMA (The European Association of Aerospace Industries). It is published on green paper for the needs of AECMA-Members. It has been technically approved by the experts of the concern
5、ed 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 interchangeability is affected, physically or functionally, without re-identification of the standard. After examination a
6、nd signature of the AECMA Standard Checking Centre INPS) and formal agreement of the Official Services of the Member countries it will be submitted as a draft European Standard to CEN (European Committee for Standardization) for formal vote. Nota - Extra copies can be supplied by B.N.A.E. - Technopo
7、lis 54 - 199, rue Jean-Jacques Rousseau - 921 38 ISCY-LEC-MOULINEAUX CEDEX STD-AECMA PREN 2877-ENGL 1997 1012311 0012L32 4T9 Page 3 prEN 2899: 1997 1 Scope This standard defines tests on the susceptibility to corrosion in a damp atmosphere of metals in contact with vulcanized rubbers. 2 Normative re
8、ferences IS0 471 Rubber - Standard temperatures, humidities and times for the conditioning and testing of test pieces EN 2071 Aerospace series - Sheets in aluminium and aluminium alloys - Thickness a I 6 mm - Dimensions 1) EN 2217 Aerospace series - Steel FE-PL52S - 1 080 MPa 5 Rm 5 1 250 MPa - Shee
9、ts and plates 2 mm I a I 20 mm 1) EN 2395 Aerospace series - Aluminium alloy AL-P2014A - T4 or T42 - Sheet and strip 0,4 mm I a I6 mm2) EN 2589 Aerospace series - Sheet and strip, cold rolled - Thickness 0,l mm I a 5 3 mm - Dimensions 2) 3 Definitions For the purposes of this standard, the following
10、 definition applies : Contact corrosion : The visually perceptible deterioration of the metal surface in contact with rubbers, after exposure in a damp atmosphere. 4 Principle The rubber test pieces shall be directly placed after immersion in the test fluid between two test metal disks and exposed t
11、o a damp atmosphere under defined conditions. After exposure, the metal disks shall be visually examined so that deterioration due to corrosion can be noted. 5 Apparatus and auxiliary products 5.1 Apparatus - test assembly which enables a compression of (12 f 3) % of the rubber test pieces by means
12、of metal disks (figure 1) ; - a device for producing x 20 magnification ; - climatic chamber where a relative humidity of 95 % minimum can be obtained at (23 - appropriate solvent ; - lintfree cotton cloth ; - test fluids. 1) Published as AECMA Standard at the date of publication of this standard 2)
13、 Published as AECMA Prestandard at the date of publication of this standard Previous page is blank 6 Specimens 6.1 Metal disks 6.1 -1 Material Type 1 - Aluminium alloy AL-PaO14A - T4 or T42 according to EN 2395. Type 2 - Steel FE-PL52S - 1 080 MPa I R, I 1 250 MPa according to EN 2217. 6.1.2 Dimensi
14、ons The metal to be tested shall be circular disks of an outer diameter (120 f 0,5) mm, with a (20 + :I2) mm diameter hole in the centre (see figure 1). These disks shall be 5 mm thick minimum if they are in steel and 10 mm minimum thick if they are in aluminium so that they are not deformed when gr
15、ipped. 6.1.3 Preparation The metal disks shall have a roughness of 0,4 pm maximum on all surfaces. The edges shall be rounded. 6.1.4 Number For each test and exposure method, use two metal disks. The two disks may be made of the same metal or of two different metals. 6.2 Rubber test pieces 6.2.1 Mat
16、erial According to the material standard. 6.2.2 Dimensions (20 f 1) mm x (20 11 1) mm cut from test strips (2 11 0,2) mm thick. 6.2.3 Number Three test pieces for each test and exposure method. 6.2.4 The test pieces shall be stored according to IS0 471. Time lapse between vulcanization and testing 7
17、 Test conditions 7.1 Test temperature The temperature shall be (23 f 2) OC. 7.2 Testing time The testing time shall be 7 d or a multiple of 7 d. STD-AECMA PREN 2899-ENGL 1977 m 1012311 001213Li 271 W Page 5 prEN 2899: 1997 7.3 Humidity The relative humidity shall be 95 % minimum. 8 Procedure Clean a
18、ll the surfaces of the metallic disks and the rubber test pieces with a lintfree cotton cloth soaked in an appropriate solvent and leave to dry for 2 h minimum at (23 f 2) OC. After cleaning, the degreased test pieces shall not be touched with bare fingers ; they shall only be handled with polyethyl
19、ene gloves. Depending on the method chosen, the rubber test pieces and the metallic disks shall be conditioned as follows : I!m - batch and date of manufacture ; - material of metal disks ; - test environment ; - exposure time ; - number of tests ; - visible deteriorations of the metal disks/descrip
20、tion of corrosion ; - any detail not provided for this standard or the subject of specific requirements ; - test date. STD-AECMA PREN 2899-ENGL 1997 1012311 001213b 044 = Page 7 prEN 2899: 1997 Dimensions in millimetres Section A-A Section B-B Figure 1 : Example of test assembly (metallic disks of the same material)
