1、 ENGINEERING STANDARDS Test Procedure SUPERCEDED EDS-T-7427 Resistance to Scarping of Coating on Elastomer This standard may be applied only for current projects. It is Superceded for all future projects and replaced by GMW14125. ,hE+8 D9?i7 $4F !5H2e ?U9I - Note: 8 E:48t G8 =97 FF7 957%L+ , FG P-P
2、Program .Bd# GMW14125 ) $4=F7 957F$ . Copyright 2011 General Motors Company All Rights Reserved November 2011 Originating Department: GM Korea Engineering Standards Page 1 of 6 Version : 5 1 Scope Note: Nothing in this standard supersedes applicable laws and regulations. Note: In the event of confli
3、ct between the Korean and English language, the Korean language shall take precedence. 1.1 Purpose and Applicability. The purpose of this standard is to determine the adhesion and scraping resistance of coatings on elastomeric surface. For test pieces of coated elastomers, the resistance to scraping
4、 is determined in the as received condition and after treatment with specified test liquids. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. DIN 6784 2.2 GM Standards/Specifications. None 2.3 Additional Reference
5、s. None 3 Resources 3.1 Equipment. 3.1.1 Scraper. To be with half-round testing cutting edge and specified dimensions. The shape and dimensions shall be specified Figure 2. And in case of using a special scraper, it shall be specified on the part drawing a material specification. The shapes and dime
6、nsions of test scrapers shall be exactly observed in the area of the test cutting edge. All other dimensions may be varied as required. The width (X) of test scraper is as follows and the radius of test edges is X/2 in all cases. 1 P7 :0 : ., E:48 6&F !7$ :4-8! 9I8x $4=F 3L 6$ . :0 : F67t 7568 18 88
7、x 7 , F6* 72T8p) F$ . 1.1 +95 -C 957 -88 . ., E:48 +958t ,h.E E+8 D97 $4F 9E=2e -C !*+2e8x ?U9IFd 88F 4G -7 $4F 9IF$ . D9=*%P ,h4G D7 $4F 07 38%P E:48x 957F$ . 2.1 17 E:4 / . DIN 6784 2.2 GM E:4 / . None 2.3 dA E:4 / . None 3 4G 88 3.1 4G 8/x . 3.1.1 3A (D . -L GI8 4G 7 9 &%7 8F )72P =x?F+ GI10 A d#
8、 4G D0 :$4187 .H 9E=F 3L 8# 9I$7 6 F$ . 5H*# 2 25 mm 81 Fx7F$ . %P 4G D8x 984G .887 8 :%T 3L 8$) 7-L$47 7)X “#$ . 4G D8 :E672P 4G 8 :F%T 3L 8$) 88?* 8 9I4A$ . 4.2.2 3A (D4 $ * 3A (D 6 (Scraper Arm)7 * 7)X “ 4G :4/x1B) F$ . 8& 3A (D !8t $80 M8t F:E8 .0%P$ . & F:E (N) 1 5 2 10 3 -$ 9I GM KOREA ENGINEE
9、RING STANDARDS EDS-T-7427 Copyright 2011 General Motors Company All Rights Reserved November 2011 Page 3 of 6 Version : 5 4.2.3 The test carrier shall be moved by hand for 10 cycles unless otherwise specified in the engineering drawings or test specifications. The moving distance shall be at least 2
10、5 mm at a velocity of 50 mm/second. The test shall be performed towards from the direction of the blunt face of the scraper. 5 Data 5.1 Evaluation. Observation shall be made visually and the areas prior to 5 mm from where the test directions are reversed shall be ignored. After completion of the tes
11、t, no peeling of coatings shall occur on the elastomeric surface and the elastomeric base material shall not be visible through the coatings. 5.2 Expression of Results. The resistance to scraping of coatings on elastomers shall be evaluated according to the engineering drawings or material specifica
12、tions. The requirements shall be specified by the follow coding system. 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems associated with its use. It is the responsibility of the user of this standard
13、to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 7 Notes 7.1 Glossary. Resistance to Scraping: To be the ability of coatings to withstand the scraping by repeating action of a sharp edge. 7.2 Acronyms, Abbreviations, and Sym
14、bols. Not applicable. 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: 4.2.3 .E$+8! 8:7 -$8 9I8 6# F 4G D 7-L$4* 3L% 8p) 10 G -L.) , 8% 4A$ . 8& 8% *# 25 mm 81866 F+ 2$# 50 mm/ B: Slide Bars / 3(8& -H G: Scraper Arm / 3A (D 6 C: Sliding Mechanism / 3(
15、8& +?#: H: Support / :$4 D: Test Piece Holder / 4G D 9I$4 J: Pin with Masses / 9I7 Ft E: Scraper / 3A (D K: Balancing Mass / GI GM KOREA ENGINEERING STANDARDS EDS-T-7427 Copyright 2011 General Motors Company All Rights Reserved November 2011 Page 6 of 6 Figure 2: Scraper / ,* 2: 3A (D Material: Tool Steel. / 8: : Ch 3D, . Cutting Edge Hardness: HRc 60 62 / 9$ +2P* $ : HRc 60 62 Edge in the area of the test cutting edge to DIN 6784 / DIN 67847 &d( 4G 9$ +2P*8 +2P* . =* X = See clause 3.1.1 / X = 3.1.1F =l
