ImageVerifierCode 换一换
格式:PDF , 页数:3 ,大小:69.22KB ,
资源ID:466174      下载积分:10000 积分
快捷下载
登录下载
邮箱/手机:
温馨提示:
如需开发票,请勿充值!快捷下载时,用户名和密码都是您填写的邮箱或者手机号,方便查询和重复下载(系统自动生成)。
如填写123,账号就是123,密码也是123。
特别说明:
请自助下载,系统不会自动发送文件的哦; 如果您已付费,想二次下载,请登录后访问:我的下载记录
支付方式: 支付宝扫码支付 微信扫码支付   
注意:如需开发票,请勿充值!
验证码:   换一换

加入VIP,免费下载
 

温馨提示:由于个人手机设置不同,如果发现不能下载,请复制以下地址【http://www.mydoc123.com/d-466174.html】到电脑端继续下载(重复下载不扣费)。

已注册用户请登录:
账号:
密码:
验证码:   换一换
  忘记密码?
三方登录: 微信登录  

下载须知

1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。
2: 试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓。
3: 文件的所有权益归上传用户所有。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 本站仅提供交流平台,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

版权提示 | 免责声明

本文(ASTM C282-1999(2005) Standard Test Method for Acid Resistance of Porcelain Enamels (Citric Acid Spot Test)《搪瓷耐酸的标准试验方法(柠檬酸斑点试验)》.pdf)为本站会员(diecharacter305)主动上传,麦多课文库仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知麦多课文库(发送邮件至master@mydoc123.com或直接QQ联系客服),我们立即给予删除!

ASTM C282-1999(2005) Standard Test Method for Acid Resistance of Porcelain Enamels (Citric Acid Spot Test)《搪瓷耐酸的标准试验方法(柠檬酸斑点试验)》.pdf

1、Designation: C 282 99 (Reapproved 2005)Standard Test Method forAcid Resistance of Porcelain Enamels(Citric Acid Spot Test)1This standard is issued under the fixed designation C 282; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t

2、he year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers a

3、 procedure for evaluatingporcelain enamels in their resistance to citric acid exposure atroom temperature. No attempt is made to categorize porcelainenamels as to their acid-resistance or non acid-resistanceproperties, since the requirements in the several branches of theindustry differ.1.2 The test

4、 method is applicable for ware of various shapesproviding they contain a substantially flat area approximately50 mm in diameter.1.3 The test method is not applicable to finishes on chemicaland hospital ware, which may come in contact with strongmineral acids, nor to cooking utensils, which may come

5、inprolonged contact with hot acid solutions.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulat

6、ory limitations prior to use.2. Summary of Test Method2.1 The test method consists of a 15 min exposure of the testsurface to a small pool of 10 % citric acid, and an evaluation ofthe effect in terms of the change in appearance and the “relativecleanability” of the surface resulting from the treatme

7、nt.3. Significance and Use3.1 This test method is intended specifically for testing theporcelain enamel finish on stoves, refrigerators, table tops,sinks and other sanitary ware, laundry appliances, architecturalunits, etc., where the surface may come in contact with foodacids at room temperature.3.

8、2 Citric acid has been chosen as the test medium becauseit is one of the most common of the food acids and willgenerally provide a measurable result in its action on porcelainenamel.4. Apparatus4.1 Dropper Bottle, or medicine dropper,4.2 Watch Glass, 25 mm in diameter with fire polished edge,4.3 Tow

9、el, soft cotton, and4.4 Drafting Pencil, conventional graphite, degree 3B.5. Reagents and Materials5.1 Citric Acid SolutionDissolve 10 g of anhydrous citricacid crystals (H3C6H5O7) in 100 mL of water. Solution shall beprepared not more than 48 h prior to use.5.2 Cleaner SolutionDissolve 10 g of tris

10、odium phos-phate (Na3PO4) in 1 L of tap water.6. Sampling6.1 The test specimens may be articles of commerce, piecescut from articles of commerce, or laboratory specimens pre-pared especially for this test.NOTE 1Processing variables in the application and drying and firingoperations materially affect

11、 the degree of attack by the acid on the surfaceof porcelain enamels. Sample specimens used for classification of acidresistance must be processed under identical conditions to the commercialware they represent.7. Procedure7.1 Thoroughly wash area to be tested using a soft cottontowel moistened with

12、 a warm, 1 % solution of trisodiumphosphate. Rinse in warm, running tap water, and dry with asoft towel by blotting. Store the specimen at a temperature of26 6 1C (79 6 2F) for a time sufficient to bring it within thisrange prior to and during the test.NOTE 2If, when rinsing, the water gathers in dr

13、ops on the surface,repeat washing treatment until water spreads evenly.7.2 On articles of commerce, select areas that are horizontalor nearly horizontal in service. Place the specimen in a positionsuch that a flat area at least 38.1 mm in diameter is horizontal.1This test method is under the jurisdi

14、ction ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.12 onMaterials for Porcelain Enamel and Ceramic-Metal Systems.Current edition approved Sept. 15, 2005. Published September 2005. Originallyapproved in 1951. Last previous edition approve

15、d in 1999 as C 282 99.This test method is based on the Test for Acid Resistance of Porcelain Enamels(Citric Acid Spot Test) Bulletin T-21, of the Porcelain Enamel Institute.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.With the spe

16、cimen and the citric acid solution at 26 6 1C (796 2F), place several drops of the solution on the test area toform a pool, and immediately cover with a clean watch glass inthe inverted position. Use a quantity of solution that is justsufficient to fill the inverted watch glass except for a small ai

17、rbubble (three to six drops are usually required, depending uponthe dropper and the curvature of the watch glass). After 15 minof treatment, remove the watch glass and immediately rinse thespot of solution from the surface. Dry the specimen with a dry,clean, soft cotton towel by blotting (not rubbin

18、g).NOTE 3The test surface must be thoroughly dry before grading. Thepresence of a slight film of water on the surface may change the rating ofspecimens near the borderline between classes.8. Grading8.1 Grade the test specimen within 2 h after exposure to thetest solution using the procedure outlined

19、 in the diagram, Fig.1. Rate each specimen with the appropriate classification grade,AA, A, B, C or D, as explained in Table 1. The criteria referredto in Fig. 1 and Table 1 are described as follows:8.1.1 Visual ExaminationView the specimen at variousangles with respect to the light source and eye,

20、in order todetect whether the “treated area” differs in any respect from the“protected area.” Use partially diffused daylight, supplementedif necessary by artificial light, the total intensity being approxi-mately that available within a few feet of an outside window,but do not examine in direct sun

21、light. During observation, holdthe specimen no nearer the light source (such as a window)than the minimum diameter of the source.NOTE 4The term “treated area” refers to that portion of the specimenwhich has been subjected to acid solution confined by the watch glassduring treatment. The term “protec

22、ted (untreated) area” refers to the areaadjacent to the treated area.NOTE 5Some colored porcelain enamels exhibit a change in color asa result of the acid treatment. Since the test is designed primarily toevaluate durability, color changes as revealed by this test should beignored except where other

23、wise specified.8.1.2 Dry-Rubbing TestUsing the flat point of a degree3B, conventional graphite drafting pencil held in a normalwriting position and applied with firm pressure, draw two ormore approximately parallel lines extending across the treatedarea. Starting with gentle pressure and then applyi

24、ng graduallyincreasing pressure, rub repeatedly across the lines with a dry,clean, soft cotton towel as illustrated in Fig. 2. If marks arecompletely removed from the treated area, the specimen shallbe rated as Class AA. Otherwise, continue as directed.NOTE 6The pencil point should be prepared by ho

25、lding a sharpenedpencil in a normal writing position and rubbing on abrasive paper (1/0Emery polishing or 400-grit silicon carbide or aluminum oxide abrasivepaper) until the minimum diameter of the flat, circular cross section is halfthat of the full graphite core.8.1.3 Blurring-Highlight TestIn a w

26、ell-lighted location,hold the specimen so that the image of a small light source,such as a frosted lamp bulb, is observed as a highlight in theprotected area, the line of vision being within 45 perpendicu-lar to the surface (a desk lamp with an incandescent bulb isrecommended for this purpose). Focu

27、s the eyes on the image ofthe light source, then slowly shift the specimen just sufficientlyto bring this image into the treated area observing it as it passesacross the boundary line between the two areas. Ignore anycolor difference in the enamel due to staining. If a definiteblurring of the image

28、is observed as it passes from theprotected to the treated area, the specimen shall be rated asClass C or Class D. Proceed to 8.1.5 to determine finalclassification. If a blurring image is not observed, the specimenshall be rated as Class A or Class B. Proceed to 8.1.4 todetermine final classificatio

29、n.8.1.4 Wet-Rubbing TestUsing the procedure specified in8.1.2 mark the treated area and rub the marks with a clean, softcotton towel which has been dipped in water and twisted toremove any excess. For this test, make new marks in a locationFIG. 1 Flow Sheet of Test Procedure for Classification of Tr

30、eated SpecimensTABLE 1 Requirements for Respective Classes of AcidResistanceClassification RequirementsClass AA No visible stain, andPass dry-rubbing testClass A Pass blurring-highlight test, andPass wet-rubbing testClass B Pass blurring-highlight test, andFail wet-rubbing testClass C Fail blurring-

31、highlight test, andPass disappearing-highlight testClass D Fail disappearing-highlight testC 282 99 (2005)2other than that used for the dry-rubbing test. Do not use soap,abrasive, or similar cleaning material. If the marks are com-pletely removed from treated area, the specimen shall be ratedas Clas

32、s A. Otherwise it shall be rated as Class B.8.1.5 Disappearing-Highlight TestThis test is similar inall respects to the blurring-highlight test specified in 8.1.3,except that the criterion in this case is the complete disappear-ance of the highlight in the treated area. If the highlight isvisible in

33、 the treated area, the specimen shall be rated as ClassC. If the highlight disappears in the treated area, the specimenshall be rated as Class D.9. Report9.1 Report the assigned grade for each specimen. If thecitric acid treatment is performed at temperatures outside thestated tolerances, this varia

34、tion should be reported.10. Reproducibility10.1 Since variations may occur during enameling whichaffect the acid resistance, several specimens should be treatedto determine the class of commercial ware.10.2 Ratings of individual specimens shall be considered asdue to actual differences in the acid r

35、esistance of the speci-mens, not to differences in the test procedure.11. Precision and Bias11.1 The precision and bias of this test method is beingestablished.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this stan

36、dard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be revie

37、wed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsibl

38、e technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Con

39、shohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).FIG. 2 Method of Applying and Rubbing Pencil Marks on theTreated AreaC 282 99 (2005)3

copyright@ 2008-2019 麦多课文库(www.mydoc123.com)网站版权所有
备案/许可证编号:苏ICP备17064731号-1