1、Petroleum products and lubricants Determination of rust-preventing characteristics in the presence of water (IS0 7120 : 1987) Petroleum oils and other fluids ICs 75.080 Supersedes DIN 51585, December 1971 edition. Minerallerzeugnisse und Schmierstoffe - Mineralle und andere Flssigkeiten - Bestimmung
2、 der Korrosionsschutzeigenschaften in Gegenwart von Wasser (IS0 71 20 : 1987) DIN IS0 7120 This standard incorporates International Standard IS0 7120 Petroleum products and lubricants - Petroleum oils and other fluids - Determination of rust- preventing characteristics in the presence of water. A co
3、mma is used as the decimal marker. National foreword This standard has been prepared by ISO/TC 28. The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Technical Committee Prfung von Schmierlen, sonstigen len und Para
4、ffinen. DIN EN IS0 31 70 and DIN 51 51 9 are the standards corresponding to International Standards IS0 31 70 and IS0 3448, respectively, referred to in clause 2 of the IS0 Standard. Amendments DIN 51 585, December 1971 edition, has been superseded by the specifications of DIN IS0 71 20. Previous ed
5、itions DIN 51585: 1962-10, 1971-12. National Annex NA Standards referred to (and not included in References) DIN 51519 IS0 viscosity classification for industrial liquid lubricants DIN EN IS0 31 70 Petroleum liquids - Manual sampling (IS0 31 70 : 1988 + Al : 1998) IS0 Standard comprises 11 pages. No
6、 part of this standard may be reproduced without the prior permission of Ref. No. DIN IS0 7120 : 2000-05 IN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany, as the exclusive right of sale for German Standards (DIN-Nonen). English price group O9 Sales No. 0409 09
7、.00 Page 1 IS0 71 20 : 1987 Petroleum products and lubricants Determination of rust-preventing characteristics in the presence of water Petroleum oils and other fluids Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member
8、 bodies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- ment
9、al and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. They are approved in accordance with IS0
10、 procedures requiring at least 75 % approval by the member bodies voting. International Standard IS0 7120 was prepared by Technical Committee ISO/TC 28, Petroleum oroducts and lubricants. Users should note that all International Standards undergo revision from time to time and that any reference mad
11、e herein to any other International Standard implies its latest edition, unless otherwise stated. Page 2 IS0 7120 : 1987 1 Scope and field of application 1.1 This International Standard specifies a method for evaluating petroleum oils and other fluids to indicate their effectiveness in preventing th
12、e rusting of ferrous parts should water become mixed with the oil/fluid. The method is for application to inhibited mineral oils including steam turbine oils, circulating oils and hydraulic oils and non-hydrocarbon fluids including fluids denser than water. 1.2 In many cases, such as in the gears of
13、 a steam-turbine, water can become mixed with the lubricant, and rusting of ferrous parts may occur. This test indicates the effectiveness of inhibited mineral oils aid in preventing this type of rusting. 2 References IS0 3170, Petroleum products - Liquid hydrocarbons - Manual sampling. IS0 3171, Pe
14、troleum products - Liquid hydrocarbons - Automatic pipeline sampling. IS0 3448, Industrial liquid lubricants - IS0 viscosity classi- fication. 3 Principle A mixture of 300 ml of the oil or fluid under test is stirred with 30 ml of distilled water or synthetic sea water, as required, at a temperature
15、 of 60 OC with a cylindrical steel specimen com- pletely immersed therein. It is customary to run the test for 24 h; however, the test period may, at the discretion of the interested parties, be for a shorter or longer period. The specimen is then observed for signs of rusting and degree of rusting.
16、 4 Reagents and materials Unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 4.1 Cleaning and polishing fluid, iso-octane. NOTE - For non-reference testing, petroleum spirit of satisfactory volatility may be used. CAUTION
17、 - /so-octane is flammable. Do not use in an area near sparks or an open flame. Provide adequate ven- tilation. 4.2 Chromic acid cleaning solution or other equally effective glassware cleaning fluid. CAUTION - Chromic acid is a highly corrosive and toxic substance. For environmental and/or toxicolog
18、ical reasons, its use is forbidden in many laboratories. In this case, use an alternative cleaning fluid which has been shown to produce chemically clean glassware. Prepare chromic acid cleaning solution by dissolving 400 g of sodium dichromate (Na2Cr207) in 100 ml of hot water. Allow the solution t
19、o cool and store in a glass-stoppered bottle. Place 35 ml of this saturated sodium dichromate solution in a 1 500 ml beaker. In a fume hood, while stirring, carefully add 1 litre of sulfuric acid iH2SO4). Stir for 5 min. Store in a glass- stoppered bottle. 4.3 Distilled water. 4.4 Synthetic sea wate
20、r, for testing in accordance with procedure B, and conforming to the requirements given in 9.1 and 9.2. 4.5 Steel test specimen, as described in 7.1. 5 Apparatus 5.1 Oil bath, thermostatically controlled and capable of maintaining the test sample at a temperature of 60 f 1 OC. An oil of viscosity gr
21、ade IS0 VG 32 is suitable for the bath. The bath shall have a cover with holes to accommodate the test beakers. 5.2 Thermometer, for checking the temperature of the test fluid with scale divisions of 0,5 OC with a specified immersion specification to allow measurement of the temperature in the test
22、vessel at 60 OC with a precision at least equal to that of thermometer STL/0,5/ -351 + 115 of IS0 653. NOTE - Thermometer conforming to ASTM 9C/IP 15C or ASTM 34ClIP 21c. Page 3 IS0 71 20 : 1987 5.3 Beaker, 400 ml, tall-form heat-resistant borosilicate glass without pourout, as shown in figure 1, ap
23、proximately 127 mm in height measured from the inside bottom centre and approxi- mately 70 mm in inside diameter measured at the middle. 5.4 Beaker cover, flat, as shown in figure 2, of glass polymethyl methacrylate (PMMA) or chlorotrifluorethylene, kept in position by suitable means such as a rim o
24、r groove. Two holes shall be provided on any diameter of the cover; one for a stirrer approximately 12,O mm in diameter with its centre approximately 6.4 mm from the centre of the cover; and the other, on the opposite side of the centre of the cover, for the test specimen assembly (see clause 7). ap
25、proximately 18 mm in diameter with its centre approximately 16 mm from the centre of the cover. In addition, a third hole 12 mm in diameter shall be provided for a thermometer with its centre approximately 22 mm from the centre of the cover and on a diameter of the cover at right angles to the diame
26、ter through the other two holes. (Tolerances with respect to the dimensions are given in figure 2.) NOTE - An inverted Petri dish makes a suitable cover, as the sides of the dish aid in keeping it in position. Figure 2 shows a PMMA cover for the beaker which has been found to be suitable. An optiona
27、l feature is shown, consisting of a slot, 1,6 mm by27,O mm, which is centred on a diameter of the stirrer hole at right angles to the cover diameter through the specimen hole and stirrer hole. This feature allows withdrawal of the stirrer while the beaker cover is in place. If the test is used for o
28、ther fluids such as synthetics, the beaker cover should be made from chemically resistant materials such as polychlorotrifluoro- ethylene) (PCTFE) and chlorotrifluoroethylene. 5.5 Stirrer, constructed entirely from 18/8 chromium nickel stainless steel in the form of an inverted T. A flat blade 25 f
29、1,0 mm x 6 f 0,5 mm x 0,6 I 0,l mmshall beattach- ed to a 6 mm rod in such a way that the blade is symmetrical with the rod and has its flat surface in the vertical plane. NOTE - If stainless steel is not obtainable, stirrers made of heat- resistant borosilicate glass and having the same dimensions
30、as the stainless steel stirrers specified rnay be used. 5.6 maintaining a speed of 1 O00 f 50 r/min. Stirring apparatus, any convenient form, capable of 5.7 Grinding and polishing equipment. 5.7.1 Abrasive cloth, metalworking aluminum oxide, 97 pm and 53 pm (see the note) closed coat on a jeans back
31、ing. NOTE - The corresponding grit sizes differ in Europe and the USA, the corresponding values being 280 grit and 240 grit respectively. A corresponding difference does not arise in respect of 150 grit. 5.7.2 Chuck, suitable for holding the specimen (see figure 4). 5.7.3 speed of 1 700 to 1 800 r/m
32、in. Rotation device, capable of rotating the specimen at a 5.8 Specimen assembly, as described in 7.1. 5.9 Oven, capable of maintaining a temperature of 64 f 1 oc. 6 Sampling Take a representative sample of the product to be tested ac- cording to IS0 3170 or IS0 3171 (or other relevant method). 7 Te
33、st specimen and its preparation 7.1 Requirements The specimen assembly (5.8) shall consist of a round steel specimen fitted to a plastic holder. The plastic holder shall be made of PMMA resin in accordance with the dimensions shown in figure 3 (two types of holders are illustrated). When testing non
34、-hydrocarbon fluids, the plastic holder should be made from chemically resistant material such as polytetra- fluoroethylene (PTFE). The round steel specimen when new shall be 12 to 13 mm in diameter and approximately 68 mm in length exclusive of the threaded portion which screws into the plastic hol
35、der and shall be tapered at one end as shown in figure 3. It shall be made of steel conforming to the specifi- cation given in annex A. If these steels are not available, other equivalent steels may be used, provided that they are found to be satisfactory by comparative test using this method. In ca
36、ses of dispute, steel corresponding to the specification (annex A) shall be used for reference testing. The steel specimen, either new or from a previous test, shall be prepared as described in 7.2 and 7.3. NOTE - When making a check test, the steel specimen that showed rust should not be re-used. S
37、pecimens that repeatedly show rust in tests of various oils may be imperfect. Such specimens should be used with oils known to pass the test. If rusting occurs in repeat tests, these specimens should be discarded. 7.2 Preliminary grinding If the specimen has been used previously and is free from rus
38、t or other irregularities, the preliminary grinding may be omitted, and the specimen rnay be subjected only to final polishing as prescribed in 7.3. If the specimen is new or if any part of its surface shows rust or other irregularities, clean it with cleaning solvent (4.1). Grind with 97 pm aluminu
39、m oxide cloth (5.7.1) to remove all ir- regularities, pits, and scratches, as determined by visual in- spection. The specimen shall not be touched with the hands at any stage after cleaning with ;so-octane (which precedes either preliminary grinding or final polishing) until the test is com- pleted.
40、 Forceps or a clean, lintless cloth may be used. This precaution also applies to specimens that are to be re-used. Perform the grinding by mounting the specimen in the chuck of the grinding and polishing apparatus, and turning it at a speed of 1 700 to 1 800 r/min while the 97 pm aluminium oxide clo
41、th (5.7.1 i is applied. Old 97 pm aluminum oxide cloth may be used to remove rust or major irregularities, but the grinding shall be completed with new cloth. Page 4 IS0 7120 : 1987 Proceed at once with the final polishing with 53 pm aluminum oxide cloth (5.7.1) or remove the specimen from the chuck
42、 and store in iso-octane until needed. Discard re-used specimens when the diameter is reduced to 10 mm. 7.3 Final polishing 7.3.1 Just before the test is to be made, subject the specimen to final polishing with 53 vm aluminum oxide cloth. If the preliminary grinding has just been completed, stop the
43、 motor which rotates the specimen. Otherwise, remove the specimen from the iso-octane (previously used unrusted specimens shall be stored in this reagent), dry with a clean cloth and place in the chuck. 7.3.2 Rub a new piece of 53 pm aluminum oxide cloth longitudinally over the static specimen until
44、 the rounded end and the entire surface show visible scratches. Rotate the specimen at a speed of 1 700 to 1 800 rimin and polish with a strip of 53 prn aluminum oxide cloth by wrapping it halfway around the specimen, and applying a firm but gentle downward pull to the loose ends of the cloth for ab
45、out 1 to 2 min so as to produce a uniform finely scratched surface free from longitudinal scratches. Carry out the final stages of the polishing with new cloth. NOTE - To ensure that the flat shoulder (that portion of the specimen perpendicular to the threaded stern) is free from rust, this area sho
46、uld be polished. This may be done by holding a strip of 53 um aluminum oxide cloth between the chuck and the shoulder while rotating the specimen for a brief period. 7.3.3 Remove the specimen from the chuck without touching with the fingers, wipe lightly with a clean, dry, lintless cloth or tissue (
47、or brush the specimen lightly with a camelhair brush), attach to the plastic holder, and immediately immerse in the oil to be tested. This may be either the hot test portion (8.1 or a clean test tube containing a portion of the sample. The specimen may be removed later from this tube and allowed to
48、drain briefly before being placed in the hot oil. 8 Procedure A for distilled water 8.1 The test shall be conducted in duplicate in order to report an oil as passing or failing. Clean the beaker (5.3) with chromic acid cleaning solution (4.2) or other equally effective glassware cleaning fluid (see
49、4.2, CAUTION), wash with distilled water to remove the acid completely. Dry in the oven (5.9). Clean a glass beaker cover (5.4) and a glass stirrer by the same procedure. To clean a stainless steel stirrer (5.5) and a PMMA cover (5.4). use cleaning solvent 4.1), wash thoroughly with hot water and finally with distilled water, and dry in the oven (5.9) at a temperature not over 65 OC. 8.2 Pour 300 ml of the oil to be tested into the beaker and place the beaker in the oil bath (5.1) held at a temperature that will maintain the test portion at a temperature of 60 f 1 OC. The beaker sh
