1、Designation: B183 79 (Reapproved 2014)B183 18Standard Practice forPreparation of Low-Carbon Steel for Electroplating1This standard is issued under the fixed designation B183; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This practice is intended as
3、 an aid to electroplaters in setting up a suitable cleaning cycle preparatory to electroplating oflow-carbon steel (Note 1) containing less than 0.35 mass % of carbon and to indicate some of the precautions that must be takento maintain this cycle in good operating condition.NOTE 1The preparation of
4、 high-carbon steel for electroplating is covered in Guide B242.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It i
5、s the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized princip
6、les on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2B242 Guide for Preparation of High-C
7、arbon Steel for ElectroplatingB322 Guide for Cleaning Metals Prior to Electroplating3. Nature of Cleaning3.1 The preparation of low-carbon steel for electroplating involves three basic steps in the following order:3.1.1 Removal of oil, grease, and caked-on dirt,3.1.2 Removal of scale and oxide films
8、 by “pickling,” and3.1.3 Removal of any smut left on the surface after step 3.1.2 and activation of the steel.3.2 Removal from the steel of fabricating lubricants and finishing compounds may have to be undertaken by “precleaning”before the articles reach the electroplating room. The remainder of the
9、 operations should immediately precede the electroplating.In some instances separate removal of smut may not be necessary as in the case of parts which are barrel-electroplated and tumbled.4. Cleaning Solutions and Apparatus4.1 All solutions should be subject to chemical control, including determina
10、tions of the free acid and iron contents of thepickling solutions and acid dips, and such tests of the cleaning solutions as recommended by the manufacturer.4.2 Based on tests and experience, all solutions should be discarded before they have lost their effectiveness.4.3 To conserve cleaning and pic
11、kling solutions and to ensure continuous operation when heavy production is involved,doubling of facilities in the same line of operation may be desirable. This arrangement will result in a high degree of contaminationof the first of two solutions of the same kind while the second ones will be suffi
12、ciently clean to continue to use. It will also reducethe degree of contamination of subsequent solutions, for example, by oil and grease.1 This practice is under the jurisdiction of ASTM Committee B08 on Metallic and Inorganic Coatingsand is the direct responsibility of Subcommittee B08.02 on PreTre
13、atment.Current edition approved Nov. 1, 2014June 1, 2018. Published November 2014June 2018. Originally approved in 1943. Last previous edition approved in 20092014 asB183 79(2009). DOI: 10.1520/B0183-79R14.14. DOI: 10.1520/B0183-18.2 For referencedASTM standards, visit theASTM website, www.astm.org,
14、 or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes
15、have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official
16、document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.4 As an alternative to the procedure described in 4.3, the cleaner and pickle tanks may be provided with a large dam overflowand a pump having its intake placed about half-way
17、 down the overflow dam between the accumulated grease and oil on top andthe settled-out solid dirt at the bottom, and having its outlet placed near the bottom of the tank at the end opposite to the damoverflow.4.5 Separate tank electrodes, removable from the tank for inspection and cleaning, should
18、be used. Contact hooks for theelectrodes should be of the inverted V-type for round tank bars and should be of sufficient size to carry the required current.4.6 Rinse tanks should be arranged with a dam overflow, and any water inlet other than a spray should be placed so as to ensurethorough circula
19、tion of the water and a large working surface free from grease accumulation. An adequate flow of water isessential.4.7 Heating coils should be placed on the work-piece side of the tank in order to assure a working surface free from greaseaccumulation.5. Procedure for Racked Parts5.1 The cycle descri
20、bed in 5.2 to 5.6 should be used for the preparation of racked parts subsequently electroplated in still tanks,agitated tanks, semi- and full-automatic equipment, except in those cases described in Section 6.5.2 PrecleaningIn general, it is necessary to remove fabricating lubricants, buffing compoun
21、ds, and other soils by precleaning.This precleaning may be accomplished with alkaline soak cleaners, cleaners designed to remove buffing compounds (including theuse of ultrasonic cleaners), alkaline spray cleaners, and the use of chlorinated solvents such as trichloroethylene andperchloroethylene in
22、 vapor-type degreasing equipment, or by use of cold chlorinated solvents if vapor equipment is not available.Precleaning normally should be accomplished as soon as possible after fabrication because many stamping lubricants and buffingcompounds become much more difficult to remove if allowed to age
23、on the steel surface and can chemically attack the substratecausing etching.5.3 ElectrocleaningThe part to be cleaned should be anodically (reverse) electrocleaned in a solution of a suitablycompounded, free-rinsing, high-conductivity steel electrocleaner, at a concentration of about 45 to 90 g/L. T
24、he current densityshould preferably be between 5 and 6 A/dm2 and the tank voltage about 6 V. The temperature should be between 60 and 90C.The time of cleaning following an effective precleaning operation is usually between 1 and 4 min. If proprietary cleaners are used,the recommendations of the manu
25、facturer should be followed.5.4 Water RinseImmerse the part to be cleaned in clean, overflowing water for a minimum of 15 s. If possible, air agitationof the water rinse should be provided. If the water is very cold, below 10C, slight warming is beneficial. A fresh water spray onthe part as it enter
26、s and leaves the rinse tank helps ensure complete rinsing.5.5 Acid PicklingPickle the part in a solution of 150 to 500 mL of concentrated, 31 mass %, hydrochloric acid (density 1.16g/mL) diluted to 1 L, 100 mL of concentrated, 93 mass %, sulfuric acid (density 1.83 g/L)g/mL) diluted to 1 L, or a sol
27、ution ofproprietary acid salts at room temperature, for a sufficient length of time to remove all oxides, rust, or scale. (Warning The acidshould be added to the approximate amount of water required and then after thorough mixing, diluted to exact volume.)5.6 Alkaline DescalingIn place of acid pickl
28、ing (5.5) it is sometimes found that alkaline descaling may be more practical.Such solutions are operated at about 40C and average current density of 2 to 5 A/dm2 . A typical bath composition may be asfollows:Sodium hydroxideSodium cyanideChelating agent180 g /L120 g/L(EDTA-NTA gluconates) 80 g/LWhe
29、n using this method it must be followed by a water rinse (5.4), an acid dip (5.5), and water rinse (5.4).5.7 Water RinseRinse the part again, as described in 5.4 but in a separate tank.6. Variations in Procedure for Racked Parts6.1 Consideration should be given to separate precleaning between manufa
30、cturing operations; for example, betweengear-cutting and deburring operations, and between drawing or stamping and buffing operations.6.2 Vapor phase degreasing with chlorinated solvents is an excellent way to remove mineral oil form recesses such asoverlapping joints that cannot be cleaned by any o
31、ther method.6.3 Plants with limited facilities sometimes omit precleaning especially with work that is not too heavily soiled. This ispermissible; however, electrocleaning time may have to be increased and it is almost always necessary to change electro-cleanersmore frequently. Likewise, close contr
32、ol is necessary to ensure proper electrocleaner concentration at all times.6.4 While pickling in strong hydrochloric acid or acid salts in accordance with 5.5 is suitable for most oxide conditions,including heavy annealing scale, welding marks, or wheel burns, it may sometimes be preferable to use h
33、ot sulfuric acid (about100 mL of concentrated, 93 mass %, sulfuric acid (density 1.83 g/mL) diluted to 1 L) containing a suitable inhibitor to protect theB183 182steel from over pickling (see Warning in 5.5). The acid temperature may vary between 50 and 70C. When inhibitors are used,a second alkalin
34、e cleaning operation, preferably electrocleaning, should follow pickling to remove any adsorbed inhibitor.6.5 Heavy scale may be removed more rapidly by making the part to be pickled either anodic or cathodic in a 50 to 100 mLof concentrated, 93 mass %, sulfuric acid (density 1.83 g/mL) diluted to 1
35、 L or proprietary acid salt solution at a temperature of50 to 65C and an average current density of about 4A/dm2 (see Warning in 5.5).Anodic pickling avoids hydrogen embrittlement.Cathodic pickling provides a brighter surface provided the acid is not contaminated with heavy metals such as copper, ti
36、n or lead.6.6 In addition to acid pickling, scale may be removed by shot-blasting, tumbling, or sandblasting. These methods avoidhydrogen embrittlement but may work-harden the surface.6.7 When there is a lapse of time between the final rinsing operation (5.6) of the preparatory cleaning process and
37、electroplating,arrangements should be made for temporary storage of parts. Those which are to be electroplated in a cyanide solution may bestored in a solution of 15 to 30 g/Lof sodium cyanide and an equal amount of sodium hydroxide at room temperature. Those whichare to be electroplated in an alkal
38、ine solution such as alkaline tin, should be stored in a solution containing 8 g/L of sodiumhydroxide at room temperature. Storage time for parts to be nickel electroplated should be minimized but, if necessary, they maybe held in clean cold water for a very short time (3 or 4 min, depending on wate
39、r quality).7. Procedure for Parts in Bulk7.1 The cycle described in 7.2 to 7.5 should be used for cleaning part to be electroplated in barrels, hand-operated or automatic,except in those cases described in Section 8.7.2 Alkaline CleaningClean the parts by tumbling with or without current, in a solut
40、ion of 30 to 60 g/L of a suitable alkalinecleaner at 60 to 90C. Anodic electrocleaning at about 2 to 4 A/dm2 may supplement tumbling for more effective cleaning.7.3 Water RinseRinse the parts in clean, overflowing water. Air agitation of the rinse water is beneficial. If the water is verycold, rinsi
41、ng is improved by some warming.7.4 Acid PicklingPickle in a solution of 150 to 500 mL of concentrated, 31 mass %, hydrochloric acid (density 1.16 g/mL)diluted to 1 L at room temperature. Other suitable pickling solutions are proprietary acid salts and 50 to 150 mL of concentrated,93 mass %, sulfuric
42、 acid (density 1.83 g/mL) diluted to 1 L (see Warning in 5.5).7.5 Water RinseRinse the parts again as described in 7.3, using a separate tank.8. Variations in Procedure for Bulk Parts8.1 Two water rinses after both cleaning and acid pickling are beneficial in many barrel electroplating operations. T
43、his servesto ensure more complete rinsing and thus prevent carry-over of cleaners or acids into subsequent tanks.8.2 Heavily scaled parts such as heat-treated nuts and bolts may require pickling in strong inhibited sulfuric acid (see 6.4).Tumble-pickling is preferred to immersion-pickling in bulk be
44、cause the tumbling action increases the rate of scale and oxideremoval.8.3 StorageIf parts must be stored after cleaning and pickling prior to electroplating, the procedure described in 6.7 shouldbe followed.NOTE 2Additional information on procedures for cleaning of low-carbon steel prior to electro
45、plating may be found in Guide B322.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
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