1、VOLVO Standard STD 423-0010Volvo GroupEstablished April 2004 Version 1 Page 13(13)Corrosion test in artificialatmospheres - salt spraytestsOrientationAs to its technical content this standard conforms toSS-ISO 9227:1990 Corrosion test in artificial atmospheres - Salt spray tests, and ASTM B 117 rega

2、rding NSS test and XP A 05-109.This standard is a further development of thepreviously issued standard STD 5711,102, issue 3.Contents 1 Scope and field of application 2 Test solutions 2.1 Preparation of the sodium chloride solution 2.2 pH adjustment 2.2.1 NSS test 2.2.2 AASS test 2.2.3 CASS test 2.3

3、 Filtration 3 Apparatus 3.1 Spray cabinet 3.2 Heater and temperature control 3.3 Spraying device 3.4 Collecting vessel 3.5 Re-use of apparatus 4 Method for evaluating the corrosivity of thechamber4.1 NSS test 4.1.1 Reference test pieces 4.1.2 Arrangement of the reference test pieces 4.1.3 Determinat

4、ion of mass loss 4.1.4 Checking of NSS apparatus operation 4.2 AASS test 4.2.1 Electrolytic coating 4.3 CASS test 4.3.1 Reference test pieces 4.3.2 Arrangement of the reference test pieces 4.3.3 Determination of mass loss (mass per unit area) 4.3.4 Checking of CASS apparatus operation 5 Test pieces

5、6 Arrangement of the test pieces 7 Operating conditions 8 Duration of test 9 Treatment of test pieces after test 10 Evaluation of results 11 Test report 人造氣氛腐蝕試驗鹽霧試驗目標本標準的技術內容與SS-ISO 9227:1990人造氣氛腐蝕試驗鹽霧試驗，ASTM B 117，XP A 05-109 相符合。本標準相對STD 5711,102而言有了更進一步的發展。目錄1 范圍和應用領域2 試驗溶液2.1氯化鈉溶液配制2.2 PH調整2.2.

6、1 NSS試驗（中性鹽霧試驗）2.2.2 AASS試驗（乙酸鹽霧試驗）2.2.3 CASS試驗（銅加速乙酸鹽霧試驗）2.3 過濾3 實驗設備3.1 噴霧箱3.2加熱系統3.3 噴霧裝置3.4 收集裝置3.5 再利用設備4 評價噴霧箱腐蝕性的方法4.1 NSS試驗（中性鹽霧試驗）4.1.1參照試樣4.1.2參照試樣的放置4.1.3測定質量損失4.1.4檢驗NSS裝置4.2 ASSS試驗（乙酸鹽霧試驗）4.2.1電解涂層4.3 CASS試驗（銅加速乙酸鹽霧試驗）4.3.1參照試樣4.3.2參照試樣的放置4.3.3測定質量損失（單位面積的質量）4.3.4檢驗CASS裝置5試樣6試樣放置7試驗條件8試

7、驗周期9試驗后試樣處理10 試驗結果評價11 試驗報告1 Scope and field of application This standard specifies the apparatus, the reagentsand the procedure to be used in conducting tests inneutral salt spray (NSS), acetic acid salt spray (AASS)and cupreous acetic acid salt spray (CASS) forassessment of the corrosion resistanc

8、e of metallicmaterials with or without permanent or temporarycorrosion protection.It also describes the method employed to evaluate thecorrosivity of the test cabinet environment.It does not specify the dimensions of the test pieces,the exposure period to be used for a particularproduct, or the inte

9、rpretation of results. Such detailsare provided in the appropriate product specifications.The salt spray tests are particularly useful for detectingdiscontinuities such as pores and other defects, andfor evaluating the corrosion resistance in certainmetallic, anodic oxide and conversion coatings.The

10、 neutral salt spray (NSS) test applies to: metals and their alloys certain metallic coatings (anodic and cathodic) certain conversion coatings certain anodic oxide coatings organic coatings on metallic materialsThe acetic acid salt spray (AASS) test is especiallyuseful for testing decorative coating

11、s of copper+nickel+chromium or nickel+chromium. It has also beenfound suitable for testing anodic oxide coatings onaluminium.The cupreous acetic acid salt spray (CASS) test isuseful for testing decorative coatings of copper+nickel+chromium or nickel+chromium. It has also beenfound suitable for testi

12、ng anodic coatings onaluminium.2 Test solutions 2.1 Preparation of the sodium chloridesolutionDissolve a sufficient mass of sodium chloride in distilledor deionized water with a conductivity notexceeding 20 S/cm at 25 C 2 C to produce aconcentration of 50 g/l 5 g/l. (The ratio is 95 partswater and 5

13、 parts sodium chloride.) The sodiumchloride concentration of the sprayed solutioncollected from the downfalling mist shall be 50 g/l 5 g/l. The density for a 50 g/l 5 g/l solution variesbetween 1,0255 and 1,0400 at 25 C.1 范圍和應用領域本 標 準規 定了中性鹽霧(NSS)，乙酸鹽霧(AASS)和銅加速乙酸欲霧(CASS)試驗使用的設備、試劑和方法。本標 準 也 規定了評估試驗

14、箱環境腐蝕性的方法。未規定試樣尺寸，特殊產品的試驗周期和結果解釋，這些內容參見相應的產品規范。本標準適用于評價金屬材料及覆蓋層的耐蝕性，被測試對象可以是具有永久性或暫時性防蝕性能的，也可以是不具有水久性或暫時性防蝕性能的。在中性鹽霧試驗中適用于 金屬及其合金 金屬覆蓋層 轉化膜 陽極氧化膜 有機覆蓋層乙酸鹽霧試驗適用于銅+鎳+鉻或鎳+鉻裝飾性鍍層，也適用于鋁的陽極氧化膜。銅加速乙酸鹽霧試驗適用于銅+鎳+鉻或鎳+鉻裝飾性鍍層，也適用于鋁的氧化膜。2 實驗溶液2.1 氯化鈉溶液配制將氯化鈉溶于電導率不超過20S/cm的蒸餾水或去離子水中，在25 C 2 C時濃度為50 g/l 5 g/l（該比率為

15、95份水和5部分氯化鈉）。氯化鈉的收集濃度在50 g/l 5 g/l。在25 C.時配制的溶液密度在 1.02551.0400范圍內。The sodium chloride shall contain less than 0,001 %(m/m) copper and less than 0,001 % (m/m) nickel asdetermined by atomic absorption spectrophotometry oranother analytical method of similar sensitivity. It mustnot contain more than 0

16、,1 % (m/m) sodium iodide ormore than 0,5 % (m/m) total impurities calculated fordry salt.NOTE - If the pH of the prepared solution, measuredat 25 C 2 C, is outside the range 6,0-7,0, thepresence of undesirable impurities in the salt and/orthe water shall be investigated.2.2 pH adjustment Adjust the

17、pH of the salt solution to the desired valueon the basis of the pH of the sprayed solution collected.2.2.1 NSS test Adjust the pH of the salt solution (2.1) so that the pHof the sprayed solution collected within the test cabinet(3.1) is between 6,5 and 7,2. Check the pH usingelectrometric measuremen

18、t at 25 C 2 C. In routinechecks, a short-range pH paper which can be read inincrements of 0,3 pH units or less can be used. Whenusing electrometric equipment wait until it is stable.Make any necessary correction by adding hydrochloricacid or sodium hydroxide solution of analytical grade.Possible cha

19、nges in pH may result from loss of carbondioxide from the solution when it is sprayed. Suchchanges may be avoided by reducing the carbon dioxide content of the solution by, for example, heating it to a temperature above 35 C before placing it in theapparatus, or by making the solution from freshlybo

20、iled water.2.2.2 AASS test Add a sufficient amount of glacial acetic acid to thesalt solution (2.1) to ensure that the pH of the solutioncollected in the test cabinet (3.1) is between 3,1 and3,3. If the pH of the solution initially prepared isbetween 3,0 and 3,1, the pH of the sprayed solution islik

21、ely to be within the specified limits. Check the pHusing electrometric measurement at 25 C 2 C, or,in routine checks, with a short-range pH paper whichcan be read in increments of 0,1 pH units or less.Make any necessary correction by adding glacialacetic acid or sodium hydroxide of analytical grade.

22、2.2.3 CASS test Dissolve a sufficient mass of copper(II) chloride dehydrate (CuCl2 2H2O) in the salt solution (2.1) to produce a concentration of 0,26 g/l 0,02 g/l equivalent to (0,205 0,015) g CuCl2 per litre.Adjust the pH using the procedures described in 2.2.2.氯化鈉應包含不少于0.001 (m/m)的銅和不少于0.001 (m/m

23、)的鎳所確定的原子吸收光譜法或其他類似靈敏度的分析方法。它絕不能含有超過0.1 (m/m)碘化鈉或0,5 (m/m)的總雜質干鹽。注意：如果調制溶液時，PH在25 C 2 C其值在6.07.0范圍外，則應存在不良雜質鹽，應對水進行調查。2.2PH調整根據收集的噴霧溶液的PH值調整鹽溶液倒規定的PH值。2.2.1 中性鹽霧試驗（NSS試驗）在噴霧箱（3.1）按（2.1）整配制的鹽溶液的PH值，使其在6.57.2之間。測量PH值可用酸度計在25C2C，也可用測量精度為0.3的PH試紙。PH值可用鹽酸或氫氧化鈉來調整.噴霧時溶液中二氧化碳損失可能導致PH變化，應采取辦法，例如將溶液加熱到超過35 C

24、再送進儀器或用新的沸騰水配制，以降低二氧化碳含量，可避免PH變化.2.2.2 乙酸鹽霧試驗（AASS試驗）按2.1配制的溶液中加入適量的冰乙酸保證噴霧箱內的PH值在3.13.3之間， 如剛配制的PH在3.03.1，則噴霧箱收集的PH一般在3.13.3范圍內。測量PH值可用酸度計在25 C 2 C，也可用測量精度為0.1的PH試紙，溶液的PH值可用冰乙酸或氫氧化鈉來調整。2.2.3 銅加速乙酸鹽霧試驗（CASS試驗）在2.1配制的溶液內加入濃度為0,26 g/l 0,02 g/l的氯化銅（即0,205 g/l0.015g/l的無水氯化銅）。溶液的PH調整方法與2.2.2相同。2.3 Filtra

25、tion To remove any solid matter which might block theapertures of the spraying device the solution may befiltered before being placed in the reservoir of theapparatus.3 Apparatus All components in contact with the spray or the testsolution shall be made of, or lined with, materials resistant to corr

26、osion caused by the sprayed solutionand which do not influence the corrosivity of thesprayed test solutions.3.1 Spray cabinet The cabinet shall have a capacity of not less than0,2 m3, preferably at least 0,4 m3, since with smallervolumes it can be difficult to ensure the evendistribution of spray. F

27、or large-capacity cabinets, it isnecessary to ensure that the conditions of homogeneity and distribution of the spray are met. The upper parts of the cabinet shall be designed so that drops of sprayed solution formed on its surface do not fall on the test pieces being tested.The size and shape of th

28、e cabinet shall be such thatthe collection rate of solution in the cabinet is withinthe limits specified in section 7.3.2 Heater and temperature controlAn appropriate system will maintain the cabinet and itscontents at the specified temperature (see section 7).The temperature shall be measured at le

29、ast 100 mmfrom the cabinet walls.3.3 Spraying deviceThe device for spraying the salt solution comprises asupply of clean air of controlled pressure and humidity,a reservoir for the solution to be sprayed, and one ormore atomizers.2.3 過濾為避免堵塞噴嘴，溶液在適用之前必須過濾。3 試驗設備用于制作試驗設備的材料必須抗鹽霧腐蝕和不影響試驗結果。3.1 噴霧箱鹽霧箱的

30、容積不小于0.2 m3，最好不小于0.4 m3，因為較小的容積可能難以保證噴霧的均勻性。對于較大的箱，應保證噴霧狀態相同和散布一致。箱頂部要避免試驗時聚積的溶液滴落到試樣上。箱子的形狀和尺寸應使箱內溶液的收集速度符合第7分規定。3.2 加熱系統加熱系統應保持箱內溫度達到第7部分規定，溫度測量區距箱內壁不小于100 mm，并能從箱外讀數。3.3 噴霧裝置噴灑鹽溶液的噴霧裝置應可以提供清潔的空氣和控制壓力及溫度，且提供溶液保證一個或多個噴霧器的噴灑。The compressed air supplied to the atomizers shall bepassed through a filte

31、r to remove all traces of oil orsolid matter, and shall be at an absolute pressure of70 1) to 170 kPa.NOTE - Atomizing nozzles may have a ”critical pressure” at which an abnormal increase in the corrosiveness of the salt spray occurs. If the ”critical pressure” of a nozzle has not been established w

32、ith certainty, control the fluctuations in the air pressure within 0,7 kN/m2 ( 0,1 psi) by installing a suitablepressure regulator valve to minimise the possibility ofoperating the nozzle at its ”critical pressure”.To prevent evaporation of water from the sprayeddroplet, the air shall be humidified

33、before entering theatomizer by passage through a saturation towercontaining hot water at a temperature several degreesCelsius higher than that of the cabinet. Theappropriate temperature depends on the pressureused and on the type of atomizer nozzle, and shall beadjusted so that the rate of collectio

34、n of spray in thecabinet and the concentration of the collected sprayare kept within the specified limits (see 7). The level ofwater must be maintained automatically to ensureadequate humidification.The atomizers shall be made of inert material, for example glass or plastics. Baffles may be used top

35、revent direct impact of spray on the test pieces andthe use of adjustable baffles is helpful in obtaininguniform distribution of the spray within the cabinet. Thelevel of the salt solution in the reservoir shall bemaintained automatically to ensure uniform spraydelivery throughout the test.3.4 Colle

36、cting vessel At least two suitable collecting vessels shall be available, consisting of funnels made of glass or otherchemically inert material, with the stems inserted intograduated cylinders or other similar containers. Funnels with a diameter of 100 mm have a collecting area of approximately 80 c

37、m2. The collecting vessels shall be placed in the zone of the cabinet where the testpieces are placed, one close to the inlet of spray andone remote from this inlet. They shall be placed sothat only spray, and not liquid falling from test piecesor from parts of the cabinet, is collected.提供給噴霧器的壓縮空氣應

38、通過過濾網去除所有的油污和固體雜質，應保證絕對壓力為70 1) 到 170 kPa.注意：霧化噴嘴可能有一個“工作壓力”來保證腐蝕性鹽霧的生成，如果噴嘴的“工作壓力”未被確定，安裝一個適合的壓力調節閥，最大程度將噴嘴壓力保證在“工作壓力”，控制空氣壓力的波動在 0,7 kN/m2 ( 0,1 psi)。為防止霧滴凝結成水的蒸發，空氣進入噴霧器前應經過飽和塔濕化，控制飽和塔熱水的溫度高于鹽霧箱內試驗溫度，溫度的設定依據使用的壓力和噴嘴的種類，并加以調整，所以箱內噴霧的溫度比例與霧氣的凝結保持在限定的范圍內（見7）。霧化器應使用抗腐蝕的材料制作，比如玻璃或塑料。導流板的作用是防止直接在試片上噴涂，

39、可調節導流板有助于在試驗箱獲得不變的噴涂散布，在整個噴涂過程中，容器中鹽溶液的濃度應當自動保持不變。3.4 收集裝置箱內至少放兩個收集器，一個靠近噴嘴，一個遠離噴嘴。收集器用玻璃等惰性材料制成漏斗形狀，直徑100 mm收集面積80 cm2.漏斗插入帶有刻度的容器中，要求收集的是鹽霧，而不是從試樣或其他部位滴下的液體。3.5 Re-use of apparatus If the equipment has been used for a spray test or forany other purpose with a solution differing from theone specifi

40、ed for the test to be carried out, it shall bethoroughly cleaned before use. Apparatus used inCASS tests should not be used in other cycles.The equipment shall then be operated for a minimumperiod of 24 h and the pH of the collected solutionshall be measured to ensure that pH is correctthroughout th

41、e entire spraying period, before any testpieces are placed in the chamber.4 Method for evaluating thecorrosivity of the chamberTo check the reproducibility of the test results forindividual apparatuses in different laboratories, it isnecessary to verify the apparatus at regular intervalsas described

42、 in 4.1.1-4.1.3.4.1 NSS test4.1.1 Reference test piecesTo verify the apparatus, use four reference test pieces1 mm 0,2 mm thick and 50 mm x 80 mm, of CR4grade steel in accordance with ISO 3574, with a practically faultless surface (”Practically faultless” means free from pores, marks, scratches, and

43、 any light discoloration), and a mat finish (arithmetical mean deviation of theprofile Ra = 1,3 m 0,4 m). Cut these reference test pieces from cold-rolled sheet or strips.Clean the reference test pieces carefully immediatelybefore testing. Beside the specification given in section5, cleaning shall e

44、liminate all traces of dirt, oil orother foreign matter capable of influencing the testresults.Use one of the following methods:a) Clean the reference test pieces by vapour degreasing with a chlorated hydrocarbon. Use threesuccessive treatments of 1 min each, with an intervalof at least 1 min betwee

45、n the treatments.b) Thoroughly clean the reference test pieces with anappropriate organic solvent (hydrocarbon with aboiling point between 60 C an 120 C) using aclean soft brush or an ultrasonic cleaning device.Carry out the cleaning in a vessel full of solvent.After cleaning, rinse the reference te

46、st pieces withfresh solvent, and then dry them.3.5 再利用裝置使用不同溶液做試驗之前，必須徹底清洗鹽霧箱。儀器使用于做CASS試驗時不能使用其它的周期。在放入試樣之前，設備至少空運行24小時，必須測量收集液的PH值，保證整個噴霧的PH在規定的范圍內。4評價噴霧箱腐蝕性能的方法為了檢驗設備或不同實驗室里同類設備試驗結果的重復性，應按4.1.14.1.3 規定驗證。4.1 NSS試驗（中性鹽霧試驗）4.1.1參照試樣參照試樣采取四塊CR4鋼板，其表面質量應符合ISO357高精度的要求（“高精度”是指無毛孔，標記，劃痕，和任何光澤變色），板厚1mm

47、0,2 mm，尺寸50 mm x 80 mm表面粗糙度Ra = 1,3 m 0,4 m。從冷軋鋼板或帶上截取試樣參照試樣清理后立即試驗，除按第5部分規定外，還應清除一切塵埃、油或影響結果的其他物質。選用以下一種清洗辦法：a)用氯化碳氫合物蒸汽脫脂清洗試樣采用3次1 min的連續處理，每一連續處理時間至少間隔1 min。b）采取清潔的軟刷或超聲清洗裝置用適當有機溶劑（沸點在60 C120 C的碳氫化合物）徹底清洗試樣后，用新溶劑漂洗試樣，然后干燥。c) Other cleaning methods may be used, afteragreement between the intereste

48、d parties, subjectto the result being comparable.Determine the mass of the reference test pieces withan accuracy of 1 mg. Protect one side of thereference test pieces with a removable coating, forexample an adhesive plastic film.4.1.2 Arrangement of the reference testpiecesPosition the four referenc

49、e test pieces in four differentquadrants in the test apparatus, with the unprotectedface upwards, and at an angle of 20 5 from thevertical.NOTE - Other angles may be recommended in thespecification (e.g. 30 5).The support for the reference test pieces shall bemade of, or coated with, inert materials

50、 such asplastics. The upper edge of the reference test piecesshall be level with the top of the salt spray collector.The test duration is 96 h.4.1.3 Determination of mass lossAfter completed test, remove the protective coating.Remove the corrosion products by immersing them ina cleaning solution of

51、hydrochloric acid (20 =1,18 g/ml) of recognized analytical grade, 50 % (V/V),in water, inhibited by 3,5 g of hexamethylene tetramineper litre.After stripping, thoroughly clean the reference testpieces at ambient temperature with water, then withacetone, followed by drying.Weigh the reference test pi

52、eces to the nearest 1 mgand calculate the mass loss in grams per squaremetre.4.1.4 Checking of NSS apparatus operationThe operation of the test apparatus is satisfactory ifthe mass loss of each reference test piece is 140 g/m2 40 g/m2.4.2. AASS testNo experimental procedure exists to determine theco

53、rrosivity of the test chamber for AASS in this standard.c）經相關各方協商，可以采用其他清洗方法。清洗后的試樣吹干稱重，精確到 1 mg，然后用可剝性塑料膜保護試樣背面。4.1.3 參照試樣的放置試樣放置在箱內四角，未保護的一面朝上并與垂直方向成20 5角度。注意：可以采用其他規范范圍的角度例如30 5用惰性材料（塑料）制成或涂覆參照試樣架，參照試樣上邊應與鹽霧收集器上部處于同一水平。測試時間為96小時4.1.3 測定質量損失完整試驗后，除掉試樣背面的保護膜，用鹽酸溶液(20 = 1,18 g/ml)其中加入3,5 g的六次甲基四胺緩蝕劑

54、，泡試樣除去腐蝕產物。在室溫中用水清洗試樣，再用丙酮清洗，干燥稱重。試樣稱重精確倒1 mg，計算質量損失。4.1.4 檢驗NSS裝置每塊參照試樣的質量損失在140 g/m240 g/m2.范圍內說明設備運行正常。4.2 AASS試驗沒有測量乙酸鹽霧試驗箱腐蝕性的試驗規程。4.2.1 Electrolytic coatingElectrolytic coating is a process that results in differentthicknesses depending on the time spent in theelectroplating bath, but the thic

55、kness is irregular at thebottom of the part and virtually inexistent in bores,internal threads, etc. if adequate methods are notapplied.This operation weakens steel parts due to thepresence of hydrogen, which explains why degassingis necessary for parts with high mechanical propertiesevery time this process is specified.An organic finish may be used on this