Designation:B 117–03
Standard Practice for
Operating Salt Spray (Fog)Apparatus 1
This standard is issued under the ?xed designation B 117;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript 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.Scope
1.1This practice covers the apparatus,procedure,and conditions required to create and maintain the salt spray (fog)test environment.Suitable apparatus which may be used is described in Appendix X1.
1.2This practice does not prescribe the type of test speci-men or exposure periods to be used for a speci?c product,nor the interpretation to be given to the results.
1.3The values stated in SI units are to be regarded as standard.The inch-pound units in parentheses are provided for information and may be approximate.
1.4This standard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.
2.Referenced Documents 2.1ASTM Standards:
B 368Method for Copper-Accelerated Acetic Acid-Salt Spray (Fog)Testing (CASS Test)2
D 609Practice for Preparation of Cold-Rolled Steel Panels for Testing Paint,Varnish,Conversion Coatings,and Related Coating Products 3
D 1193Speci?cation for Reagent Water 4
D 1654Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments 3
E 70Test Method for pH of Aqueous Solutions with the Glass Electrode 5
E 691Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method 6
G 85Practice for Modi?ed Salt Spray (Fog)Testing 73.Signi?cance and Use
3.1This practice provides a controlled corrosive environ-ment which has been utilized to produce relative corrosion resistance information for specimens of metals and coated metals exposed in a given test chamber.
3.2Prediction of performance in natural environments has seldom been correlated with salt spray results when used as stand alone data.
3.2.1Correlation and extrapolation of corrosion perfor-mance based on exposure to the test environment provided by this practice are not always predictable.
3.2.2Correlation and extrapolation should be considered only in cases where appropriate corroborating long-term atmo-spheric exposures have been conducted.
3.3The reproducibility of results in the salt spray exposure is highly dependent on the type of specimens tested and the evaluation criteria selected,as well as the control of the operating variables.In any testing program,sufficient repli-cates should be included to establish the variability of the results.Variability has been observed when similar specimens are tested in different fog chambers even though the testing conditions are nominally similar and within the ranges speci-?ed in this practice.
4.Apparatus
4.1The apparatus required for salt spray (fog)exposure consists of a fog chamber,a salt solution reservoir,a supply of suitably conditioned compressed air,one or more atomizing nozzles,specimen supports,provision for heating the chamber,and necessary means of control.The size and detailed con-struction of the apparatus are optional,provided the conditions obtained meet the requirements of this practice.
4.2Drops of solution which accumulate on the ceiling or cover of the chamber shall not be permitted to fall on the specimens being exposed.
1
This practice is under the jurisdiction of ASTM Committee G01on Corrosion of Metals and is the direct responsibility of Subcommittee G01.05on Laboratory Corrosion Tests.
Current edition approved October 1,2003.Published October 2003.Originally approved in https://www.doczj.com/doc/7f10461404.html,st previous edition approved in 2002as B 117–02.2
Annual Book of ASTM Standards ,V ol 02.05.3
Annual Book of ASTM Standards ,V ol 06.01.4
Annual Book of ASTM Standards ,V ol 11.01.5
Annual Book of ASTM Standards ,V ol 15.05.6
Annual Book of ASTM Standards ,V ol 14.02.
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Annual Book of ASTM Standards ,V ol 03.02.
1
Copyright ?ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United
States.
4.3Drops of solution which fall from the specimens shall not be returned to the solution reservoir for respraying.
4.4Material of construction shall be such that it will not affect the corrosiveness of the fog.
4.5All water used for this practice shall conform to Type IV water in Speci?cation D1193(except that for this practice limits for chlorides and sodium may be ignored).This does not apply to running tap water.All other water will be referred to as reagent grade.
5.Test Specimens
5.1The type and number of test specimens to be used,as well as the criteria for the evaluation of the test results,shall be de?ned in the speci?cations covering the material or product being exposed or shall be mutually agreed upon between the purchaser and the seller.
6.Preparation of Test Specimens
6.1Specimens shall be suitably cleaned.The cleaning method shall be optional depending on the nature of the surface and the contaminants.Care shall be taken that specimens are not recontaminated after cleaning by excessive or careless handling.
6.2Specimens for the evaluation of paints and other organic coatings shall be prepared in accordance with applicable speci?cation(s)for the material(s)being exposed,or as agreed upon between the purchaser and the supplier.Otherwise,the test specimens shall consist of steel meeting the requirements of Practice D609and shall be cleaned and prepared for coating in accordance with the applicable procedure of Practice D609.
6.3Specimens coated with paints or nonmetallic coatings shall not be cleaned or handled excessively prior to test.
6.4Whenever it is desired to determine the development of corrosion from an abraded area in the paint or organic coating, a scratch or scribed line shall be made through the coating with a sharp instrument so as to expose the underlying metal before testing.The conditions of making the scratch shall be as de?ned in Test Method D1654,unless otherwise agreed upon between the purchaser and the seller.
6.5Unless otherwise speci?ed,the cut edges of plated, coated,or duplex materials and areas containing identi?cation marks or in contact with the racks or supports shall be protected with a suitable coating stable under the conditions of the practice.
N OTE1—Should it be desirable to cut test specimens from parts or from preplated,painted,or otherwise coated steel sheet,the cut edges shall be protected by coating them with paint,wax,tape,or other effective media so that the development of a galvanic effect between such edges and the adjacent plated or otherwise coated metal surfaces,is prevented.
7.Position of Specimens During Exposure
7.1The position of the specimens in the salt spray chamber during the test shall be such that the following conditions are met:
7.1.1Unless otherwise speci?ed,the specimens shall be supported or suspended between15and30°from the vertical and preferably parallel to the principal direction of?ow of fog through the chamber,based upon the dominant surface being tested.
7.1.2The specimens shall not contact each other or any metallic material or any material capable of acting as a wick.
7.1.3Each specimen shall be placed to permit unencum-bered exposure to the fog.
7.1.4Salt solution from one specimen shall not drip on any other specimen.
N OTE2—Suitable materials for the construction or coating of racks and supports are glass,rubber,plastic,or suitably coated wood.Bare metal shall not be used.Specimens shall preferably be supported from the bottom or the side.Slotted wooden strips are suitable for the support of?at panels.Suspension from glass hooks or waxed string may be used as long as the speci?ed position of the specimens is obtained,if necessary by means of secondary support at the bottom of the specimens.
8.Salt Solution
8.1The salt solution shall be prepared by dissolving561 parts by mass of sodium chloride in95parts of water conforming to Type IV water in Speci?cation D1193(except that for this practice limits for chlorides and sodium may be ignored).Careful attention should be given to the chemical content of the salt.The salt used shall be sodium chloride with not more than0.3%by mass of total impurities.Halides (Bromide,Fluoride,and Iodide)other than Chloride shall constitute less than0.1%by mass of the salt content.Copper content shall be less than0.3ppm by mass.Sodium chloride containing anti-caking agents shall not be used because such agents may act as corrosion inhibitors.See Table1for a listing of these impurity restrictions.Upon agreement between the purchaser and the seller,analysis may be required and limits established for elements or compounds not speci?ed in the chemical composition given above.
TABLE1Maximum Allowable Limits for Impurity Levels in
Sodium Chloride A,B
Impurity Description Allowable Amount Total Impurities#0.3% Halides(Bromide,Fluoride and Iodide)excluding Chloride#0.1% Copper<0.3ppm
Anti-caking Agents0.0%
A A common formula used to calculate the amount of salt required by mass to achieve a5%salt solution of a known mass of water is:
.053X Mass of Water5Mass of NaCl required
The mass of water is1g per1mL.To calculate the mass of salt required in grams to mix1L of a5%salt solution,multiply.053by1000g(35.27oz.,the mass of 1L of water).This formula yields a result of53g(1.87oz.)of NaCl required for each liter of water to achieve a5%salt solution by mass.
The0.053multiplier for the sodium chloride used above is derived by the following:
1000g~mass of a full L of water!divided by0.95
~water is only95%of the total mixture by mass!yields1053g
This1053g is the total mass of the mixture of one L of water with a5%sodium chloride concentration.1053g minus the original weight of the L of water,1000g, yields53g for the weight of the sodium chloride.53g of total sodium chloride divided by the original1000g of water yields a0.053multiplier for the sodium chloride.
As an example:to mix the equivalent of200L(52.83gal)of5%sodium chloride solution,mix10.6kg(23.37lb)of sodium chloride into200L(52.83gal)of water. 200L of water weighs200,000g.200,000g of water x.053(sodium chloride multiplier)=10,600g of sodium chloride,or10.6kg.
B In order to ensure that the proper salt concentration was achieved when mixing the solution,it is recommended that the solution be checked with either a salimeter hydrometer or speci?c gravity hydrometer.When using a salimeter hydrometer,the measurement should be between4and6%at25°C(77°F).When using a speci?c gravity hydrometer,the measurement should be between1.0255and1.0400at 25°C
(77°F).
8.2The pH of the salt solution shall be such that when atomized at35°C(95°F)the collected solution will be in the pH range from6.5to7.2(Note3).Before the solution is atomized it shall be free of suspended solids(Note4).The pH measurement shall be made at25°C(77°F)using a suitable glass pH-sensing electrode,reference electrode,and pH meter system in accordance with Test Method E70.
N OTE3—Temperature affects the pH of a salt solution prepared from water saturated with carbon dioxide at room temperature and pH adjust-ment may be made by the following three methods:
(1)When the pH of a salt solution is adjusted at room temperature,and atomized at35°C(95°F),the pH of the collected solution will be higher than the original solution due to the loss of carbon dioxide at the higher temperature.When the pH of the salt solution is adjusted at room temperature,it is therefore necessary to adjust it below6.5so the collected solution after atomizing at35°C(95°F)will meet the pH limits of6.5to 7.2.Take about a50-mL sample of the salt solution as prepared at room temperature,boil gently for30s,cool,and determine the pH.When the pH of the salt solution is adjusted to6.5to7.2by this procedure,the pH of the atomized and collected solution at35°C(95°F)will come within this range.
(2)Heating the salt solution to boiling and cooling to35°C(95°F)and maintaining it at35°C(95°F)for approximately48h before adjusting the pH produces a solution the pH of which does not materially change when atomized at35°C(95°F).
(3)Heating the water from which the salt solution is prepared to35°C (95°F)or above,to expel carbon dioxide,and adjusting the pH of the salt solution within the limits of6.5to7.2produces a solution the pH of which does not materially change when atomized at35°C(95°F).
N OTE4—The freshly prepared salt solution may be?ltered or decanted before it is placed in the reservoir,or the end of the tube leading from the solution to the atomizer may be covered with a double layer of cheesecloth to prevent plugging of the nozzle.
N OTE5—The pH can be adjusted by additions of dilute ACS reagent grade hydrochloric acid or sodium hydroxide solutions.
9.Air Supply
9.1The compressed air supply to the Air Saturator Tower shall be free of grease,oil,and dirt before use by passing through well-maintained?lters.(Note6)This air should be maintained at a sufficient pressure at the base of the Air Saturator Tower to meet the suggested pressures of Table2at the top of the Air Saturator Tower.
N OTE6—The air supply may be freed from oil and dirt by passing it through a suitable oil/water extractor(that is commercially available)to stop any oil from reaching the Air Saturator Tower.Many oil/water extractors have an expiration indicator,proper preventive maintenance intervals should take these into account.
9.2The compressed air supply to the atomizer nozzle or nozzles shall be conditioned by introducing it into the bottom of a tower?llwed with water.A common method of introduc-ing the air is through an air dispersion device(X1.4.1).The level of the water must be maintained automatically to ensure adequate humidi?cation.It is common practice to maintain the temperature in this tower between46and49°C(114–121°F)to offset the cooling effect of expansion to atmospheric pressure during the atomization process.Table2in9.3of this practice shows the temperature,at different pressures,that are com-monly used to offset the cooling effect of expansion to atmospheric pressure.
9.3Careful attention should be given to the relationship of tower temperature to pressure since this relationship can have a direct impact to maintaining proper collection rates(Note7). It is preferable to saturate the air at temperatures well above the chamber temperature as insurance of a wet fog as listed in Table2.
N OTE7—If the tower is run outside of these suggested temperature and pressure ranges to acheive proper collection rates as described in10.2of this practice,other means of verifying the proper corrosion rate in the chamber should be investigated,such as the use of control specimens (panels of known performance in the test conducted).It is preferred that control panels be provided that bracket the expected test specimen performance.The controls allow for the normalization of test conditions during repeated running of the test and will also allow comparisons of test results from different repeats of the same test.(Refer to Appendix X3, Evaluation of Corrosive Conditions,for mass loss procedures).
10.Conditions in the Salt Spray Chamber
10.1Temperature—The exposure zone of the salt spray chamber shall be maintained at35+1.1?1.7°C (95+2?3°F).Each set point and its tolerance represents an operational control point for equilibrium conditions at a single location in the cabinet which may not necessarily represent the uniformity of conditions throughout the cabinet.The tempera-ture within the exposure zone of the closed cabinet shall be recorded(Note8)at least twice a day at least7h apart(except on Saturdays,Sundays,and holidays when the salt spray test is not interrupted for exposing,rearranging,or removing test specimens or to check and replenish the solution in the reservoir)
N OTE8—A suitable method to record the temperature is by a continu-ous recording device or by a thermometer which can be read from outside the closed cabinet.The recorded temperature must be obtained with the salt spray chamber closed to avoid a false low reading because of wet-bulb effect when the chamber is open.
10.2Atomization and Quantity of Fog—Place at least two clean fog collectors per atomizer tower within the exposure zone so that no drops of solution will be collected from the test specimens or any other source.Position the collectors in the proximity of the test specimens,one nearest to any nozzle and the other farthest from all nozzles.A typical arrangement is shown in Fig.1.The fog shall be such that for each80 cm2(12.4in.2)of horizontal collecting area,there will be collected from1.0to2.0mL of solution per hour based on an average run of at least16h(Note9).The sodium chloride concentration of the collected solution shall be561mass% (Notes9-11).The pH of the collected solution shall be6.5to 7.2.The pH measurement shall be made as described in8.2 (Note3).
N OTE9—Suitable collecting devices are glass or plastic funnels with TABLE2Suggested Temperature and Pressure guideline for the top of the Air Saturator Tower for the operation of a test at35°C
(95°F)
Air Pressure,kPa Temperature,°C Air Pressure,PSI Temperature,°F 834612114
964714117
1104816119
1244918
121
the stems inserted through stoppers into graduated cylinders,or crystal-lizing dishes.Funnels and dishes with a diameter of 10cm (3.94in.)have an area of about 80cm 2(12.4in.2).
N OTE 10—A solution having a speci?c gravity of 1.0255to 1.0400at 25°C (77°F)will meet the concentration requirement.The sodium chloride concentration may also be determined using a suitable salinity meter (for example,utilizing a sodium ion-selective glass electrode)or colorimetrically as follows.Dilute 5mL of the collected solution to 100mL with distilled water and mix thoroughly;pipet a 10-mL aliquot into an evaporating dish or casserole;add 40mL of distilled water and 1mL of 1%potassium chromate solution (chloride-free)and titrate with 0.1N silver nitrate solution to the ?rst appearance of a permanent red coloration.A solution that requires between 3.4and 5.1mL of 0.1N silver nitrate solution will meet the concentration requirements.
N OTE 11—Salt solutions from 2to 6%will give the same results,though for uniformity the limits are set at 4to 6%.
10.3The nozzle or nozzles shall be so directed or baffled that none of the spray can impinge directly on the test specimens.
11.Continuity of Exposure
11.1Unless otherwise speci?ed in the speci?cations cover-ing the material or product being tested,the test shall be continuous for the duration of the entire test period.Continu-ous operation implies that the chamber be closed and the spray operating continuously except for the short daily interruptions necessary to inspect,rearrange,or remove test specimens,to check and replenish the solution in the reservoir,and to make necessary recordings as described in Section 10.Operations shall be so scheduled that these interruptions are held to a minimum.
12.Period of Exposure
12.1The period of exposure shall be as designated by the speci?cations covering the material or product being tested or as mutually agreed upon between the purchaser and the seller.
N OTE 12—Recommended exposure periods are to be as agreed upon between the purchaser and the seller,but exposure periods of multiples of 24h are suggested.
13.Cleaning of Tested Specimens
13.1Unless otherwise speci?ed in the speci?cations cover-ing the material or product being tested,specimens shall be treated as follows at the end of the test:
13.1.1The specimens shall be carefully removed.
13.2Specimens may be gently washed or dipped in clean running water not warmer than 38°C (100°F)to remove salt deposits from their surface,and then immediately dried.14.Evaluation of Results
14.1A careful and immediate examination shall be made as required by the speci?cations covering the material or product being tested or by agreement between the purchaser and the seller.
15.Records and Reports
15.1The following information shall be recorded,unless otherwise prescribed in the speci?cations covering the material or product being tested:
15.1.1Type of salt and water used in preparing the salt solution,
15.1.2All readings of temperature within the exposure zone of the chamber,
15.1.3Daily records of data obtained from each fog-collecting device including the following:
15.1.3.1V olume of salt solution collected in millilitres per hour per 80cm 2(12.4in.2),
15.1.3.2Concentration or speci?c gravity at 35°C (95°F)of solution collected,and
15.1.3.3pH of collected
solution.
N OTE —This ?gure shows a typical fog collector arrangement for a single atomizer tower cabinet.The same fog collector arrangement is also applicable for multiple atomizer tower and horizontal (“T”type)atomizer tower cabinet constructions as well.
FIG.1Arrangement of Fog
Collectors
15.2Type of specimen and its dimensions,or number or description of part,
15.3Method of cleaning specimens before and after testing, 15.4Method of supporting or suspending article in the salt spray chamber,
15.5Description of protection used as required in6.5, 15.6Exposure period,
15.7Interruptions in exposure,cause,and length of time, and
15.8Results of all inspections.
N OTE13—If any of the atomized salt solution which has not contacted the test specimens is returned to the reservoir,it is advisable to record the concentration or speci?c gravity of this solution also.
16.Keywords
16.1controlled corrosive environment;corrosive condi-tions;determining mass loss;salt spray(fog)exposure
APPENDIXES
(Nonmandatory Information)
X1.CONSTRUCTION OF APPARATUS
X1.1Cabinets
X1.1.1Standard salt spray cabinets are available from several suppliers,but certain pertinent accessories are required before they will function according to this practice and provide consistent control for duplication of results.
X1.1.2The salt spray cabinet consists of the basic chamber, an air-saturator tower,a salt solution reservoir,atomizing nozzles,specimen supports,provisions for heating the cham-ber,and suitable controls for maintaining the desired tempera-ture.
X1.1.3Accessories such as a suitable adjustable baffle or central fog tower,automatic level control for the salt reservoir, and automatic level control for the air-saturator tower are pertinent parts of the apparatus.
X1.1.4The size and shape of the cabinet shall be such that the atomization and quantity of collected solution is within the limits of this practice.
X1.1.5The chamber shall be made of suitably inert mate-rials such as plastic,glass,or stone,or constructed of metal and lined with impervious plastics,rubber,or epoxy-type materials or equivalent.
X1.1.6All piping that contacts the salt solution or spray should be of inert materials such as plastic.Vent piping should be of sufficient size so that a minimum of back pressure exists and should be installed so that no solution is trapped.The exposed end of the vent pipe should be shielded from extreme air currents that may cause?uctuation of pressure or vacuum in the cabinet.
X1.2Temperature Control
X1.2.1The maintenance of temperature within the salt chamber can be accomplished by several methods.It is generally desirable to control the temperature of the surround-ings of the salt spray chamber and to maintain it as stable as possible.This may be accomplished by placing the apparatus in a constant-temperature room,but may also be achieved by surrounding the basic chamber of a jacket containing water or air at a controlled temperature.
X1.2.2The use of immersion heaters in an internal salt solution reservoir or within the chamber is detrimental where heat losses are appreciable because of solution evaporation and radiant heat on the specimens.
X1.3Spray Nozzles
X1.3.1Satisfactory nozzles may be made of hard rubber, plastic,or other inert materials.The most commonly used type is made of plastic.Nozzles calibrated for air consumption and solution-atomized are available.The operating characteristics of a typical nozzle are given in Table X1.1.
X1.3.2It can readily be seen that air consumption is relatively stable at the pressures normally used,but a marked reduction in solution sprayed occurs if the level of the solution is allowed to drop appreciably during the test.Thus,the level of the solution in the salt reservoir must be maintained automatically to ensure uniform fog delivery during the test.8 X1.3.3If the nozzle selected does not atomize the salt solution into uniform droplets,it will be necessary to direct the spray at a baffle or wall to pick up the larger drops and prevent them from impinging on the test specimens.Pending a com-plete understanding of air-pressure effects,and so forth,it is important that the nozzle selected shall produce the desired 8A suitable device for maintaining the level of liquid in either the saturator tower or reservoir of test solution may be designed by a local engineering group,or may be purchased from manufacturers of test cabinets as an accessory.
TABLE X1.1Operating Characteristics of Typical Spray Nozzle Siphon
Height
,cm
Air Flow,dm3/min Solution Consumption,cm3/h
Air Pressure,kPa Air Pressure,kPa
34691031383469103138 101926.531.5362100384045845256 201926.531.536636276037204320 301926.531.5360138030003710 401926.631.536078021242904
Siphon
Height,
in.
Air Flow,
L/min
Solution
Consumption,mL/h
Air Pressure,psi Air Pressure,psi
51015205101520 41926.531.5362100384045845256 81926.531.536636276037204320 121926.531.5360138030003710 161926.631.53607802124
2904
condition when operated at the air pressure selected.Nozzles are not necessarily located at one end,but may be placed in the center and can also be directed vertically up through a suitable tower.
X1.4Air for Atomization
X1.4.1The air used for atomization must be free of grease, oil,and dirt before use by passing through well-maintained
?lters.Room air may be compressed,heated,humidi?ed,and washed in a water-sealed rotary pump if the temperature of the water is suitably controlled.Otherwise cleaned air may be introduced into the bottom of a tower?lled with water through a porous stone or multiple nozzles.The level of the water must be maintained automatically to ensure adequate humidi?cation.
A chamber operated in accordance with this method and Appendix X1will have a relative humidity between95and 98%.Since salt solutions from2to6%will give the same results(though for uniformity the limits are set at4to6%),it is preferable to saturate the air at temperatures well above the chamber temperature as insurance of a wet fog.Table X1.2 shows the temperatures,at different pressures,that are required to offset the cooling effect of expansion to atmospheric pressure.
X1.4.2Experience has shown that most uniform spray chamber atmospheres are obtained by increasing the atomizing air temperature sufficiently to offset heat losses,except those that can be replaced otherwise at very low-temperature gradi-ents.
X1.5Types of Construction
X1.5.1A modern laboratory cabinet is shown in Fig.X1.1. Walk-in chambers are usually constructed with a sloping ceiling.Suitably located and directed spray nozzles avoid ceiling accumulation and drip.Nozzles may be located at the ceiling,or0.91m(3ft)from the?oor directed upward at30to 60°over a passageway.The number of nozzles depends on type and capacity and is related to the area of the test space.An11 to19L(3to5-gal)reservoir is required within the chamber, with the level controlled.The major features of a walk-in type cabinet,which differs signi?cantly from the laboratory type, are illustrated in Fig.X1.2.Construction of a plastic nozzle, such as is furnished by several suppliers,is shown in Fig.X1.3.
TABLE X1.2Temperature and Pressure Requirements for
Operation of Test at95°F
Air Pressure,kPa
8396110124 Temperature,°C46474849
Air Pressure,psi
12141618 Temperature,°F114117119
121
N OTE1—u—Angle of lid,90to125°
1—Thermometer and thermostat for controlling heater(Item No.8)in base
2—Automatic water leveling device
3—Humidifying tower
4—Automatic temperature regulator for controlling heater(Item No.5)
5—Immersion heater,nonrusting
6—Air inlet,multiple openings
7—Air tube to spray nozzle
8—Heater in base
9—Hinged top,hydraulically operated,or counterbalanced
10—Brackets for rods supporting specimens,or test table
11—Internal reservoir
12—Spray nozzle above reservoir,suitably designed,located,and baffled
12A—Spray nozzle housed in dispersion tower located preferably in center of cabinet(typical examples)
13—Water seal
14—Combination drain and exhaust.Exhaust at opposite side of test space from spray nozzle(Item12),but preferably in combination with drain,waste trap,and forced draft waste pipe(Items16,17,and19).
16—Complete separation between forced draft waste pipe(Item17)and combination drain and exhaust(Items14and19)to avoid undesirable suction or back pressure.
17—Forced draft waste pipe
18—Automatic leveling device for reservoir
19—Waste trap
20—Air space or water jacket
21—Test table or rack,well below roof area
N OTE2—This?gure shows the various components including alternate arrangements of the spray nozzles and solution reservoir.
FIG.X1.1Typical Salt Spray Cabinet
https://www.doczj.com/doc/7f10461404.html,E OF THE SALT SPRAY (FOG)TEST IN RESEARCH
X2.1This practice is primarily used for process quali?ca-tion and quality acceptance.Regarding any new applications,it is essential to correlate the results of this practice with actual ?eld exposure results.(See Fig.X2.1.)
X2.2The salt spray has been used to a considerable extent for the purpose of comparing different materials or ?nishes.It should be noted there is usually not a direct relation between salt spray (fog)resistance and resistance to corrosion in other media,because the chemistry of the reactions,including the formation of ?lms and their protective value,frequently varies greatly with the precise conditions https://www.doczj.com/doc/7f10461404.html,rmed personnel are aware of the erratic composition of basic alloys,the possibility of wide variations in quality and thickness of plated items produced on the same racks at the same time,and the consequent need for a mathematical determination of the number of specimens required to constitute an adequate sample for test purposes.In this connection it is well to point out that Practice B 117is not applicable to the study or testing of decorative chromium plate (nickel-chromium)on steel or on zinc-base die castings or of cadmium plate on steel.For this purpose Method B 368and Practice G 85are available,which are also considered by some to be superior for comparison of chemically treated aluminum (chromated,phosphated,or an-odized),although ?nal conclusions regarding the validity of test results related to service experience have not been reached.Practice B 117and Practice G 85are considered to be most useful in estimating the relative behavior of closely related materials in marine atmospheres,since it simulates the basic conditions with some acceleration due to either wetness or temperature,or
both.
N OTE —The controls are the same,in general as for the smaller laboratory type cabinet (Fig.X1.1),but are sized to care for the larger cube.The chamber has the following features:
u —Angle of ceiling,90to 125°1—Heavy insulated outer panels 2—Air space
3—Low-watt density heaters,or steam coils
4—Single-or double-,full-opening door (refrigeration type),with
inward sloping door sill 5—Viewing window/s 6—Inner chamber vent 7—Inner chamber drain 8—Duct boards on ?oor
FIG.X1.2Walk-in Chamber,1.5by 2.4m (5by 8ft)and Upward in Overall
Size
FIG.X1.3Typical Spray
Nozzle
X3.EV ALUATION OF CORROSIVE CONDITIONS
X3.1General —This appendix covers test panels and pro-cedures for evaluating the corrosive conditions within a salt spray cabinet.The procedure involves the exposure of steel test panels and the determination of their mass losses in a speci?ed period of time.This may be done monthly or more frequently to ensure consistent operation over time.It is also useful for correlating the corrosive conditions among different cabinets.X3.2Test Panels —The required test panels,76by 127by 0.8mm (3.0by 5.0by .0315in.),are made from SAE 1008commercial-grade cold-rolled carbon steel (UNS G10080).X3.3Preparation of Panels Before Testing —Clean panels before testing by degreasing only,so that the surfaces are free of dirt,oil,or other foreign matter that could in?uence the test results.After cleaning,weigh each panel on an analytical balance to the nearest 1.0mg and record the mass.
X3.4Positioning of Test Panels —Place a minimum of two weighed panels in the cabinet,with the 127-mm (5.0in.)length supported 30°from vertical.Place the panels in the proximity of the condensate collectors.(See Section 6.)
X3.5Duration of Test —Expose panels to the salt fog for 48to 168h.
X3.6Cleaning of Test Panels After Exposure —After re-moval of the panels from the cabinet,rinse each panel immediately with running tap water to remove salt,and rinse in reagent grade water (see Speci?cation D 1193,Type IV).Chemically clean each panel for 10min at 20to 25°C in a fresh solution prepared as follows:
Mix 1000mL of hydrochloric acid (sp gr 1.19)with 1000mL re-agent grade water (D 1193,Type IV)and add 10g of hexamethyl-ene tetramine.After cleaning,rinse each panel with reagent grade water (Type IV)and dry (see
13.2).
(1)Salt Solution:561parts by mass of sodium chloride (NaCl)in 95parts by mass of Speci?cation D 1193Type IV water.(2)pH 6.5to 7.2of collected solution.
(3)The exposure zone of the salt spray chamber shall be maintained at 35+1.1-1.7°C (95+2-3°F).Each set point and its tolerance represents an operational control point for equilibrium conditions at a single location in the cabinet which may not necessarily represent the uniformity of conditions throughout the cabinet.(4)Fog at a rate of 1.0to 2.0mL/hr per 80cm 2of horizontal collection area.Note:Dashed chart lines indicate temperature tolerance limits.Note:Reprinted with permission.
FIG.X2.1Standard Practice for Operating Salt Spray (Fog)
Apparatus
X3.7Determining Mass Loss —Immediately after drying,determine the mass loss by reweighing and subtracting panel mass after exposure from its original mass.
X3.7.1Data generated in the interlaboratory study using this method are available from ASTM as a Research Report.9
X3.8Precision and Bias—Steel Panel Test:
X3.8.1An interlaboratory test program using three different sets of UNS G10080steel panels,76by 127by 0.8mm (3.0by 5.0by .0315in.)has shown that the repeatability of the mass loss of the steel panels,that is,the consistency in mass loss results that may be expected when replicate panels are run simultaneously in a salt spray cabinet,is dependent upon exposure time and the panel lot or source.The interlaboratory program yielded repeatability standard deviations,S r ,from which 95%repeatability limits,r ,were calculated as follows (see Practice E 691):
r 52.8S r
(X3.1)
The values of S r and r are reported in Table X3.1.Note that the corrosion rate of steel in this environment is approximately constant over the exposure interval and that the ratio of the standard deviation to the average mass loss,the coefficient of variation,Cv ,varies between 5and 10%with a weighted average of 7.4%and an r of 621%of the average mass loss.X3.8.2This interlaboratory program also produced results on the reproducibility of results,that is,the consistency of mass loss results in tests in different laboratories or in different cabinets in the same facility.This program yielded reproduc-ibility standard deviations,S R ,from which 95%reproducibil-ity limits,R ,were calculated as follows (See Practice E 691):
R 52.8S R
(X3.2)
The values of S R and R are reported in Table X3.2.Note that the ratio of standard deviation to the average mass loss,the coefficient of variation,Cv ,varies between 8to 18%with a weighted average of 12.7%and an R of 636%of the average mass loss.
X3.8.3The mass loss of steel in this salt spray practice is dependent upon the area of steel exposed,the temperature,time of exposure,salt solution make up and purity,pH,spray conditions,and the metallurgy of the steel.The procedure in Appendix X3for measuring the corrosivity of neutral salt spray cabinets with steel panels has no bias because the value of corrosivity of the salt spray is de?ned only in terms of this practice.
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9
Available from ASTM Headquarters.Request RR No.G1-1003.
TABLE X3.1Repeatability Statistics
N OTE —Based on two replicates in every test run.No.=number of different salt spray cabinets in test program;r =95%repeatability limits,g;Cv =S r /avg,coefficient of variation,%;and S r =repeatability standard deviations,g.
Materials Test Dura-tion,h Average Mass Loss,g S r ,g C v,%r ,g No.QP1480.81700.05887.200.164612QP196 1.53470.10487.280.293412QP1168 2.59960.24989.610.699412AP 480.77870.0403 5.170.112810AP 96 1.40940.0923 6.550.258410AP 168 2.43090.1594 6.560.446310QP2480.85660.06868.010.19215QP296 1.57200.0976 6.210.27335QP2
168
2.7600
0.2588
9.38
0.7246
5
TABLE X3.2Reproducibility Statistics
N OTE —No.=number of different salt spray cabinets in test program;R =95%reproduciblity limits,g;Cv =S R /avg,coefficient of variation,%;and S R =reproducibility standard deviation,g.
Materials Test Dura-tion,h Average Mass Loss,g S R ,g C v,%R ,g No.QP1480.81700.094711.580.265212QP196 1.53470.201914.020.565312QP1168 2.59960.325512.520.911412AP 480.77870.080510.330.225410AP 96 1.40940.162611.540.455310AP 168 2.43090.340214.000.952610QP2480.85660.152917.850.42815QP296 1.57200.13198.390.36935
QP2
168
2.7600
0.3873
14.03
1.0844
5
本标准规定了中性盐雾试验所使用的设备、试剂和方法。 本标准用于评定金属覆盖层的抗盐雾腐蚀能力，也可用于同一覆盖层的工艺质量比较。由于影响覆盖层腐蚀的因素很多，单一的抗盐雾性能不能代替抗其他介质的性能。所以本标准获得的试验结果，不能作为被试覆盖层在所有使用环境中抗腐蚀性能的依据，也不能作为不同覆盖层在使用中抗腐蚀性能的对比依据。 本标准对于试样的类型、试验周期和试验结果的解释均不作规定，这些内容应由覆盖层或产品标准来提供。 本标准等效采用国际标准ISO 3768-1976《金属覆盖层中性盐雾试验（NSS试验）》。 1 试验溶液 1.1 将化学纯的氯化钠溶于蒸馏水或去离子水中，其浓度为50±5g/L。 1.2 用酸度计测量溶液的pH值，也可以用经酸度计校对过的精密pH试纸作为日常检测。溶液的pH值，可用化学纯的盐酸或氢氧化钠调整。使试验箱内盐雾收集液的pH值为6.5～7.2。 1.3 为避免喷嘴堵塞，溶液在使用之前必须过滤。 2 试验设备 2.1 用于制造试验设备的材料，必须抗盐雾腐蚀和不影响试验结果。 2.2 箱的容积不小于0.2m3，最好不小于0.4m3，聚积在箱顶的液滴不得落在试样上。箱子的形状和尺寸应使得箱内盐雾收集液符合5.2条规定。 2.3 要能保持箱内各个位置的温度达到5.1条规定。温度计和自动控温元件，距箱内壁不小于100mm，并能从箱外读数。 2.4 喷雾装置包括下列部分。 a.喷雾气源：压缩空气经除油净化，进入装有蒸馏水，其温度高于箱内温度数度的饱和塔而被湿化。通过控压阀，使干净湿化的气源压力控制在70～170kpa(0.7～1.7kgf/cm2)范围内； B.喷雾室：由喷雾器、盐水槽和挡板组成，喷雾器可用1个或多个，由试验区的大小而定。挡板可防止盐雾直接喷射在试样上。喷雾器和挡板放置的位置，对盐雾的分布有影响； C.盐水贮槽：要有维持喷雾室内盐水槽一定液位的装置。 注：调节喷雾压力、饱和塔内水温和挡板的位置，使箱内盐雾沉降的速度和盐雾收集液氯化钠的浓度，达到5.2条的规定值。 2.5 盐雾收集器，由直径为10mm的漏斗插入带有刻度的容器所组成。其收集面积约80cm2。箱内至少放2个收集器，一个靠近喷嘴；一个远离喷嘴。要求收集的只是盐雾，而不是从试样或其他部位滴下的液体。 2.6 如果试验箱已作过不同于本规定的溶液的试验时，在使用前必须充分清洗。 3 试样 3.1 试样的类型、数量、形状和尺寸，应根据被试覆盖层或产品标准的要求而定。若无标准，可同有关方面协商决定。 3.2 试验前试样必须充分清洗，清洗方法视试样表面状况和污物性质而定。不能使用会浸蚀试样表面的磨料和溶剂。试样洗净后，必须避免沾污。 3.3 如果试样是从工件上切割下来的，不能损坏切割区附近的覆盖层。除另有规定外，必须用适当的覆盖层，如：油漆、石蜡或粘结胶带等，对切割区进行保护。 4 试样放置 4.1 试样放在试验箱内，被试面朝上，让盐雾自由沉降在被试面上，被试面不能受到盐雾的直接喷射。 4.2 试样放置的角度是重要的。平板试样的被试面与垂直方向成15°～30°，并尽可能成20°。表面不规则的试样(如整个工件)，也应尽可能接近上述规定。 4.3 试样不能接触箱体，也不能相互接触。试样之间的距离应不影响盐雾自由降落在被试面
打开机器电源(图1) 设定进气压力(图2) 4.3设定饱和桶温度，中性和醋酸盐雾试验饱和桶温度控制器设定为 47℃（40℃--50℃）；铜 加速盐雾试验饱和桶温度控制器设定为 63℃（60℃--70℃）（如图3）。 4.4设定试验箱温度，醋酸和中性盐雾试验，实验箱温度控制设定为35℃；铜加速盐雾试验，试验箱温度控制器设定为50℃（如图4）
设定饱和桶温度—47度 (图3) 设定试验箱温度—35度(图4) 设定测试时间，根据试验要求设定喷雾周期，如24、48、72、96即一个周期为24 个周期为48小时依次递增（如图 设定喷雾压力；喷雾压力为0.05～0.12MPa(6)。 设定测试时间(图5) 设定喷雾压力 (图6) 测试样品的放置，试样主要表面与铅垂线成15度至30度倾斜，并与盐雾箱内流动的主要方向平行，同时试样放置应能使盐雾在试样上自由地沉降，一个试样上的盐溶液不得落在任何其他试样上，样品与样品之间的距离不小于30mm（如图7)。 打开喷雾开关，测试开始（如图8) 测试完成关掉喷雾开关，打开除雾键，待试验箱雾除尽后，打开试验箱查看样品变化
测试中样品放置(图7) 打开喷雾开关，测试开始（图8) 测试完成关掉喷雾开关，打开除雾键9) 关闭机器电源(图10) 、试验液的配制 5.1氯化钠溶液配制（中性盐雾） 5.1.1将蒸馏水或纯水（去离子）倒入刻度筒中，体积为9.5升，将电导仪的两接头插入水中， 当指针未发生偏移时则确认水为合格。 5.1.2用天平称量0.5±0.1kg氯化钠，氯化钠要求为分析纯，NaI的含量要小于0.1% 纯物中可能含有腐蚀成份，所以不纯物含量不应超过0.3%。 5.1.3将NaCl放入水中，并用干净的玻璃棒轻轻搅动直至全部溶解。
盐雾试验标准及试验结果的判定方法 标准是对重复性事物和概述所做的统一规定。盐雾试验标准是对盐雾试验条件，如温度、湿度、氯化钠溶液浓度和PH值等做的明确具体规定，另外还对盐雾试验箱性能提出技术要求。同种产品采用那种盐雾试验标准要根据盐雾试验的特性和金属的腐蚀速度及对盐雾的敏感程度选择。下面介绍几个盐雾试验标准，如GB/T2423.17—1993《电工电子产品基本环境试验规程试验Ka：盐雾试验方法》，GB/T2423.18—2000《电工电子产品环境试验第2部分：试验：盐雾，交变(氯化钠溶液)》，GB5938—86《轻工产品金属镀层和化学处理层的耐腐蚀试验方法》，GB/T1771—91《色漆和清漆耐中性盐雾性能的测定》。 盐雾试验的目的是为了考核产品或金属材料的耐盐雾腐蚀质量，而盐雾试验结果判定正是对产品质量的宣判，它的判定结果是否正确合理，是正确衡量产品或金属抗盐雾腐蚀质量的关键。盐雾试验结果的判定方法有：评级判定法、称重判定法、腐蚀物出现判定法、腐蚀数据统计分析法。评级判定法是把腐蚀面积与总面积之比的百分数按一定的方法划分成几个级别，以某一个级别作为合格判定依据，它适合平板样品进行评价。 称重判定法是通过对腐蚀试验前后样品的重量进行称重的方法，计算出受腐蚀损失的重量来对样品耐腐蚀质量进行评判，它特别适用于对某种金属耐腐蚀质量进行考核; 腐蚀物出现判定法是一种定性的判定法，它以盐雾腐蚀试验后，产品是否产生腐蚀现象来对样品进行判定，一般产品标准中大多采用此方法; 腐蚀数据统计分析方法提供了设计腐蚀试验、分析腐蚀数据、确定腐蚀数据的置信度的方法，它主要用于分析、统计腐蚀情况，而不是具体用于某一具体产品的质量判定。 盐雾试验有中性盐雾试验N SS、醋酸盐雾AA SS和铜加速醋酸盐雾CASS、也称氯化铜醋酸盐雾试验三种,其中应用最广的是中性盐雾试验。盐雾试验基本内容是在35摄氏度下，5%的氯化钠水溶液，在试验箱内喷雾，模拟海水环境的加速腐蚀方法，其耐受时间的长短决定耐腐蚀性能的好坏。盐雾箱容积不小于012m 3、最好不小于014 m3、箱内温度35℃±2℃、喷雾压力70～170kPa、盐雾收集器至少两个、收集面积各80 cm2.被试面与垂直方向成15～30°让盐雾自由沉降在被测面上、不能直接喷射、试验支架用玻璃、塑料制造、试件不能相互接触、互相滴液;箱内温度35℃±2℃、每个收集器收集溶液1～2mL?h。
盐雾测试标准Newly compiled on November 23, 2020
表面处理用中性盐雾试验作业指导书1.适用范围:本标准规定为各项金属底材于电镀后、有机或无机涂装后等各项表面处理用之盐水喷雾耐触性试验方法. 2.试验方法:本法是使用盐水喷雾试验机将氯化纳溶液,以雾状喷于被覆膜上之一种腐蚀试验方法.试验的主要条件如表1所示. 表1 主要的试验条件 表2 连续雾化时间表 3.试验液之配制:溶解氯化纳(化学纯、分析纯）于蒸馏水（或总溶解固体量小于200 ppm以下的水中）, 调配成浓度为5±%的试验液.此试验液在35℃喷雾后,其收集液PH值应为~.且喷雾前,此试验液不能含有浮态物. 注（1）氯化钠不能含有铜兴镍的不纯物,固体内的碘化钠含量小于%.因为不纯物中可能含有腐蚀抑制剂,所以不纯物总含量须小于% . （2）在33~35℃间测量比试验液的比重应为~,在25℃测量时的比重则为~.此试验液的浓度亦可用硝酸银液滴定法或其它方法检定. （3）试验液须以试药级的盐酸或氢氧化钠稀溶液调整PH值,并以PH仪或其它可靠方法测量之,由于配制试验液的水中含有二氧化碳,二氧化碳在水中的溶解度随温度改变而影响溶液的PH值, 故须小心控制PH值,PH值则可依下列任一方法调整:
①常温配制试验液,于35℃喷雾,因为温度的升高而使部份二氧化碳逸出溶液而升高PH值.故在 常温配制试验液时,PH值应调整在内,才可以使收集液的PH值在~之间. ②PH值调整前,使试验液先煮沸再冷至35℃,或维持在35℃温度48小时.如此调整的PH值在喷 雾时,将不会产生太大的变化. ③先将水加热至35℃以上,以去除溶解的二氧化碳,而后再调制试验液并调整PH值,如此在 35℃喷雾时,所调整的PH值也不会产生太大的变化. （4）为避免喷雾嘴阻塞,此试验液须过滤或小心倾斜注入盐水桶,或于喷雾吸水管前端处装上玻璃筛过滤,盐雾测试仪每工作2000小时,需更换玻璃喷嘴. 4.设备:本试验所需之设备为喷雾嘴、盐水桶、试验片支架、喷雾液收集容器、试验室、盐水[补给桶、 压力桶、压缩空气之供给设备与排气设备等所构成,其装置如图1所示,并依照如下条件试验. 盐水喷雾试验机与其所需的管路应采用钝性材料,不能对喷雾之腐蚀试验有影响或本身被腐蚀者. 喷雾嘴不可直接将试验液喷向试样,喷雾室顶部聚集之溶液不得滴落在试验片上. 试验片滴下之试验液不可流回盐水桶,而再用于试验. 压缩空气不能含有油脂及灰尘,所以须有空气清净器.空气压力须保持在±cm2,因为压缩空气于膨胀时,有吸热现象,所以须事先有预热以增加压缩空气的温度与湿度,如附表2,以获取均一温度的喷雾. 喷雾采取器其水平采取面积为80cm2,直径约为10 cm,置于试验片附近（靠近喷嘴最近与最远之处的两个地方）. 喷雾液量以整个时间计算,在采取容器上,应每小时平均可收集至之盐水溶液.喷雾液至少应收集16小时,以其平均值表不喷雾量. 试验中盐水桶,其氯化钠溶液浓度应维持40~60g/L,试验用盐液在1星期内没用完时,需作更换,如下次试验时间超过1星期时,需将试验室内部清洗,将试验盐液,加热水槽之水排出. 压力桶之温度须保持在47±1℃,盐水桶之温度在35±1℃. 试验室的相对湿度须保持在85%以上,更高的相对湿度的要求可与客户双方协议确定. 实验工作中,实验盖边口有实验雾气漏出时,需向密封水槽内加水,试验期间如超过1个月,需将热水槽内水更换. 5.试样 采取位置:试样可从制品之主要表面采取或以制品本身做为试样.但如无法以制品试验或判定时,可以用试验片代替且此试验片必须能代表被测试制品. 尺度:试验片之标准尺寸为150×70mm,或为100×65mm. 数目:试样之数目3-5PCS. 试验前处理 5.4.1试样依镀层性质与清洁程度而须做适当清洗,不能使研磨剂及具有腐蚀或抑制作用之溶剂清洗, 且清洗方法不得损伤表面.至于不锈钢试样使用硝酸清洗与钝化,试样经清净后(通过拔水性试 验),以干净之布或吸水将水份擦干,或用无油之干燥空气吹干.不得已时,可使用氧化镁膏.此膏 状物乃10g试药级氧化镁加入100mL的蒸馏水中. 5.4.2 若非另有规定,否则试样切口及因挂色而造成底材露出部份,或因识别记号所造成镀层缺陷处 于试验时应覆以合适之保护层.如硬蜡(ceresin wax),乙烯胶带等绝缘物. 5.4.3 手纹污染会造成严重的不良试验结果,试样于清净后不得有任何手纹的污染. 6.试样之置放:试验中,试验室内之试样的位置符合以下列条件: 试样之主要表面与铅垂线成15度至30度之倾斜,又自试验室上方俯视时应与喷雾之主要流动方向平行. 特殊零件具有很多方向的主要表面,需要同时测试时,可取多件试样置放,务必使每个主要表面能同时接受盐水的喷雾. 试样之排列,应使喷雾自由地落至全部试片上,不应防碍喷雾之自由落下. 试样不可互相接触,也不可接触到金属性导体或有毛细现象作用之物质,以及其它支持架以外之物. 盐水溶液勿从一个试样滴流至其它试样上.
名称ASTM-B117-09 盐雾试验标准 本标准已被批准供国防部下述机构使用。 1、使用范围 1.1本标准规程包括产生和维持盐雾实验环境所要求的仪器和程序，可能用到的合适的仪器在附录X1里说明。 1.2本规程并不指定试验的样本类型，或特殊产品的喷雾时间，也不对试验结果作出解释。 1.3以SI为单位的数据是标准的，括号内的数据仅供参考。 1.4本标准并不旨在涵盖所有的安全性问题，如果有，也是与它的使用方法有关系。本标准的使用者有责任来建立合适的安全及健康操作程序，并在使用前决定规程限制的适用性。 2、参考文献 2.1 ASTM标准2 B368 用以加速铜腐蚀的醋酸-盐雾试验方法（CASS试验） D609 测试冷扎钢板喷涂、清漆、化学涂层和其他相关涂层产品的制剂 D1193 试剂水说明 D1654 在腐蚀环境下，样本喷涂估算的试验方法 E70 玻璃电极水溶液PH值的试验方法 E691 开展实验室间研究，以确定试验方法精密度的规程 G85 更新的盐雾试验规程 3、意义及作用 3.1本规程提供了一种可控的腐蚀环境，金属及涂装金属在给定的试验房间里产生相关的防腐蚀信息。 3.2在自然环境下对其性能的预测值，与单独作为数据的盐雾试验结果很少有关联。 3.2.1建立在这种规程试验环境下，其腐蚀性能的关联值和外延值并不总是可预测的。 3.2.2只有在证实进行了适宜的长期自然环境的暴露以后，才应当考虑关联值和外延值。 3.3盐雾试验结果的可重复性，在很大程度上依赖于试验的样品和所选择的标准，也依赖于对操作变量的控制。在一些测试程序中，应当考虑到大量的数据采集次数，以建立试验结果的可变性。即使试验条件相似，测试的浓度范围一样，在不同的盐雾实验室内，相似的样本其试验结果也不一样。 4、装置 4.1盐雾试验所要求的装置，包括一个盐雾室，盐溶液储罐、适当的压缩空气供应装置、一个或多个喷嘴、样品支撑架、盐雾室加热装置和其他必要的控制部件。装置的尺寸和详细的结构是可选择的，只要能提供本规程所要求的环境即可。 4.2盐雾室内顶部或盖板上聚集的液滴不允许滴落在暴露的样本上。 4.3从样本上滴落的液滴不允许回收到液体回收器内，不能再喷雾。 4.4盐雾室结构件材料不应当影响到喷雾腐蚀。 4.5本规程用到的所有的水都要符合D1193说明中5类水标准要求（钠离子可以忽略，氯离子在本规程的范围内即可），这不适用于自来水，所有其他的水要求相应的试剂等级。 5、试验样本 5.1 试验用的样本的型号和数量，和评估试验结果的标准一样，都要在说明中规定其材料或产品，或由销售
盐雾试验方法和判定标准 1.总则 1.1目的规范金属结构件的中性盐雾试验NSS 1.2适用该规范适用本公司所有金属结构件、紧固件、电器件等试验方法和判定标准。 1.3职责质量部主管负责测试报告的编制和测试结果的判定IQC负责产品的测试。 1.4实施文控受控发行之日正式实施。 2.引用标准 2.1 GB/T242 3.17-1993 电工电子产品基本环境试验规程试验Ka 2.2 GB/T 6461-2002金属基本体上金属和其它无机覆盖层经腐蚀试验后的式样和试件的评 级 3.试验设备本试验所需设备为喷雾嘴、盐水桶、试验片支援架、喷雾液收集容器、盐水补 给桶、压力桶、压缩空气之供给设备与排气设备等所构成,并依照如下条件试验。3.1 喷雾嘴不可直接将试验液喷向试样, 喷雾室顶部聚集的溶液不得滴落在试样上 3.2 试样滴落的试验液体不可再用于试验 3.3 压缩空气不可有油脂及灰尘, 须有空气清凈器 1.00.1kgf/cm2 预热以增加压缩空气的温度与湿度 压缩空气(Kpa) 84 98 111 126 压力(Kgf/cm2) 0.86 1.00 1.14 1.29 所需预热温度46 47 48 49 3.5 喷雾水平采取面积为80cm2, 直径约为10cm, 置于试样附近 3.6 喷雾液量以整个小时计算, 在采集容器上, 应每小时平均可收集1.6ml盐水溶液。喷 雾液至少应连续收集8小时, 以其平均值表示喷雾量 3.7 试验中盐水桶其氯化钠溶液浓度应维持40~60g/l。 4.试验条件 4.1试验溶液试验溶液采用氯化钠和蒸馏水（5 ±0.1%）（质量百分比） 雾化后的收集液，除挡板挡回部分外，不得重复使用； 4.2溶液PH值雾化前的盐溶液PH值在6.5-7.235±2℃ 4.3实验室内温度(指箱体内的温度) 35±2℃ 4.4饱和压力桶内温度47±1℃ 4.5饱和桶压力1Kgf 4.6喷雾量在工作空间任意位置80cm2的漏斗收集连续雾化8h的盐雾沉降 量 1.6mL的溶液 4.7连续雾化时间 NO. 材质表面处理方式连续雾化时间 1 铜镀镍12h 镀锡8h 先镀镍再镀锡24h 镀金24h 2 SPCC(冷轧钢板) 镀镍12h 镀锡8h 镀白锌24h 镀蓝白锌24h 镀彩锌24h
盐雾试验评级标准(2008/03/26 13:30) 目录：技术文章 浏览字体：大中小盐雾试验箱操作指导书 1. 目的 正确使用盐雾试验箱，以检测镀层的耐腐蚀性能。 2. 适用范围 可根据客户要求对电镀零件和产品进行盐雾试验。 3. 职责 3.1 质保部是电镀产品检验和试验的归口管理部门； 3.2 电镀检验人员负责对电镀产品进行盐雾试验的整个过程。 4. 操作程序 4.1设备: 经过鉴定符合有关标准的盐水喷雾试验机XXXXX 4.2盐雾试验溶液的配制: 4.2.1. 调制方法：将9.5公升的纯净水倒入专用的塑料桶中，用PH 试纸测试其PH值是否在6.5-7.2之间； 4.2.2. PH值若大于7.2则加入少量的冰醋酸； 4.2.3. PH值若小于6.5则加入少量的氢氧化钠； 4.2.4. 加入500g氯化钠NaCl，搅拌均匀。 4.3样品: 20个试样
4.4操作程序: 1. 将自动加水的入水口阀门排水阀和排气阀的开关打开。 2. 将隔绝水槽加水至垫板位置。 3. 将配制好的氯化钠盐水倒入到盐水补充槽，即自动充填盐水进入试验箱内的预热槽，使盐水流至盐水预热槽。 4. 加少许水在湿球杯内，湿球温度覆盖着纱布，纱布末端置于湿球杯内。 5. 开始试验前，试样必须充分清洗，清洗方法视表面情况及污物的性质而定，不能使用任何 会侵蚀试样表面的磨料或溶剂，同时试样切口及因挂钩而造成底材露出部分，或因识别记号所造成的镀层缺陷处，试验前应用透明胶带将以覆盖。放置试样或试片于置物架上，试样在箱内放置的位置，应使受试平板试样与垂直线成15-30°角，试样的主要表面向上，并与盐雾在箱内流动的主要方向平行。特殊试样有很多的主要表面需要同时测试时，可取多件试样置放，务必使每个主要表面能同时进行盐雾试验。 6. 试验时，试样之间不得互相接触，也不与箱壁相碰，试样的间距一般不小于20mm，试样上下层必须交叉放置，试样间间隔应能使盐雾自由沉降在试样的主要表面上。一个试样上的盐水溶液不得滴在任何别的试样上。试样识别记号或装配孔应覆于下方。 7. 设定试验温度、压力和时间： 将盐水桶和试验室的温度调整至35℃，压力桶温度调整至47℃（按“+”为增加，按“—”为减少，H：时/M：分/S：秒）。喷压压力保持在
盐雾测试操作规范 Prepared on 22 November 2020
1、目的 严格执行醋酸盐雾试验的操作，使之符合GBT10125-1997和GBT6461-2002的要求，排除人为因素对检测结果的影响。 2、范围 适用于铜基体的铜+镍+铬镀层，锌合金基体的铜+镍+铬镀层，钢铁基体的铜+镍+铬镀层。 适用于1所述镀层上作PVD处理的膜层。 适用于铝的阳极化层的耐腐蚀性试验。 装饰性有机涂层。 3、设备说明 盐水喷雾试验必要装置为喷雾室、盐水箱、压缩空气供给机、喷雾喷嘴、试验片支持器、喷雾室加热设备、调节装置。 喷雾嘴不可直接将试验液喷向试样，喷雾室外顶部聚集之溶液不得滴落在试样上。 试验片滴下的试验液不可流回盐水桶，而再用于试验。 装置材料不得对喷雾之腐蚀性有影响。 4、操作步骤 打开盐雾机电源（如图1）。 设定进气压力，将压力调至～之压力（如图2）。 打开机器电源(图1) 设定进气压力(图2) 设定饱和桶温度，中性和醋酸盐雾试验饱和桶温度控制器设定为 47℃（40℃--50℃）；铜加速盐雾试验饱和桶温度控制器设定为 63℃（60℃--70℃）（如图3）。 设定试验箱温度，醋酸和中性盐雾试验，实验箱温度控制设定为35℃；铜加速盐雾试验， 试验箱温度控制器设定为50℃（如图4）
设定饱和桶温度—47度 (图3) 设定试验箱温度—35度(图4) 设定测试时间，根据试验要求设定喷雾周期，如24、48、72、96即一个周期为24小时，2个周期为48小时依次递增（如图5）。 设定喷雾压力；喷雾压力为～(如图6)。 设定测试时间(图5) 设定喷雾压力 (图6) 测试样品的放置，试样主要表面与铅垂线成15度至30度倾斜，并与盐雾箱内流动的主要方向平行，同时试样放置应能使盐雾在试样上自由地沉降，一个试样上的盐溶液不得落在任何其他试样上，样品与样品之间的距离不小于30mm（如图7)。 打开喷雾开关，测试开始（如图8)。 测试完成关掉喷雾开关，打开除雾键，待试验箱雾除尽后，打开试验箱查看样品变化(如图9)。 .测试结束后，关闭电源开关（如图10）
盐雾试验判定标准 1. 盐雾试验判定标准 1．1 为了确保经过盐雾测试后产品抗盐雾腐蚀能力质量基本的判断，检查方法的正确性；1．2 本标准用于考核材料及其防护层的抗盐雾腐蚀能力，以及相似防护层的工艺质量比较，也可用来考核某些产品抗盐雾腐蚀能力； 1．3 本标准不作为通用的腐蚀试验方法； 1．4 本标准是参照国家标准GB6461；GB12335，GB/T9798 1997的附录（eqvISO1462.1973）中性盐雾试验标准(NSS)编写； 2. 适用范围： 2．1 对电镀零件和可用于盐雾实验的产品进行测试后，检查方法及判断； 2．2 测定面腐蚀状况测定，也可由买卖双方事先协定之方法判定之； 3. 检验方法： 3．1 试验结果的评价: a 试验后的外观； b 除去表面腐蚀产物后的外观； c 腐蚀缺陷如点蚀、裂纹、气泡等的分布和数量和状态； d 被腐蚀时间； 3．2 评级原则： 1 对镀件外观或使用性能起重要作用的部分镀层表面，即主要表面进行外观和保护等级评定。 2 试样检查结果用（/）把两种等级分别记录，保护等级记录在第一位。 3 除记录试样的级别外，还应注明评级的缺陷种类和严重程度。 3．3 缺陷的类型： 1 保护缺陷包括凹坑腐蚀、针孔腐蚀、鼓泡、腐蚀产物以及金属腐蚀产物的其他缺 陷； 2 外观缺陷除了因底材金属引起的缺陷外，还包括试样外观所有的损坏。典型的缺 陷油；表面麻点、“鸡爪状”缺陷、开裂、表面沾污和失去光泽； 3．4 保护等级（Rp）的评定 根据腐蚀缺陷所覆盖的面积按以下的计算方法得出保护等级；像镀锌等对底材呈阳性的电镀层，其表面的外观变化包括变色、失光，覆盖层腐蚀和基体金属腐蚀等；把其产生的各种变化分成A~I等共9个级别，各级外观的变化如下表所示。对镀层的评级可参照表中所列现象进行评定。 3．4．1等级与外观 外观评级样品表面外观的变化 A级无变化 B级轻微到中度的变色 C级严重变色或极轻微的失光 D级轻微的失光或出现极轻微的腐蚀产物 E级严重失光，或试样表面局部有薄层的腐蚀产物或点蚀
ASTM B117 －2011：操作盐雾测试机1 的标准实验方法 本标准是在以固定称呼B117 来发行，而跟随在称呼之后的数字则表示为最早发行之年版或是最后发行年版，括号内之号码则表示该版本经确认之最后年版，如果后面又加上括号内并含一希腊字母时则代表在最后版本确认后还有编辑上的修改。本标准已由国防部核准使用。 1. 范围 本实验方法包含了仪器、程序以及为了建立与保持盐水喷雾试验环境所要求之条件。附录X1描述可被使用之适合的试验机。 本实验没有指定试验样品的种类或者对于特定产品所需的曝露时间，也不对结果作说明。以SI(国际公制单位)数据单位来表示被视为标准。英寸-磅单位以括号表示是为了提供资讯且可能是相等的。 本标准并未指明试验方法上所产生之任何安全问题，该安全问题是引用本标准之使用者的责任。使用者应自行建立适当之安全卫生操作方法，并且在使用前决定应有的使用限制规定。 2. 参考文件 ASTM 标准 B 368－醋酸铜盐水喷雾试验方法(CACC试验) . D 1193－试剂水4(Reagent Water)的规范. D 1654－涂漆或有镀层的试片在腐蚀环境3下之评估方法. E 70－使用玻璃电极5量测含水溶液的pH值之试验方法. E 691－决定试验方法的正确性6. G 85－修正盐水喷雾试验的实验7 3. 重要性以及使用 本实验提供一个受控制之腐蚀环境，该环境被利用来让金属与镀金属的试件暴露于一特定试验室中而产生相关防腐蚀的讯息。 当使用独立的数据时，在自然环境中试验的预估很少与盐水喷雾的结果有所关连。 基于暴露于本实验所提供的试验环境，腐蚀发生的关系与推测并不常是可预料的。 只有在适当的确定长期环境暴露已被采用时，相互关系与推测应被考虑。 2/15 暴露于盐水喷雾结果的再现性是高度取决于试验试件的种类所选择的评估准则，以及操作变异的控制。在任何试验程序中，在建立结果的变异应包括充分的复制。当类似的试件于不同的雾室中试验，即使试验条件是大约相同且介于本实验所规定的范围内，还是有可能发觉其变异性。 4. 仪器
盐雾测试操作规范 The manuscript was revised on the evening of 2021
1、目的 严格执行醋酸盐雾试验的操作，使之符合GBT10125-1997和GBT6461-2002的要求，排除人为因素对检测结果的影响。 2、范围 适用于铜基体的铜+镍+铬镀层，锌合金基体的铜+镍+铬镀层，钢铁基体的铜+镍+铬镀层。 适用于1所述镀层上作PVD处理的膜层。 适用于铝的阳极化层的耐腐蚀性试验。 装饰性有机涂层。 3、设备说明 盐水喷雾试验必要装置为喷雾室、盐水箱、压缩空气供给机、喷雾喷嘴、试验片支持器、喷雾室加热设备、调节装置。 喷雾嘴不可直接将试验液喷向试样，喷雾室外顶部聚集之溶液不得滴落在试样上。 试验片滴下的试验液不可流回盐水桶，而再用于试验。 装置材料不得对喷雾之腐蚀性有影响。 4、操作步骤 打开盐雾机电源（如图1）。 设定进气压力，将压力调至～之压力（如图2）。 打开机器电源(图1) 设定进气压力(图2) 设定饱和桶温度，中性和醋酸盐雾试验饱和桶温度控制器设定为 47℃（40℃--50℃）；铜加速盐雾试验饱和桶温度控制器设定为 63℃（60℃--70℃）（如图3）。 设定试验箱温度，醋酸和中性盐雾试验，实验箱温度控制设定为35℃；铜加速盐雾试验， 试验箱温度控制器设定为50℃（如图4）
设定饱和桶温度—47度 (图3) 设定试验箱温度—35度(图4) 设定测试时间，根据试验要求设定喷雾周期，如24、48、72、96即一个周期为24小时，2个周期为48小时依次递增（如图5）。 设定喷雾压力；喷雾压力为～(如图6)。 设定测试时间(图5) 设定喷雾压力 (图6) 测试样品的放置，试样主要表面与铅垂线成15度至30度倾斜，并与盐雾箱内流动的主要方向平行，同时试样放置应能使盐雾在试样上自由地沉降，一个试样上的盐溶液不得落在任何其他试样上，样品与样品之间的距离不小于30mm（如图7)。 打开喷雾开关，测试开始（如图8)。 测试完成关掉喷雾开关，打开除雾键，待试验箱雾除尽后，打开试验箱查看样品变化(如图9)。 .测试结束后，关闭电源开关（如图10）
盐雾测试 盐雾试验与实际情况的关系 一、盐雾的腐蚀 腐蚀是材料或其性能在环境的作用下引起的破坏或变质。大多数的腐蚀发生在大气环境中，大气中含有氧气、湿度、温度变化和污染物等腐蚀成分和腐蚀因素。盐雾腐蚀就是一种常见和最有破坏性的大气腐蚀。这里讲的盐雾是指氯化物的大气，它的主要腐蚀成分是海洋中的氯化物盐——氯化钠，它主要来源于海洋和内地盐碱地区。盐雾对金属材料表面的腐蚀是由于含有的氯离子穿透金属表面的氧化层和防护层与 内部金属发生电化学反应引起的。同时，氯离子含有一定的水合能，易被吸附在金属表面的孔隙、裂缝排挤并取代氯化层中的氧，把不溶性的氧化物变成可溶性的氯化物，使钝化态表面变成活泼表面。造成对产品极坏的不良反应。 二、盐雾试验及与实际的联系 盐雾试验是一种主要利用盐雾试验设备所创造的人工模拟盐雾环境条件来考核 产品或金属材料耐腐蚀性能的环境试验。它分为二大类，一类为天然环境暴露试验，另一类为人工加速模拟盐雾环境试验。人工模拟盐雾环境试验是利用一种具有一定容积空间的试验设备——盐雾试验箱，在其容积空间内用人工的方法，造成盐雾环境来对产品的耐盐雾腐蚀性能质量进行考核。它与天然环境相比，其盐雾环境的氯化物的盐浓度，可以是一般天然环境盐雾含量的几倍或几十倍，使腐蚀速度大大提高，对产品进行盐雾试验，得出结果的时间也大大缩短。如在天然暴露环境下对某产品样品进行试验，待其腐蚀可能要1年，而在人工模拟盐雾环境条件下试验，只要24小时，即可得到相似的结果。 人工模拟盐雾试验又包括中性盐雾试验、醋酸盐雾试验、铜盐加速醋酸盐雾试验、交变盐雾试验。 (1) 中性盐雾试验（NSS试验）是出现最早目前应用领域最广的一种加速腐蚀试验方法。它采用5%的氯化钠盐水溶液，溶液PH值调在中性范围（6～7）作为喷雾用的溶液。试验温度均取35℃，要求盐雾的沉降率在1～2ml/80cm2.h之间。 (2) 醋酸盐雾试验（ASS试验）是在中性盐雾试验的基础上发展起来的。它是在5%氯化钠溶液中加入一些冰醋酸，使溶液的PH值降为3左右，溶液变成酸性，最后形成的盐雾也由中性盐雾变成酸性。它的腐蚀速度要比NSS试验快3倍左右。 (3) 铜盐加速醋酸盐雾试验（CASS试验）是国外新近发展起来的一种快速盐雾腐蚀试验，试验温度为50℃，盐溶液中加入少量铜盐—氯化铜，强烈诱发腐蚀。它的腐蚀速度大约是NSS试验的8倍。 (4) 交变盐雾试验是一种综合盐雾试验，它实际上是中性盐雾试验加恒定湿热试验。它主要用于空腔型的整机产品，通过潮态环境的渗透，使盐雾腐蚀不但在产品表面产生，也在产品内部产生。它是将产品在盐雾和湿热两种环境条件下交替转换，最后考核整机产品的电性能和机械性能有无变化。 三、盐雾试验标准及试验结果的判定
盐雾试验方法和判定标准 目录索引 1.总则 (1) 2.引用标准 (2) 3.试验设备 (2) 4.试验条件 (3) 5.试件的放置 (4) 6.试件的初始检测 (4) 7.试件的预处理 (4) 8.试验程序 (5) 9.试验完成后的试样处理 (5) 10.最终检测 (5) 11.试验结果的判定 (5) 13.对照图片参考 (7) 13.图片对照参考 8
1.总则 1.1目的 为规范金属结构件的中性盐雾试验（NSS）的方法和判定标准而制定本规范。 1.2适用 该规范适用本公司所有金属结构件和紧固件的试验方法和判定标准。 1.3职责 1.3.1 IQC负责提出测试申请和提供测试样品； 1.3.2试验员负责根据样品材质和表面处理方式制定测试方案，并负责实施。 1.3.3试验员负责测试报告的编制和测试结果的判定。 1.3.4品质工程师负责报告的审核和最终判定。 2.引用标准 2.1 GB/T10125-1997 人造气氛腐蚀试验，盐雾试验； 2.2 QC/T625-1999 汽车用涂镀层和化学处理层； 2.3 GB/T5267.1-2002 紧固件电镀层； 2.4ISO14993-2001 Corrosion of metals and alloys——accelerated testing involving cyclic exposure to salt mist,” dry” and “wet”condition； 3.试验设备 本试验所需设备为喷雾嘴、盐水桶、试验片支援架、喷雾液收集容器、试验室（1）、 盐水补给桶、压力桶、压缩空气之供给设备与排气设备等所构成 ,并依照如下条件试验。 注（1）：试验室大小, 须在0.48m3以上。 3.1盐水喷雾试验机与其所需的管路应采用纯性材料, 不能对喷雾腐蚀试验有影响或本身 被腐蚀者； 3.2 喷雾嘴不可直接将试验液喷向试样, 喷雾室顶部聚集的溶液不得滴落在试样上； 3.3 试样滴落的试验液体不可流回盐水桶而再用于试验； 3.4 压缩空气不能含有油脂及灰尘；空气压力须保持在1.00.1kgf/cm2 因为压缩空气于膨胀时, 有吸热现象, 所以须事先有预热（2）如下附表,以获取均一温度的喷雾。 注（2）：预热以增加压缩空气的温度与湿度； 压缩空气(Kpa)8498111126压力(Kgf/cm2)0.86 1.00 1.14 1.29
？ 表面处理用中性盐雾试验作业指导书 1.适用范围:本标准规定为各项金属底材于电镀后、有机或无机涂装后等各项表面处理用之盐水喷雾耐触性试验方法. 2.试验方法:本法是使用盐水喷雾试验机将氯化纳溶液,以雾状喷于被覆膜上之一种腐蚀试验方法.试验的主要条件如表1所示. 表1 主要的试验条件 表2 连续雾化时间表
3.试验液之配制:溶解氯化纳(化学纯、分析纯）于蒸馏水（或总溶解固体量小于200 ppm以下的水中）,调配成浓度为5 ±%的试验液.此试验液在35℃喷雾后,其收集液PH值应为~.且喷雾前,此试验液不能含有浮态物. 注（1）氯化钠不能含有铜兴镍的不纯物,固体内的碘化钠含量小于%.因为不纯物中可能含有腐蚀抑制剂,所以不纯物总含量须小于% . （2）在33~35℃间测量比试验液的比重应为~,在25℃测量时的比重则为~.此试验液的浓度亦可用硝酸银液滴定法或其它方法检定. （3）试验液须以试药级的盐酸或氢氧化钠稀溶液调整PH值,并以PH仪或其它可靠方法测量之,由于配制试验液的水中含有二氧化碳,二氧化碳在水中的溶解度随温度改变而影响溶液的PH值,故须小心控制PH值,PH值则可依下列任一方法调整: ①常温配制试验液,于35℃喷雾,因为温度的升高而使部份二氧化碳逸出溶液而升高PH值.故在常温配制试验液 时,PH值应调整在内,才可以使收集液的PH值在~之间. ②PH值调整前,使试验液先煮沸再冷至35℃,或维持在35℃温度48小时.如此调整的PH值在喷雾时,将不会产生 太大的变化. \ ③先将水加热至35℃以上,以去除溶解的二氧化碳,而后再调制试验液并调整PH值,如此在35℃喷雾时,所调整的 PH值也不会产生太大的变化. （4）为避免喷雾嘴阻塞,此试验液须过滤或小心倾斜注入盐水桶,或于喷雾吸水管前端处装上玻璃筛过滤,盐雾测试仪每工作2000小时,需更换玻璃喷嘴. 4.设备:本试验所需之设备为喷雾嘴、盐水桶、试验片支架、喷雾液收集容器、试验室、盐水[补给桶、压力桶、压缩空气 之供给设备与排气设备等所构成,其装置如图1所示,并依照如下条件试验. 盐水喷雾试验机与其所需的管路应采用钝性材料,不能对喷雾之腐蚀试验有影响或本身被腐蚀者. 喷雾嘴不可直接将试验液喷向试样,喷雾室顶部聚集之溶液不得滴落在试验片上. 试验片滴下之试验液不可流回盐水桶,而再用于试验. 压缩空气不能含有油脂及灰尘,所以须有空气清净器.空气压力须保持在±cm2,因为压缩空气于膨胀时,有吸热现象,所以须事先有预热以增加压缩空气的温度与湿度,如附表2,以获取均一温度的喷雾. 喷雾采取器其水平采取面积为80cm2,直径约为10 cm,置于试验片附近（靠近喷嘴最近与最远之处的两个地方）. { 喷雾液量以整个时间计算,在采取容器上,应每小时平均可收集至之盐水溶液.喷雾液至少应收集16小时,以其平均值表不喷雾量. 试验中盐水桶,其氯化钠溶液浓度应维持40~60g/L,试验用盐液在1星期内没用完时,需作更换,如下次试验时间超过1星期时,需将试验室内部清洗,将试验盐液,加热水槽之水排出. 压力桶之温度须保持在47±1℃,盐水桶之温度在35±1℃. 试验室的相对湿度须保持在85%以上,更高的相对湿度的要求可与客户双方协议确定. 实验工作中,实验盖边口有实验雾气漏出时,需向密封水槽内加水,试验期间如超过1个月,需将热水槽内水更换. 5.试样 采取位置:试样可从制品之主要表面采取或以制品本身做为试样.但如无法以制品试验或判定时,可以用试验片代替且此试验片必须能代表被测试制品. 尺度:试验片之标准尺寸为150×70mm,或为100×65mm.
盐雾试验箱安全操作规程 一、开机 接通烟雾机的外供电源和气源→检查压力桶和试验箱排水阀是否关闭、检查进气压力表是否达到2Kg→开启烟雾机操作面板上电源、操作开关→观察控制版面指示是否有低水位和低盐水亮红灯及报警声→出现时要进行加水和加盐水来消除亮灯及报警故障（溶解试药级氯化钠于蒸馏水（或总溶解固体量小于200ppm以下的水中），调配成浓度为5±1%的试验液）→将需测试物品放置到试验箱内（试样之主要表面与铅垂线成15度至30度之倾斜）、同时调整试验产品需测试时间→调整计时器→开启控制版面计时开关、开启喷雾开关→控制版面压力表迅速动作（喷雾压力需设定为1Kg）→盐雾机喷雾工作开始； 二、设备运行 设备运行时：保障电源、水源、气源正常； 设备运行时：压力桶之温度须保持在47±1℃，盐水桶之温度在35±1℃； 设备运行时：试验室的相对温度须保持在85%； 设备运行时：喷雾液量以整个时间计算，在采取容器上，应每小时平均可收集1.0至2.0ml之盐水溶液。喷雾液至少应收集16小时，以其平均值表求喷雾量。 三、其他 停机：先关闭控制版面喷雾开关→开启除雾开关、待实
验箱雾出除干净后才能打开实验箱盖； 保养：每月清洗一次压力桶、实验箱、盐水桶及喷嘴；1周以上时间停用机器需全面清洗干净；（喷嘴拆卸时要轻拿轻放，并用清水冲洗干净） 盐雾试验箱安全操作规程 四、开机 接通烟雾机的外供电源和气源→检查压力桶和试验箱排水阀是否关闭、检查进气压力表是否达到2Kg→开启烟雾机操作面板上电源、操作开关→观察控制版面指示是否有低水位和低盐水亮红灯及报警声→出现时要进行加水和加盐水来消除亮灯及报警故障（溶解试药级氯化钠于蒸馏水（或总溶解固体量小于200ppm以下的水中），调配成浓度为5±1%的试验液）→将需测试物品放置到试验箱内（试样之主要表面与铅垂线成15度至30度之倾斜）、同时调整试验产品需测试时间→调整计时器→开启控制版面计时开关、开启喷雾开关→控制版面压力表迅速动作（喷雾压力需设定为1Kg）→盐雾机喷雾工作开始； 五、设备运行 设备运行时：保障电源、水源、气源正常； 设备运行时：压力桶之温度须保持在47±1℃，盐水桶之温度在35±1℃；
盐雾测试 Salt Fog Test 盐雾试验与实际情况的关系 一、盐雾的腐蚀 腐蚀是材料或其性能在环境的作用下引起的破坏或变质。大多数的腐蚀发生在大气环境中，大气中含有氧气、湿度、温度变化和污染物等腐蚀成分和腐蚀因素。盐雾腐蚀就是一种常见和最有破坏性的大气腐蚀。这里讲的盐雾是指氯化物的大气，它的主要腐蚀成分是海洋中的氯化物盐—氯化钠，它主要来源于海洋和内地盐碱地区。盐雾对金属材料表面的腐蚀是由于含有的氯离子穿透金属表面的氧化层和防护层与内部金属发生电化学反应引起的。同时，氯离子含有一定的水合能，易被吸附在金属表面的孔隙、裂缝排挤并取代氯化层中的氧，把不溶性的氧化物变成可溶性的氯化物，使钝化态表面变成活泼表面。造成对产品极坏的不良反应。 二、盐雾试验及与实际的联系 盐雾试验是一种主要利用盐雾试验设备所创造的人工模拟盐雾环境条件来考核产品或金属材料耐腐蚀性能的环境试验。它分为二大类，一类为天然环境暴露试验，另一类为人工加速模拟盐雾环境试验。人工模拟盐雾环境试验是利用一种具有一定容积空间的试验设备—盐雾试验箱，在其容积空间内用人工的方法，造成盐雾环境来对产品的耐盐雾腐蚀性能质量进行考核。它与天然环境相比，其盐雾环境的氯化物的盐浓度，可以是一般天然环境盐雾含量的几倍或几十倍，使腐蚀速度大大提高，对产品进行盐雾试验，得出结果的时间也大大缩短。如在天然暴露环境下对某产品样品进行试验，待其腐蚀可能要1年，而在人工模拟盐雾环境条件下试验，只要24小时，即可得到相似的结果。 人工模拟盐雾试验又包括中性盐雾试验、醋酸盐雾试验、铜盐加速醋酸盐雾试验、交变盐雾试验。 (1) 中性盐雾试验（NSS试验）是出现最早目前应用领域最广的一种加速腐蚀试验方法。它采用5% 的氯化钠盐水溶液，溶液PH值调在中性范围（6～7）作为喷雾用的溶液。试验温度均取35℃，要求盐雾的沉降率在1～2ml/80cm2.h之间。 (2) 醋酸盐雾试验（ASS试验）是在中性盐雾试验的基础上发展起来的。它是在5%氯化钠溶液中加 入一些冰醋酸，使溶液的PH值降为3左右，溶液变成酸性，最后形成的盐雾也由中性盐雾变成酸性。它的腐蚀速度要比NSS试验快3倍左右。 (3) 铜盐加速醋酸盐雾试验（CASS试验）是国外新近发展起来的一种快速盐雾腐蚀试验，试验温度 为50℃，盐溶液中加入少量铜盐—氯化铜，强烈诱发腐蚀。它的腐蚀速度大约是NSS试验的8倍。 (4) 交变盐雾试验是一种综合盐雾试验，它实际上是中性盐雾试验加恒定湿热试验。它主要用于空腔 型的整机产品，通过潮态环境的渗透，使盐雾腐蚀不但在产品表面产生，也在产品内部产生。它是将产品在盐雾和湿热两种环境条件下交替转换，最后考核整机产品的电性能和机械性能有无变化。
表面处理用中性盐雾试验作业指导书 1.适用范围:本标准规定为各项金属底材于电镀后、有机或无机涂装后等各项表面处理用之盐水喷雾耐触性试验方法. 2.试验方法:本法是使用盐水喷雾试验机将氯化纳溶液,以雾状喷于被覆膜上之一种腐蚀试验方法.试验的主要条件如 表1所示. 表1主要的试验条件 项目配制时试验中备注 氯化钠溶液浓度（g/L）50 40~60 最好每天标定浓度一次 PH值 6.5 6.5-7.2 收集后测定试验中的PH值 压力桶压力（kgf/cm2）－2.00± 0.01 连续不得中断 喷嘴压力（kgf/cm2）－1.00± 0.01 连续不得中断 喷雾量（ml/80cm2/h）－ 1.0~2.0 应至少收集16小时,求其平均值压力桶温度（℃）－47±1 盐水桶温度（℃）－35±1 试验室温度（℃）－35±1 每天至少测试两次,其间隔至少7小时试验时间－－即由开始喷雾至终了的连续时间,表2. 表2连续雾化时间表 NO. 材质表面处理方式连续雾化时间 1 铜 镀镍12h 镀锡8h 先镀镍再镀锡24h 镀金24h 2 SPCC(冷轧钢板) 镀镍12h 镀铬16h 镀锡8h 镀白锌24h 镀蓝锌24h 镀彩锌24h 喷粉末涂料48h 喷油漆48h 3 铝合金本色阳极氧化48h 阳极发黑48h 4 螺丝类 镀锌12h 镀亮锌12h 镀亮镍8h 镀黑镍8h 5 SECC(镀锌钢板) 8h 6 不锈钢96h 3.试验液之配制:溶解氯化纳(化学纯、分析纯）于蒸馏水（或总溶解固体量小于200ppm以下的水中）,调配成浓度为 5±0.1%的试验液.此试验液在35℃喷雾后,其收集液PH值应为6.5~7.2.且喷雾前,此试验液不能含有浮态物.