1、A967/A967M-13of free iron from the stainless steel surface would be an14.1.2 The sample representing the lot of passivated partsaqueous solution of sodium dichromate.shall be alternately immersed in a non-rusting tank of distilled10.2 When specified,within one hour after the final waterwater for 1 h
2、 and allowed to dry in air for I h.This cycle shallrinse as required in 6.2,7.2,or 8.3,all ferritic and martensiticbe repeated a minimum of twelve times.steel parts shall be immersed in an aqueous solution containing14.1.3 The tested sample shall not exhibit rust or staining4 to 6 weight percent of
3、sodium dichromate at a temperature inattributable to the presence of free iron particles embedded inthe range from 60 to 70C 140 to 160Ffor a minimum of 30the surface.min,followed by a rinse in accordance with 6.2,7.2,or 8.3.14.2 Practice B-High Humidity TestThe parts shall then be thoroughly dried.
4、14.2.1 This test is used for the detection of free iron or any10.3 The purchaser may specify other post-cleaning treat-other anodic surface contaminants on stainless steel.ments.14.2.2 The test shall be performed using a humidity cabinetcapable of maintaining the specified test conditions.11.Finish1
5、4.2.3 The sample representing the lot of passivated parts11.1 The passivated parts shall exhibit a chemically cleanshall be cleaned by immersion in acetone or methyl alcohol orsurface and shall,on visual inspection,show no etching,by swabbing with a clean gauze saturated with acetone orpitting,or fr
6、osting resulting from the passivation procedures.methyl alcohol,and dried in an inert atmosphere or desiccatedcontainer.The cleaned and dried part shall be subjected to 9712.Testing Agency3%humidity at 35 to 40C 95 to 105Ffor a minimum of24h.12.1 When required,the purchaser shall be permitted toperf
7、orm such inspections as necessary to determine that the14.2.4 The tested sample shall not exhibit rust or stainingtesting agency is capable of performing the specified test.attributable to the presence of free iron particles imbedded inthe surface13.Lot,Frequency of Testing,and Selection of Test14.3
8、 Practice C-Salt Spray Test13.1 Definition of Lot-A lot shall consist of one of the14.3.1 This test is used for the detection of free iron or anyfollowing,at the option of the processor:other anodic surface contaminants on stainless steel.13.1.1 The passivated parts of similar alloy and manufac-14.3
9、.2 The sample representing the lot of passivated partsturing methods that are pretreated and passivated in a singleshall be tested by the salt spray test conducted in accordanceday or within a time frame that will ensure consistent passiva-with Practice B117 for a minimum of 2 h using a 5 salttion r
10、esults;solution.13.1.2 The passivated parts of the same product of one size14.3.3 The tested sample shall not exhibit rust or stainingfrom one heat in one shipment;orattributable to the presence of free iron particles imbedded in13.1.3 When few parts are involved,the passivated partsthe surface.from
11、 an entire production run14.4 Practice D-Copper Sulfate Test13.2 Unless a greater frequency of testing is specified on the14.4.1 This test is recommended for the detection of freepurchase order,one test per lot shall be sufficient.iron on the surface of austenitic stainless steels in the 200 and13.3
12、 One of the tests listed in Section 14,or more when300 series,precipitation hardened stainless steels,and ferritic400 series stainless steels having a minimum of 16%chro-specified on the purchase order.shall be performed on each lotmium.This test is not recommended for martensitic 400 seriesof stain
13、less steel parts to verify the effectiveness of thepassivation treatment.It is important to note that not all of thestainless steels or for ferritic 400 series stainless steels with lessfollowing tests are suitable for all grades of stainless steel.(Seethan 16%chromium because these steels will give
14、 a positiveNote 5.)indication irrespective of the presence or absence of anodic13.3.1 Practice A-Water Immersion Test(see 14.1).surface contaminants.This test shall not be applied to parts to13.3.2 Practice B-High Humidity Test(see 14.2),be used in food processing.13.3.3 Practice C-Salt Spray Test(s
15、ee 14.3),14.4.2 The test solution is prepared by dissolving 4 g of13.3.4 Practice D-Copper Sulfate Test(see 14.4),copper sulfate pentahydrate(CuSO5H2O)in 250 mL of13.3.5 Practice E-Potassium Ferricyanide-Nitric Aciddistilled water to which I mL of 96 to 100%sulfuric acidTest(see 14.5),and(H2SO)has b
16、een added.14.4.3 The test solution is swabbed on the surface of the13.3.6 Practice F-Damp Cloth Test(see 14.6).sample representing the lot of passivated parts,applyingNorE 5-Some of the tests may produce positive indications notadditional solution as needed to keep the surface wet for aassociated wi
17、th the presence of free iron on the stainless steel surface.Anperiod of at least 6 min.At the end of this period,the surfaceexample would be application of Practice C on some lesser-alloyedmartensitic or ferritic stainless steels.shall be carefully rinsed and dried with care taken not to disturbcopp
18、er deposits if present.14.Verification Tests14.4.4 The tested sample shall not exhibit copper deposits14.1 Practice A-Water Immersion Test14.5 Practice E-Potassium Ferricyanide-Nitric Acid Test14.1.1 This test is used for the detection of free iron or any14.5.1 This test is recommended when detection of veryother anodic surface contaminants on stainless steel.small amounts of free iron is required.It is recommended forCopyright by ASTM Intl(all rights reserved):