1、Guide to SSPC-VIS 2June 1, 2000Editorial Revisions November 1, 20042-371. Scope 1.1 This standard provides a method to evaluate the degree of rusting on painted steel (or iron) surfaces. The refer-ence color photographs and corresponding black and white images, which depict the percentage of rusting
2、 given in the written specifi cation, form part of the standard. In the event of a dispute, the written defi nitions prevail. 1.2 This standard is particularly useful for evaluating rust on test panels or on localized areas of structures (see Section 7.1).2. Description 2.1 This standard quantifi es
3、 the degree of rusting on painted steel surfaces with a zero to ten scale based on the percentage of visible rust present on the surface. Visible rust includes rust blisters and undercutting of the coating (see Section 7.3). 2.2 The distribution of the rust is classifi ed as spot rust, general rust,
4、 or pinpoint rust. 2.3 Standard reference photographs depict the appearance of painted steel surfaces with the appropriate percentage of rusting for various distributions of the rust. The rusting depicted in the photographs is not accompanied by blistering, but the photographs show staining associat
5、ed with the rust. Black and white images highlight only those areas that are rusted. Both the color photographs and the black and white images enable the evaluator to assign an accurate rust grade. 3. Referenced Standards 3.1 SSPC STANDARDS AND JOINT STANDARDS:VIS 1 Guide and Reference Photographs f
6、or Steel Surfaces Prepared by Dry Abrasive Blast CleaningVIS 3 Guide and Reference Photographs for Steel Surfaces Prepared by Hand and Power Tool Cleaning VIS 4/NACE VIS 7 Guide and Reference Photographs for Steel Surfaces Prepared by Waterjetting 3.2 ASTM INTERNATIONAL STANDARD:D 610 Standard Metho
7、d of Evaluating Degree of Rusting on Painted Steel Surfaces3.3 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO) STANDARD:4628-3 Paints and varnishes Evaluation of degradation of coatings Designation of quantity and size of defects, and of intensity of uniform changes in appearance Part 3: Assess
8、ment of degree of rusting4. Rust Grade Scale 4.1 The painted steel surface to be evaluated for degree of rusting shall be assigned a rust grade based on the percentage of visible rust on the surface. The rust grade scale is defi ned in Table 1. The scale and description shown in Table 1 shall be use
9、d in conjunction with the photographic reference standards (see Notes 9.1, 9.2 and 9.3).5. Rust Distribution 5.1 SPOT RUSTING: Spot rusting occurs when the bulk of the rusting is concentrated in a few localized areas of the painted surface. The reference photographs depicting this type of rusting ar
10、e labeled 9-S through 1-S (see Note 9.4.)5.2 GENERAL RUSTING: General rusting occurs when various size rust spots are randomly distributed across the surface. The reference photographs depicting this type of rusting are labeled 9-G through 1-G (see Note 9.4). 5.3 PINPOINT RUSTING: Pinpoint rusting o
11、ccurs when the rust is distributed across the surface as very small individual specks of rust. The reference photographs depicting this type of rusting are labeled 9-P through 1-P (see Note 9.4). 5.4 OTHER RUSTING: An actual rusting surface may be a hybrid combination of the types of rust distributi
12、on depicted in the reference photographs. In this case, combinations of the photographs and rust grades may be needed to classify the surface. SSPC: The Society for Protective CoatingsGUIDE TO SSPC-VIS 2Standard Method ofEvaluating Degree of Rusting on Painted Steel Surfaces Guide to SSPC-VIS 2June
13、1, 2000Editorial Revisions November 1, 20042-386. Conditions Depicted6.1 The standard contains 27 color photographs of painted surfaces and the corresponding black and white rust images illustrating the maximum percentage of rusting allowed for each rust grade from rust grade 9 to rust grade 1 for t
14、hree different rust distributions. Each color photograph and black and white image are labeled with the corresponding numerical rust grade followed by a letter indicating the type of rust distribution. The percentage of visible rust is also shown with each reference photograph. No photographs are us
15、ed to depict rust grade 10 (less than 0.01 percent rust) or to depict rust grade 0 (over 50 percent rust). (See Note 9.5.)7. Procedures 7.1 SELECT AREA: Select the area which is to be evaluated for degree of rusting. This area may be as small as a test panel or as large as the hull of a ship. For co
16、mplex structures, each member may be evaluated as a whole, or different sections may be evaluated separately (e.g., top of fl ange, web of a beam, or edges). 7.2 DETERMINE RUST DISTRIBUTION: Determine the rust distribution (spot, general, or pinpoint) that most closely matches the selected area. Com
17、pare the selected area with the corresponding color photograph or black and white image. Determine the percentage of rust on the surface by visual comparison with the reference photographs, by electronic scanning techniques, or other methods agreed upon by the contracting parties. 7.3 DETERMINE RUST
18、 GRADE: The rust grade is deter-mined by the percentage of visible rust on the surface as defi ned in Table 1. If rust buildup is evident under the coating, as in a rust blister or as rust undercutting, then that rusted area shall be included in the determination of the rust grade. 7.3.1 A rust blis
19、ter is defi ned as a spot on a painted surface where the coating is intact but raised from the surface by the expansion of rust. The rust is not visible, but lies beneath the coating. A rust blister is not the same as a fl uid-fi lled blister, which is typically caused by osmotic pressure or solvent
20、 entrap-ment. The volume of rust (if present) in a fl uid-fi lled blister is a small percentage of the volume of the blister, whereas rust occupies most of the volume of a rust blister. A fl uid-fi lled blister may collapse, but a rust blister will not collapse (see Notes 9.6 and 9.7). Fluid-fi lled
21、 blisters should not be included in the determination of the rust grade. 7.3.2 If rust blisters are present, the rust grade shall be determined considering the rust blisters as visible rust. This rating must be recorded in such a manner that it is clear to the contracting parties that rust blisters
22、were present and that they were considered as visible rust when assigning a rust grade. 7.3.3 Rust undercutting at a damaged area, at a broken blister, or at a place where the painted surface meets a rusted area, shall be considered as visible rust in the determination of the rust grade. A dull putt
23、y knife may be used to remove loose coating, thereby exposing the rusted areas. 7.4 OTHER CONSIDERATIONS: Care must be exercised when determining the percentage of rust on the surface. 7.4.1 Some fi nishes are stained by rust. This staining shall not be considered as rust. 7.4.2 Accumulated dirt or
24、other material may make accurate determination of the degree of rusting diffi cult. This dirt shall not be considered as rust. 7.4.3 Certain types of dirt that contain iron or iron compounds may cause surface discoloration that should not be mistaken for corrosion. 7.4.5 In evaluating surfaces, cons
25、ideration shall be given to the color of the fi nish coating. A light surface that contrasts with the rust may appear to have a lower rust grade than a similarly rusted surface with a color that blends with the rust. 7.5 REPORTING: Report the area or item evaluated, the type or types of rust distrib
26、ution, the presence of rust blisters (if applicable), and the rust grade. 8. Disclaimer 8.1 While every precaution is taken to ensure that all information furnished in SSPC guides and standards is as TABLE 1SCALE AND DESCRIPTION OF RUST GRADESSpot General Pinpoint10Less than or equal to 0.01 percent
27、9Greater than 0.01 percentto 0.03 percent 9-S 9-G 9-P8Greater than 0.03 percentto 0.1 percent 8-S 8-G 8-P7Greater than 0.1 to 0.3 percent 7-S 7-G 7-P6Greater than 0.3 percent to 1 percent 6-S 6-G 6-P5Greater than 1 percent to 3 percent 5-S 5-G 5-P4Greater than 3 percent to 10 percent 4-S 4-G 4-P3Gre
28、ater than 10 percent to 16 percent 3-S 3-G 3-P2Greater than 16 percent to 33 percent 2-S 2-G 2-P1Greater than 33 percent to 50 percent 1-S 1-G 1-P0 Greater than 50 percentRust Grade Percent of Surface RustedPhotographic StandardNONENONEGuide to SSPC-VIS 2June 1, 2000Editorial Revisions November 1, 2
29、0042-39accurate, complete, and useful as possible, SSPC cannot assume responsibility nor incur any obligation resulting from the use of any materials or methods described herein, or of the guide or standard itself.8.2 This guide does not attempt to address problems concerning safety associated with
30、its use. The user of this guide, as well as the user of all products or practices described herein, is responsible for instituting appropriate health and safety practices and for ensuring compliance with all governmental regulations.9. Notes 9.1 The rust grade scale is designed for use in distin-gui
31、shing relatively large changes in the percentage of rust on the surface. For example, this standard is not intended to distinguish between 3.5 and 3.6% rust, even if electronic scan-ning equipment is used. For low rust levels, the amount of rust must triple before falling to the next rust grade. The
32、 standard photographs and the black and white images aid the inspector in distinguishing between adjacent rust grades.9.2 The numerical rust grade is a logarithmic function of the percent area of rust so that slight amounts of initial rusting have the greatest effect on lowering the rust grade. The
33、graph of rust grade versus log (percent rust) is a straight line from rust grade 10 to rust grade 4. The slope of the curve was changed between 10 percent of the area rusted to 100 percent rusted to permit inclusion of complete rusting on the 0 to 10 rust grade scale. The relationship between the ru
34、st grade, R, and the maximum percent of rusting, P, is approximated closely by the equations:R = 6 2 Log (P) for rusting from 0.01% to 10% (rust grades 10 to 4), andR = 8 4 Log (P) for rusting from 10% to 100% (rust grades 4 to 0). 9.3 Table 2 compares the rust grades defi ned by ISO 4628-3 with the
35、 European rust scale and with the rust grades defi ned by this standard. 9.4 Spot rusting has been associated with barrier coat-ings such as epoxy or urethane coatings. General rusting has been associated with oil, alkyd, and latex paints. Pinpoint rusting has been associated with untopcoated zinc-r
36、ich coat-ings, thin inadequately applied coatings, or as fl ash rusting on waterborne primers.9.5 In addition to this standard, SSPC has visual standards for blast cleaned steel (SSPC-VIS 1), for hand and power tool cleaned steel (SSPC-VIS 3), and for steel cleaned by waterjet-ting (SSPC-VIS 4/NACE
37、VIS 7). 9.6 The nature of a blister can usually be determined visu-ally, by touching it, or by breaking it. If the blister has collapsed, it was a fl uid fi lled blister. If liquid fl ows out and the blister then collapses, it was a fl uid fi lled blister. The hard build-up of rust beneath the paint
38、 can usually be felt by touching the blister, thereby identifying it as a rust blister. If these methods are inconclusive, cutting the blister with a knife or carefully scraping it off with a dull putty knife will make it easy to determine the nature of the blister.9.7 Fluid fi lled blisters should
39、not be considered in deter-mining the rust grade. A fl uid fi lled blister may form in a rela-tively short time and then remain intact for years, especially in immersion environments. A fl uid fi lled blister may form between coats while the steel substrate is still protected.Rust Grade versus Log (
40、percent rusting)012345678910RLog (percent rusting)-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 Log (P)Percent rusting0.01% 0.03% 0.1% 0.3% 1% 3% 10% 16 100% P33 50TABLE 2 APPROXIMATE CORRELATION AMONG SSPC/ASTM, ISO, AND EUROPEAN RUST GRADE SCALES* ISO 4628-3* “European scale of degree of rusting for ant
41、icorrosive paints” published by the Comit Europen des associations de fabricants de peintures et dncres dimprimerie in1964.Area Rusted,%Rust GradeArea Rusted,%Rust Grade0.01 10 0 Ri 0 Re 00.03 to 0.1 8 0.05 Ri 1 Re 10.3 to 1 6 0.5 Ri 2 Re 20.3 to 1 6 1 Ri 3 Re 33 to 10 4 8 RI 4 Re 533 to 50 1 40/50 Ri 5 Re 7ISO*European RustGrade*SSPC-VIS 2/ASTM D 610Guide to SSPC-VIS 2June 1, 2000Editorial Revisions November 1, 20042-40Rust Grade 8, 0.01% Rusted Rust Grade 5, 3% RustedGeneral DistributionPinpoint DistributionSample Black and White Images from SSPC-VIS 2Spot Distribution
