This part of GB/T 8923 specifies a series of treatment grades for steel surfaces after partial removal of existing coatings. This part of GB/T 8923 applies to steel surfaces that have been treated before coating by methods such as blast cleaning, manual and power tool cleaning, and mechanical grinding. This part is equivalent to ISO 8501-2:1994 "Surface preparation of steel before coating - Visual assessment of surface cleanliness - Part 2: Treatment grades for coated steel surfaces after partial removal of existing coatings" (English version). This part is equivalent to the translation of ISO 8501-2:1994. GB/T 8923.2-2008 Surface preparation of steel substrates before application of paint Visual assessment of surface cleanliness Part 2: Grades of treatment of previously coated steel substrates after partial removal of existing coatings GB/T8923.2-2008 Standard download decompression password: www.bzxz.net
This part of GB/T 8923 specifies a series of grades of treatment of steel substrates after partial removal of existing coatings. This part of GB/T 8923 is applicable to steel substrates that have been treated before application of paint by methods such as blast cleaning, manual and power tool cleaning, and mechanical grinding. This part is equivalent to ISO 8501-2:1994 "Surface preparation of steel substrates before application of paint Visual assessment of surface cleanliness Part 2: Grades of treatment of previously coated steel substrates after partial removal of existing coatings" (English version). This part is equivalent to the translation of ISO 8501-2:1994.
class="f14" style="padding-top:10px; padding-left:12px; padding-bottom:10px;"> GB/T8923 "Surface preparation of steel before coating - Visual assessment of surface cleanliness" is divided into the following parts:
--- Part 1: Rust grade and treatment grade of uncoated steel surfaces and steel surfaces after complete removal of the original coating;
--- Part 2: Treatment grade of coated steel surfaces after partial removal of the original coating;
--- Part 3: Treatment grade of surface defects in welds, cut edges and other areas;
--- Part 4: Initial surface state, treatment grade and rust removal grade related to high-pressure water jet treatment.
This part is Part 2 of GB/T8923.
This part is equivalent to ISO8501-2:1994 "Surface preparation of steel substrates before application of paint - Visual assessment of surface cleanliness - Part 2
: Grades of preparation of coated steel substrates after partial removal of existing coatings" (English version).
This part is equivalent to the translation of ISO8501-2:1994.
For ease of use, this part has been edited as follows:
--- The term "this international standard" has been changed to "this part";
--- The comma used in the sub-statement has been replaced by a semicolon;
--- The foreword and introduction of the international standard have been deleted;
--- As the introduction of the international standard has been deleted, Note 1 has been deleted accordingly, so the note numbers in the text have been modified;
--- For clarity, secondary item numbers have been added to 4.2, 4.3 and 4.4, and the item title overviews of 4.2.1, 4.3.1 and 4.4.1 have been added accordingly; in Chapter 5 and 5.1, 5.2 and 5.3, the hanging paragraphs at the beginning have been added with item numbers and item titles, and the subsequent item numbers have been modified accordingly;
--- Bibliography has been added as informative Appendix A.
This part was proposed by China State Shipbuilding Corporation.
This part is under the jurisdiction of the Sub-Technical Committee on Metal Surface Treatment and Painting Technology before Painting of the National Technical Committee on Standardization of Paints and Pigments.
The drafting units of this part: China Shipbuilding Industry Comprehensive Technology and Economic Research Institute, China Shipbuilding Industry 11th Research Institute, Shandong Kaitai Metal Abrasive Co., Ltd. The
main drafters of this part: Song Yanyuan, Liu Bingyang, Fu Jianhua, Liu Ruwei, Wang Ruiguo, Liu Chunbo.
The clauses in the following documents become the clauses of this part through reference in this part of GB/T 8923. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this part. However, the parties to the agreement based on this part are encouraged to study whether the latest versions of these documents can be used. For any undated referenced document, the latest version shall apply to this part.
GB/T5210-2006 Paints and varnishes - Pull-off adhesion test (ISO4624:20021), IDT)
ISO2409:19922) Paints and varnishes - Cross-cut test
ISO4627:1981 Paints and varnishes - Test method for assessing the suitability of coatings to surfaces to be coated
ISO4628-1:19823) Paints and varnishes - Assessment of film degradation - Assessment of the degree, number and size of common types of defects - Part 1: General principles and grade table
ISO4628-2:1982 Paints and varnishes - Assessment of film degradation - Assessment of the degree, number and size of common types of defects - Part 2: Assessment of blistering grade
ISO4628-3:1982 Paints and varnishes - Assessment of film degradation - Assessment of the extent, number and size of common types of defects - Part 3: Assessment of the degree of rusting
ISO 4628-4:1982 Paints and varnishes - Assessment of film degradation - Assessment of the extent, number and size of common types of defects - Part 4: Assessment of the degree of cracking
ISO 4628-5:1982 Paints and varnishes - Assessment of film degradation - Assessment of the extent, number and size of common types of defects - Part 5: Assessment of the degree of flaking

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National Standard of the People's Republic of China
GB/T8923.2—2008/ISO8501-2:1994 Surface preparation of steel substrates before application of paints and related products-Visual assessment of surface cleanliness-Part 2: Preparation grades of previously coated steel substrates after localized removal of previous coatings(ISO8501-2:1994.IDTE
2008-04-01Release
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of ChinaStandardization Administration of the People's Republic of China
2008-09-01Implementation
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GB/T8923.2—2008/SO8501-2:1994GB/8923 Surface preparation of vehicle materials before coating Visual assessment of surface cleanliness is divided into the following parts: Part 1 Rust grades and treatment grades of uncoated steel surfaces and steel surfaces after complete removal of existing coatings: Part 2 Rust grades and treatment grades of coated steel surfaces after partial removal of existing coatings Treatment levels: Part 3: Treatment levels for surface defects of welds, cut edges and other areas: Part 4 Initial surface condition, treatment levels and rust removal levels related to high-pressure water jetting treatment This part is Part 2 of GB/T 8923
This part is equivalent to 1S08501-2:1994 & Surface preparation of steel before coating Visual assessment of surface cleanliness Part 2 Treatment levels of coated steel surfaces after local removal of existing coatings (English version) This part is equivalent to 1S08501-2:1994 For the convenience of use, this part has made the following abbreviation changes: "This international standard" is changed to "this part": The semicolon "\" is used instead of the "\" as a sub-description: The foreword and introduction of the international standard are deleted:
Due to the deletion of the introduction of the international standard. The "Note" in it was removed, so the note number in the text was modified: for clarity, add secondary item numbers in 4.2.4.3 and 4.4. And add the title "Overview" of 4.2.1.4.3.1.4.4.1 accordingly. In Chapter 5 and 5.1.5, 25.3, add item numbers and item titles to the suspended paragraphs at the beginning, and the subsequent item numbers are modified accordingly:
Added references as informative appendix A This part is proposed by China State Shipbuilding Corporation. This part was drafted by the National Technical Committee for Standardization of Coatings and Colors, Metal Surface Treatment before Painting and Coating Technology Sub-Committee. Drafting units of this part: China Shipbuilding Industry Comprehensive Technology and Economic Research Institute, China Shipbuilding Industry Tenth Research Institute Shandong Kaifeng Metal Tang Material Co., Ltd.
The main drafters of this part: Wei Yanyuan, Liu Bingyang, Bo Jianhua, Liu Ruwei, Wang Ruiguo, Liu Chunbo. Standard download station
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1 Scope
GB/T8923.22008/1SO8501-2:1994 Surface preparation of steel before coating
Visual assessment of surface cleanliness
Part 2: Treatment grades of coated steel surfaces after partial removal of the original coating
This part of GB/T8923 specifies a series of surface treatment grades after partial removal of the original coating, various treatments The grades are defined by the typical sample photos given in the document (see Chapter 4) and ISO85011. In addition, photo samples showing the treatment grades PSa2 and PMa are given. This part of GB/T 8923 applies to steel surfaces that have been treated before coating by methods such as blast cleaning, manual and dynamic tool cleaning, and mechanical grinding. This part of GB/T 8923 expresses the surface cleanliness of steel by its visual appearance. In most cases, this meets the requirements, but for coatings that are likely to be placed in harsh environments, such as water environments and cold rat environments, physical and chemical methods should be considered to detect soluble substances on surfaces that appear to be clean to the naked eye. Salt and other unobservable contaminants. Specific detection methods are specified in the various parts of IS0502. Surface roughness characteristics should also refer to the provisions of IS08503. 2 Normative referenced documents
The clauses in the following documents become clauses of this part through reference in this part of GB/T8923. All subsequent amendments (excluding errors) or revisions of dated referenced documents are not applicable to this part. However, the parties who have reached an agreement based on this part are encouraged to study whether the latest versions of these documents can be used. For any undated referenced documents, the latest versions apply to this part.
GB/T5210-2006
Color and varnish Open adhesion test (IS01624: 2002″, DT31S0240919923 Paints and varnishes cross-cut test ISO4627: 1981
Paints and varnishes - Test method for evaluation of suitability for micro-surfaces IS04628-1: 19823
Paints and varnishes
Part 1: General and grade tables
1S04628-2: 1982 Paints and varnishes
Part 2: Evaluation of corrosion grades
IS4628-3: 1982 Paints and varnishes
Part 3: Evaluation of rust grades
1S4628-4: 1982 Paints and varnishes| |tt||Part 4: Assessment of the degree of finish
Assessment of film aging
Assessment of film aging
Assessment of film aging
Assessment of degree, quantity and size of general cosmetic defects Assessment of degree, quantity and size of general type defects Assessment of degree, quantity and size of general type defects Assessment of clear film aging
Assessment of degree, quantity and size of general type defects ISO4628-5:1982 Assessment of paint and varnish film aging Assessment of degree, quantity and size of general type defects Part 5: Assessment of peeling grade
1 In 1S08501-2:1994, this standard number is 15046 24:1987 1504624:2002 1S04624:198721GT02861998 is equivalent to 1501240919923) G1/T1766-1995 is not equivalent to 1S (24628-1-4628-5:1980 Standard Download Station
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GB/T8923.2-2008/1SO8501-2:1994IS04628-6:1990 Paints and varnishes - Assessment of ageing of films - Assessment of the extent, number and size of defects - Part 6: Adhesive tape assessment method for chalking degree 1S 08501-1.1988 Surface preparation of steel materials before coating Visual assessment of surface cleanliness Part 1: Uncoated steel surfaces Rust grades and treatment grades of steel surfaces after complete removal of existing coatings 3 Condition of specially cleaned coated surfaces
The degree of defects in the removed coating should be assessed in accordance with the provisions of [S04628 Parts 1 to 6]. If possible, supplementary information related to the original coating should be given, including type of coating system, number of applications, manufacturer's name, corrosive contaminants, adhesion and film thickness. 4 Treatment grades
4.1 General
This part specifies a number of treatment grades representing different surface preparation methods and degrees of cleanliness. The treatment level is defined by words describing the appearance of the surface after treatment (see 4.2.4.3 and 4.4). Each treatment level is represented by the letters "Sa", "St" or "Ma" representing the type of treatment method. The letter "Sa", "St" or "Ma" placed in front of Sa, St or Ma indicates the removal of the original coating. The number "Ma" placed after the letter "Sa" indicates the removal of the original coating. It should be recognized that the various treatment methods do not give comparable results. The treatment level should be consistent with the type of coating system used for re-coating.
4.2 and 4.The photographs in 1S08501-1 referred to in 3 are typical samples of the treatment grades. NOTE 14.2. The term "foreign matter" as used in 4.3 and 4.4 includes volatile salts and residual flux. Impurities that cannot be completely removed from the surface by dry blasting, hand or power tool cleaning and mechanical grinding may be blasted. NOTE 2: If scale, rust or coating can be scraped off with a blunt oil tool, the unblasted part is not removed. The attached typical photographs show typical samples of copper materials before and after local cleaning. 4.2 Local blasting of coated surfaces PSa 4.2.1 General
For surface treatments for local blasting, the letters "PSa\" are used to indicate that all thick rust layers should be removed before blasting. Visible oil, grease and dirt should be removed. The surface should be cleaned after blasting. Note: For surface blasting, all thick rust layers should be removed. Visible oil, grease and dirt should be removed. The surface should be cleaned after blasting. Description of treatment methods including treatment procedures before and after blast cleaning, see S4 4.2.2 Thorough local blast cleaning PSa2
Firmly adhered coatings should be intact. The rest of the surface, when viewed without magnification, should be free of visible oil, grease and dirt, free of loose coating + almost free of scale, rust and foreign matter, and any remaining dirt should be firmly adhered (see Note 2 in 41): For comparison, see photos CSa2 and DSa2 given in ISO8501-1. The choice of which depends on the extent of the pitting. 4.2.3 Very thorough local blast cleaning PS Sa 22 The coating to which the solid is attached should be intact. The rest of the surface, when viewed without magnification, should be free of visible grease and matter, loose coating, scale, rust and foreign matter. Any remaining traces of contamination should only appear as slight stains in the form of dots or stripes. For comparison, see the photographs given in ISO 8501-1. Sa 2 D Sa 2 The choice of which depends on the extent of the pitting. This standard gives typical photographic samples showing the surface grade PSa2. 4.2.4 Local blast cleaning to visually clean steel PSa3 The firmly attached layer should be intact and the rest of the surface, when observed without magnification, should be free of visible oil, grease and calcium 43GB/T8928-1988 is equivalent to ISO8501-1:19882bzxZ.net
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CB/T 8923.2--2008/ISO:8501-2.1994 The surface shall be free from loose coatings, scale, rust and foreign matter. It shall have a uniform metallic colour. For comparison, see photos CSa3 and DSa3 given in ISO 8501-1. The choice depends on the extent of corrosion pitting. NOTE This standard does not include treatment grade Ssl+ because surfaces of this grade are not suitable for coating. 4.3 Local hand and power tool cleaning of coated surfaces PSt 4.3.1 Overview
Surface preparation for local hand and power tool cleaning, such as scraping, brushing, grinding, etc., is indicated by the letters "PS". Before cleaning, any rust layer and visible oil, grease and dirt should be removed. After hand and power tool cleaning Remove the surface aerosol and debris: For the description of the surface preparation of hand and power tool cleaning, including the treatment procedures before and after hand and power tool cleaning, see ISO 8504-4.3.2 Thorough local hand and power tool cleaning PSt2 The coating should be intact when firmly attached. The rest of the surface should be free of visible oil, grease and dirt, loosely attached scale, rust coating and foreign matter when viewed without magnification (see Note 2 in 4.1). For comparison, see the photographs given in ISO 8501-1 PSt2 and PSt2. The choice depends on the extent of corrosion pitting. 4.3.3 Very thorough local hand and power tool cleaning PSt3 Same as PSt2. The surface to be cleaned should be prepared more thoroughly and the metal base should have a metallic luster. For comparison purposes, see the photographs CSt3 and DSt3 given in ISO 801-1. The choice of which depends on the extent of the etch back pits. NOTE: Treatment grades PS and PS3 have nothing to do with the use of specific hand and power tools and are determined entirely by the treatment grade definitions in this specification with the aid of typical photographs. NOTE 2 Treatment grade PS is not included in this standard because surfaces of this grade are not suitable for coating. 4.4 Local mechanical grinding of coated surfaces PMa 4.4.1 General The letters "PM" are used to designate surfaces that have been cleaned by local mechanical grinding and include a complete mechanical grinding process. Mechanical grinding (e.g. with a sandpaper abrasive disc or a special rotating wire brush, which can be used with a needle spray gun). Any thick rust layer and visible oil, grease and dirt should be removed before mechanical grinding. After mechanical grinding, the surface should be free of loose dust and debris. 4.4.2 Local mechanical grinding PMa
The firmly attached coating should be intact. The rest of the surface, when viewed without magnification, should be free of visible grease and dirt, loose coating, scale, rust and foreign matter (see Note 2 in 4.1). Any residual traces of contamination should appear only as slight stains in the form of dots or strips. For comparison, see the typical photo samples given in this section showing the treatment level PMa. NOTE The main treatment level PM has nothing to do with the use of the specific tools to be determined and is entirely determined by the treatment level definition illustrated with the help of the typical photo samples. 4.5 Treatment of remaining coatings
Before re-coating, the remaining part of the original coating, including any firmly attached primer and matching base coat after surface treatment, should be free of loose matter and contamination. If necessary, it should be roughened to ensure good adhesion. The adhesion of the remaining coating can be determined by a cross-cut test as defined in 1S02409, or according to GB/ T52102006 stipulates that the adhesion pull-off test should be carried out with a portable adhesion tester, or other appropriate inspection methods should be used for determination. The intact coating at the junction of the grinding or blast cleaning area should be repaired into an inclined shape to form a complete and firm adhesion edge. The new coating should match the original Xu layer. 1SO4627 gives suggestions for evaluating compatibility. 5 Photos
5.1 General
The typical photo samples given in this section are the typical area appearance before and after local treatment before re-coating (magnification 6 times). 5 Except for mechanical grinding + see 4. Special
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GB/T8923.2—2008/IS08501-2:1994 For ease of manufacturing, the plastic paper printed with photos is not numbered. For ease of use, the photos are arranged in the order shown in Figure 1. On each page, the upper photo shows the surface condition before surface treatment, and the lower photo shows the surface condition after surface treatment. For detailed description of the surface treatment area, see 5.2~5,45.2 Typical example of very thorough local blast cleaning (PSa2) 5 .2.1 Overview
The first and second sample photos and 5.2.2 and 5.23 are two typical examples encountered in practice and their explanations. 5.2.2 Iron oxide red shop primer (first sample photo) The photo shows a surface coated with iron oxide red shop primer before and after blast cleaning. On the left side of the photo, a rusted weld joint is visible. At the same time, a rusted weld is also visible in the upper right. 5.2.3 Anti-corrosion system (second sample photo) The photo shows a surface where the anti-corrosion system (red lead/micaceous iron oxide) has been exposed for a long time. Before and after blast cleaning In the upper part of the photo, a widely distributed rusted area and an intact coating area can be seen. The intact coating area should be cleaned and roughened before the surface is completely re-coated. 5.3 Very thorough local blast cleaning (extreme example of PSa2> 5.3.1 Overview
The third and fourth sample photos and 5.3.2 and 5.3.3 are extreme examples of possible application of treatment level PSa2 and their explanation.
5.3.2 An intact coating (third sample photo) The photo shows a layer that is generally intact and has no pitting corrosion. Example of local blast cleaning, where only local repairs are required. Damaged coatings can also be treated by rubbing, scraping or brushing.
5.3.3 An unsuitable coating (the fourth sample photo) The photo shows a coating with only slight visible rust spots, but it must be completely re-coated. It should also be considered to completely remove the coating to surface preparation level Sa2#
5.4 Typical example of local mechanical grinding (PMa) 5.4.1 Overview
The fifth, sixth and seventh sample photos and 5.4.2 and 5.43 are three typical examples encountered in practice and their explanations. 5.4.2 Repair work
5.4.2.1 The upper surface of a hatch cover (the fifth sample photo) The photo shows a coating with two coats of red lead primer (fine red and brown) and two coats of gray synthetic resin topcoat, and an anti-corrosion system of about 15 was used. Since the surface has been cleaned with steam blasting.Weathering of the polyester coating system's traces is clearly visible in the photo above. The photo shows the surface before and after re-treatment (the rusted areas were mechanically polished with a sand disc and then rusted with a brush). 5.4.2.2 The upper surface of a steel beam (the sixth sample photo). The photo shows a road with two coats of primer (orange-red and brown), and two coats of colored synthetic resin topcoat. The anti-corrosion body of unknown age has local mechanical damage on the surface.
The photo shows the surface before and after re-treatment (the rusted areas were mechanically polished with a sand disc and then rusted with a brush). 5.4.3 New factory, power plant pipelines (seventh sample photo). Before installation, all external surfaces of the pipelines are spray cleaned to surface treatment grade Sa25, except for welds. Then two coats of epoxy/zinc chromate (reddish-brown) primer were applied. Then an epoxy (red/orange) intermediate coat was applied. The photo shows a pipe surface before and after re-treatment (the rusted areas and welds were mechanically polished: then the rust was removed and all residual impurities were removed using a saw.
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See 5.4.2.1
See 5.4.2.2
GB/T8923.22008/ISO8501-2:1994See 5.2.3
PSn256
Figure 1 Typical sample Layout and order of photos
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CB/T8923.2—2008/ISO8501-21994 See 5, 2.2
pSaays
Figure 1 (continued)
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Figure 1 (continued)
GB/T8923.2—2008/ISO8501-21994 Standards download station
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GB/T 8923.2—2008/1SO8501-2:1994 Now 5.3.2
Figure (continued)
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Figure 1 (continued)
GB/T8923.2—2008/ISO8501-2:1994Standard Download Station
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GB/T8923.2-2008/ISO8501-2.199410
See 5.4.2.1
Figure 1 (continued)
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