GB/T 8923.3-2009Preparation of steel substrates before application of paints and related products -- Visual assessment of surface cleanliness -- Part 3: Preparation grades of welds, edges and other areas with surface imperfections (English PDF)

Foreword

GB/T 8923 "steel substrates before application of paints Visual assessment of surface cleanliness" is divided into the following sections.

--- Part 1. uncoated steel surfaces and fully remove the original steel surface coating after Rust grades and preparation grades;

--- Part 2. coated steel surface has a partial removal of previous coatings after processing level;

--- Part 3. surface defects of welds, edges and other areas of the processing level;

--- Part 4. with high-pressure water jetting treatment-related initial surface condition, treatment and rust grade level.

This section GB/T 8923 Part 3.

This section identical with ISO 8501-3:2006 "before application of paints and steel surface cleanliness - Part 3 - Visual assessment Score. welds, edges and other areas of surface defects processing level "(in English).

This section is equivalent translation ISO 8501-3:2006.

For ease of use, this section made the following editorial changes.

--- "This International Standard" be replaced by "this section";

--- With a comma "," instead of a comma as described, "";

--- Remove the foreword and introduction of international standards.

This part is proposed by the China State Shipbuilding Corporation.

This part of the National Standardization Technical Committee before painting and metal surface treatment and painting processes Technical Committee paint pigment (SAC/TC5/SC6) centralized.

This section drafted by. China Shipbuilding Technology and Economy Research Institute, Jiangsu Rongsheng Heavy Industries Co., Ltd., China Shipbuilding Industry Group Eleventh Company Institute.

1 Scope

GB/T 8923 provisions of this part of the surface of the steel welds, edges and other areas of surface defects processing level. These defects may exist before and after the blast cleaning and visible.

Provisions of this Part apply to the processing level should be carried out before application of paints and steel surface with a surface treatment of defects, including welding surface.

2 Normative references

The following documents contain provisions which, through GB/T reference in this 8923 constitute provisions of this part. For dated reference documents Member, all subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to reach under this section Parties to research agreement to use the latest versions of these documents. For undated reference documents, the latest versions apply to this section.

ISO 12944-2 Paints and varnishes - Corrosion protection of steel structures coating systems - Part 2. Classification of environments ISO 12944-3 Paints and varnishes - Corrosion protection of steel structures coating systems - Part 3. Design content

3 Types of defects

This section provides defect classification as follows.

--- Welds;

---edge;

--- General surface.

And provisions of various defect types shown in Table 1.

4 Processing Level

Steel surface treatment before application of paints with a visible level is divided into three kinds of defects.

--- P1 mild treatment. no treatment before application of paints or only minimal processing;

--- P2 thorough treatment. Most of the defect has been cleared;

--- P3 very thorough treatment. surface without significant visible flaws. This major flaw more appropriate approach by all relevant Parties agreed on the basis of a specific construction process.

Processing level requirements in Table 1.

Note 1. The process to achieve these levels of treatment on the integrity of the steel surface or non-destructive weld area is very important. For example. Excessive grinding may it leads to the formation of heat-affected zone of steel surface and polished rely defect removal may leave sharp edges at the edge of the sanding area.

Note 2. Different structural defects may require different processing levels. For example. When the P2 level may be required to deal with all the other defects, undercut (Table 1 in 1.4) may be required to deal with the P3 level, especially when there is the appearance of a finish requirements, even if no resistance to corrosion requirements (see ISO 12944-2), also it may require treatment to P3 level.

Note 3. The well-known NACE Standard RP0178 gives a typical weld defects and their treatment level templates, the country needed to NACE International organizations purchase, PO Box is 218340 (POBox218340), address Houston, Texas, USA (Houston, Texas77218-8340, USA).

GB/T 8923.3-2009/ISO 8501-3:2006