GB/T 6807-2001Specifications for phosphating treatment of iron and steel parts before painting (English PDF)

Foreword

This standard is the revision of GB/T 6807-1986. AND the main technical changes are as follows.

- In accordance with the requirements of GB/T 1.1, ADD the foreword, scope, and normative references;

- DELETE the "2.8.2, 3.3.2" from the original standard, as well as the corresponding "Appendix D Drop method (Informative)" The Appendix A of this standard is a normative appendix, AND the Appendix B is an informative appendix.

This standard shall, from the date of implementation, replace GB/T 6807-1986.

1 Scope

This standard specifies the classification, technical requirements, inspection methods and acceptance rules of the phosphating film of iron and steel parts before painting.

This standard is applicable to the phosphating treatment iron and steel parts before painting. The phosphating film as formed after treatment is used as the coating base to enhance the adhesion and corrosion resistance of the coating and the steel matrix, AND to improve the coating quality of the iron and steel parts.

2 Normative references

The provisions in following documents become the provisions of this Standard through reference in this Standard. The versions indicated at the time of publication of this standard are valid. All standards are subjected to revision, AND parties who reach an agreement based on this Standard are encouraged to study if the latest versions of these documents are applicable.

GB/T 1765-1979 Method of producing of paint films for testing heat and humidity resistance, salt-fog resistance and accepted weathering

GB/T 1771-1991 Paints and varnishes - Determination of resistance to neutral salt spray

GB/T 2828-1987 Sampling procedures for inspection by attributes - Part 1:

Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection

GB/T 9286-1998 Paints and varnishes - Cross cut test for films (eqv ISO 2409:1992)

GB/T 9792-1988 Coatings on metallic materials - Determination of coating mass per unit area - Gravimetric methods

4 Technical requirements

5 Test method

6 Acceptance rules

6.1.2 USE the material same as the workpiece to prepare a 70 mm x 150 mm size sample and MAKE it subjected to treatment simultaneously with the workpiece.

6.2 The appearance inspection is as follows.

6.2.1 Large workpieces and important workpieces shall be 100% inspected and accepted one by one.

6.2.2 General workpieces (including small workpieces) may be sampled, inspected and accepted in accordance with GB/T 2828, AND the inspection rules are as shown in Appendix A (normative).

6.3 In case of determination of the phosphating film weight, if the average value of the 3 parallel samples under the test is disqualified, it shall re-take 3 samples for re-inspection, and if the average value is still disqualified, this batch of products shall be deemed as disqualified.

6.4 In case of corrosion resistance test of the phosphating film, it shall take 3 samples from each batch of workpieces for inspection; if one workpiece is disqualified, it shall double the samples for re-inspection. If there is one disqualified in the re-inspection results, it shall follow the requirements of 6.6 to conduct inspection AND the inspection results shall prevail.

6.5 The spot inspection of the phosphating film weight and coating film corrosion resistance shall be conducted under one of the following conditions.

6.5.2 Periodic inspection specified by the enterprise;

6.5.3 Change of equipment, process or bath formulation;

6.6 In case of corrosion resistance test of the coating film, it shall take 3 samples from each batch of workpieces for inspection; if one workpiece is disqualified, it shall double the samples for re-inspection. If there is one disqualified in the re-inspection results, this batch of products shall be deemed as disqualified. […]