GB/T 25150-2010Quality test method of passive film on austenitic stainless steel of chemical cleaning for industrial equipment - Blue dot method (English PDF)

3.1 Passivation film passivefilm

Oxide passivation film is a protective film by chemical methods in austenitic stainless steel surface.

3.2 Blue Point liquid

Blue Point was dedicated to testing of austenitic stainless steel surface passivation film quality test solution, the solution itself is brown, the passivation film is destroyed after

The formation of blue spots.

3.3 Cleaning system

Cleaning system is also accept cleaning device or system by a plurality of devices, components and piping component.

4. Summary

Austenitic stainless steel surface passivation after dropping the liquid blue dot, blue dot fluid can damage the passive film, the following reaction. 2H Fe = Fe2

H2 ->; 3Fe2 2 [Fe (CN) 6] 3- = Fe3 [Fe (CN) 6] 2 ->. Blue dot appears with a stopwatch recording liquid within the coverage area and the number of blue dots

Time to assess the quality of the passivation film.

5.1

Test methods used in the reagents and water, did not indicate when the other requirements, refer to analytically pure reagents and GB/T 6682 provisions of the three steam

Distilled water.

Solution preparation and products 5.2 Test required, in the absence of other provisions indicated, was prepared according to the provisions of GB/T 603's.

5.3

Reagents and materials required for the test are as follows.

--- 98% sulfuric acid;

--- 36% hydrochloric acid;

GB/T 29465-2023 | GB/T 7996-2020 | HG/T 20537.3-1992 | GB/T 25147-2010 | GB/T 25146-2010 | GB/T 25145-2010 | […]