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Jiangsu Gabriel Alloy Technology Co.,Ltd

Address:North Ring Road 168, Xishan District, Wuxi City, Jiangsu Province, China



321 Stainless Steel Pipe Inspection Method

Residue inspection and repair: with phenolphthalein indicator bar to check the 321 stainless steel pipe surface of the dilution of the residual liquid, PH neutral to meet the standard.

Blue dot try: Blue dot try the basic principle of the method, if the appearance of passivation film is incomplete or iron pollution. There will be free iron ions exist, potassium ferric chloride solution encountered iron ions that reflect the natural generation of blue precipitation.

100mL experimental cup 10g potassium ferricyanide dissolved in 50mI distilled water, dissolved after 30mI concentrated nitrite water, and then moved into the 1000mI volume of the top of the bottle of distilled water diluted to the mark, that is, blue point inspection repair solution, storage period of one week.

321 stainless steel pipe pickling passivation quality inspection repair can refer to the ship "stainless steel pickling passivation paste" CB / T3595-94, the international standard "stainless steel electrolytic lighting and polishing and pickling passivation formed by the appearance Passivation film inspection and repair "ISO15730 and so on, generally can be divided into: appearance inspection repair, chemical attempt, chemical attempt and the main artificial seawater film eruption attempt, copper sulfate titration attempt, high iron potassium cyanide titration try (blue point try ), Etc., the general inspection and repair the following three forms of implementation:

Appearance inspection repair: 321 stainless steel pipe pickled passivation appearance should be uniform silver color, bright and clean, can not have significant denervation remnants, weld and heat affected area can not have oxygen gas color, can not have the color of unfair scars.

Chemical test will damage the stainless steel passivation film, the general can be used with the test plate and 321 stainless steel pipe at the same time the implementation of pickling passivation, and then in the test plate long implementation of the above said try. Try: Check the blue dot to repair the liquid droplets on the indicator strip attached to the appearance of stainless steel, 30 seconds after the indicator bar appears on the blue dot is the disagreement.