Stainless  Restora‚Äčtion Ltd

Metal Finishing and Surface Engineering Technologies

SRL Technical Library

PICKLING AND PASSIVATION TROUBLESHOOTING  During, following or indeed before the cleaning operation all sorts of strange things can occur as a result of the chemicals used. Our technical library gives a variety of examples that SRL has encountered along its way. This list is by no means complete - these pages will be continually updated as we/you experience other strange phenomena.

Green Acid


Pickling - Green Acid

After a short period of use the pickling acid (paste, gel or liquid) will turn green as a result of the Chrome oxide that is building up in the solution. The Chrome oxide is one of the many metal salts that is being dissolved from the surface are a result of the pickling operation (controlled corrosion).

Possible Detriment

There is no problem with this happening, indeed, green is for "go" and indicates that all is well and that pickling is underway. In colder environments the surface may only turn a light green indicating the pickling rate is slower.

If the green acid is not removed properly it will turn brown and then appear as a "tea" stain - see trouble shooting section on "tea" staining.

Technical Notes

It is important to follow the instruction given for each individual product used and the advice given in the "product application data sheets" available on line in the product section of SRL Chemical and Analytical Services Ltd.

Information given in this page may be subject to alteration without notice.

Care has been taken to ensure that the contents of this publication are accurate but SRL Site Services Ltd do not accept responsibility for errors or for information that is found to be misleading.

Suggestions for, or descriptions of, the end use or application of products or methods of working are for information only and the company accept no liability in respect thereof.

Before using products supplied or manufactured by the company the customer should be satisfied of their suitability.

If further assistance is required, we have access to extensive research facilities, we will often be willing to help.

Stainless Restoration Ltd, Adamsons Industrial Estate, Hyde SK14 1EE

Stainless Restoration Ltd offer an Electropolishing service to the stainless steel fabrication/manufacturing industry at its newly refurbished fully automated Electropolishing plant at Hyde Manchester.