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Avesta Bath Pickling is used to restore larger stainless steel surfaces that have been damaged by working operations such as welding, forming, cutting and blasting.
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The pickling bath also removes welding oxides, the underlying chromium-depleted layer, micro-slag particles and other contaminants that may cause local corrosion. To assist pickling, this process may sometimes be combined with some form of simultaneous mechanical treatment, for example brushing.
After pickling, the workpiece should be thoroughly rinsed with clean water. The best results are achieved by using a high-pressure water jet. |
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To avoid smut formation and instantly restore the protective chromium oxide layer, a final passivation/decontamination step (using Avesta 630 or 601) is recommended.
Avesta Bath Pickling follows the recommendations of ASTM A-380 A.1 and BS CP-312. |
The bath pickling operation can be improved by using equipment for recycling the consumed acids and for stirring and heating the bath.
Products and equipment
 Avesta Bath Pickling 302 - is a concentrate that should be diluted with water depending on the steel grade.
Standard steel grades: Mix 1 part 302 into 3 parts water. A further dilution can be made if longer pickling times can be accepted.
High alloyed steels such as duplex grades and austenitic grades for use in severe corrosive conditions (904L): Mix 1 part 302 into 2 parts water.
Very high alloyed steels such as the super-austenitic (254 SMO) and super-duplex (SAF 2507) grades: Mix 1 part 302 into 1 part water.
Avesta Acid Recycling Unit makes it possible to recover up to 95% of the pickling acids by separating the free acids and the metal salts. This means an important reduction of waste quantities and acid consumption.
Avesta-BML Neutralising Facility is a batch working facility for treatment of pickling acids and rinse water
Avesta-BML Bath Stirrer
Avesta-BML Pickling tank, custom built sizes.
Avesta-BML Bath Heater - is a highly efficient and space saving teflon-coated heating element which is maintenance free, easy to install and offer maximum safety with thermal protection.
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