Pickling of stainless steel surfaces
The corrosion resistance of stainless steel can only be guaranteed when the surface is free of annealing colours (for example after welding), drilling emulsion residuals, rust film or ferrite impregnations after moulding processes. We recommend the use of acidic and alkaline degreasing/ cleaning products. (see products – cleaning and maintenance).
The pickling of stainless steel is a chemical process which thoroughly removes impurities and allows the formation of a new passive layer.
Depending on the actual task, structure and surface size of the stainless steel different pickling products are used.
- Pickling Paste
This is used for treating surfaces around the welding seam and it removes annealing colours, scale and corrosion products. From left to right the photos show: an untreated welding seam, application of the pickling paste with a paintbrush, the welding seam after the cleaning and rinsing procedures.
- Pickling Bath
This procedure is used for the efficient pickling of submersible structures, mounting and small serial parts, containers and devices.
- Pickling Spray
This is suitable for large surfaces (amongst others façade sheets, containers), non-removable structures or structures that are difficult to access such as bridge elements. An indicator can be added to the pickling spray to improve the control over the application.
- Ablation pickling
This special technology has the task of removing tensile and internal stress, as well as micro-cracks from parts by specifically removing 3-5 µm of the surface.>
For every one of the above-mentioned procedures Pelox offers various products depending on the level of contamination, the type of steel alloy used and the prevalent environmental conditions. You will find a detailed list under the browse button for products/ pickling products.
Regardless of the procedure or product used the surface that is to be pickled must be thoroughly rinsed, preferably with a high pressure cleaner. Furthermore we recommend that a passivation solution is applied to accelerate the formation of a new passive layer.