Allegheny Surface Technology offers In-House and On-Site Pickling / Passivation services. We can pickle passivate inside or outside a tank, depending on the size of your product. Pickling is the removal of oxide layers resulting from welding and heat-treating.
In our building we have a specially designed containment area to process large components. This enables us to process nearly any part that can be transported to our facility. If this is not feasible we could deploy our On-Site crews to perform this treatment at your facility. For some applications electropolishing may be considered.
Electropolishing is a useful alternative to pickling. Metal removal is achieved by applying electric current to a part submerged in an electrolytic bath. Electropolishing usually creates a bright, smooth and more highly corrosion resistant finish.
Pickling is the chemical cleaning of metallic surfaces in order to remove impurities, stains or scale with an acidic solution. Allegheny Surface Technology uses pickling solutions consisting of nitric (HNO3) and hydrofluoric (HF) acids to remove the scale and underlying chromium depleted layers to restore the corrosion resistance of stainless steel. Mechanical removal of those imperfections may leave abrasive material or other particles embedded in the surface and in some applications mechanical polishing may be impractical.
Pickling is considered the preferred solution for the restoration of the corrosion resistance in stainless steel. Pickling will further create a uniform dull finish on the work piece. Allegheny Surface Technology is also capable of performing localized pickling. For those applications pickling pastes, where the solution is mixed with an inert carrier, are used to treat selected areas such as welds. Examples are parts that just need welds cleaned up or parts which have other than stainless steel components as part of the assembly.