Essentail In APL

In stainless steel mills, stainless strips are processed in a continuous Annealing and Pickling Line (APL) for treatment after the cold working.

The Annealing process provides a substantially heat treatment which can refine stainless steel strips.  This process however, due to the high heat, causes improper oxidation, scale and heat tint which must then be treated by the Pickling process.

In Pickling process, the stainless strips are fed through a continuous bath of Sodium Sulphate (Na2SO4) and Nitric Acid (HNO3). In order to accelerate this process, we apply a procedure called “Electrochemical Pickling” in which the steel strip is passed between pairs of anodes and cathodes where an electric current is sent.

Along with increasing temperature of the acid bath, this process removes impurities, such as scale, rust and stains resulting in high productivity and uniformity in steel strip surface quality.  This important process enhances the naturally self-passivate ability of stainless steel.

Due to the corrosive nature of the baths, the electrodes which have a steel base structure, is coated with either Lead or Silicon to provide corrosive protection while retaining the ability to conduct electricity.

The adhesion methods of the lead or silicon onto the steel base are critical. ME has cumulated years of experiences and keeps improving better methods of adhesion. With outstanding workmanship ability, ME ensures providing longer lifetime and better quality products than our competitors.