Continuous pickling and galvanizing lines
By coupling the pickling line and galvanizing process in a single system ANDRITZ Metals is setting new trends in hot strip processing.
ANDRITZ Metals is a well established supplier of multi-process lines in both ferrous and not-ferrous industry. Combining high efficiency pickling, specific skin passing and the optimized heat-to-coat treatment within a single process line, the pickling and galvanizing line (PGL), gives the customer competitive advantage in terms of investment as well as operational costs and minimized environmental impact. This process set-up enables production of final galvanized hot strip with cold mill tolerances.
The line is equipped with numerous high-performance components. At first the scale of the incoming hot rolled material is cracked by bending around the work rolls of a scale breaker. In this way the strip is prepared for the subsequent chemical high efficiency pickling. Spray pickling sections at the entry and exit of the pickling tank are included in addition to the turbulence pickling to achieve a boosting effect. This function can individually be activated in order to meet the specific requirements and surface activity for downstream coating. Thickness tolerances and surface roughness are adjusted in the subsequent 4-high skin pass mill. In a heat-to-coat process the strip is heated to the minimum temperature to produce consistently good adhesion of the zinc coating with minimum H2 content in the protective nitrogen atmosphere. Adjustable hydrogen content and temperature in the furnace offer maximum flexibility for each type of surface. In order to provide a good zinc layer the strip leaves the furnace with well-adjusted temperature and enters the zinc pot and airknife. A second skin passing step is applied to the final product to further improve thickness tolerance and texture of the end product. Final surface finish is done with a coater where different passivation coatings are applied.
ANDRITZ Metals´ answer to market demands for high quality products using most economical and environmental friendly technology is this combined hot strip pickling and galvanizing line.
- optimized heat to coat treatment for hot strip at 5% hydrogen atmosphere
- adjustable temperature before pot
- patented inductor sealing arrangement
- competitive advantage in terms of investment, operational cost and quality