TPT May 2017

AR T I C L E

Rivit SpA

by Willy Goellner, chairman and founder – Advanced Machine & Engineering/AMSAW HFree Life Pickling – a new industrial process that improves the environment and productivity By Loris Dal Santo, R&D Department, Rivit SpA, Italy

The tests led to excellent results, confirming in the large majority of cases the results claimed by Henkel in the first stage of testing. However, during this stage some criticality connected to the development of gases such as hydrogen and oxygen during the application of electric current to the electrochemical cell did emerge. These gases in fact tend to collect on the upper inner surface of the tube, giving rise to a volume of gas that prevents the contact of the electrolyte solution with the surface to be treated. Thanks to the plant changes, however, the problem was completely solved, obtaining a complete removal of the oxidised flake from the inner surface as well as from the external surface of the tube. During the tests, possible problems were identified connected to the dragging of the particles of the bath by the gases that develop during electrolysis. For this reason Rivit – thanks to the support from ARPAV and the Province of Vicenza – has identified a containment system for the emissions that will be used in the industrial pilot plant that is under construction in the Caltrano plant, a long-standing production unit in the manufacturing industry that produces stainless steel tubes.

HFree Life Pickling, a project co-financed by the European community through the instrument LIFE, represents the synergy between Rivit, Henkel and the Province of Vicenza, Italy, in the search for a new process that can help pickling productivity and improve the environmental impact of the process. In the first stages of the project, Rivit provided Henkel with various specimens of metal alloys to be heat treated. Thanks to the ability to work on realistic specimens, Henkel technicians were able to develop a new chemical solution devoid of toxic substances that has achieved reductions of more than 90 per cent in the laboratory yet still has the technical features to achieve a surface finish comparable to traditional pickling (see Figure 1). The results achieved in this early stage confirmed the poten- tial of the process from a production and environmental viewpoint. However, it was necessary to verify the performance during application with tubular geometries. To this end Rivit implemented a pilot “mini-plant” in the second stage by reduced scale in order to carry out tests on specimens of tubes of a length shorter than one metre. In recent years concerns about environmental issues have increased considerably within manufacturing industries. This is why the reduction of the environmental impact of the processes involved represents a critical goal for many companies. Interestingly, some of these environmental improvements can also bring economic benefits for the industry.

Figure 2: Specimen of the Tube UNS S31803

Figure 1: Finishing obtained through the “HFree” process – alloy UNS S32750

80

www.read-tpt.com

MAY 2017