Patents Assigned to Zincroksid S.p.A.
  • Patent number: 4548872
    Abstract: An improved process for the protection of flat rolled steel sections in the form of bands, plates or sheets in particularly aggressive environments is disclosed. According to applicant's copending U.S. patent application Ser. No. 585,856, filed Mar. 2, 1984, U.S. Pat. No. 4,520,077, steel plates previously plated with zinc or zinc alloys are, as such, plated with layers of an electrolytic plating consisting of inorganic elements or compounds, preferably chromium metal and chromium oxide. The improvement according to this invention comprises a chemical passivation in a chrome anhydride solution of the zinc base plating layer, prior to carrying out the successive multi-layer electrolytic plating of inorganic elements or compounds.
    Type: Grant
    Filed: July 24, 1984
    Date of Patent: October 22, 1985
    Assignee: Zincroksid S.p.A.
    Inventor: Carlo Lavezzari
  • Patent number: 4547268
    Abstract: Improved process for the production of coated steel sheet particularly suitable for the fabrication of car bodies, galvanized and further protected by a layer of metallic chromium and hydrated oxides of chromium. The improvement consists in optimizing process operating conditions, within certain limits, to obtain a protective layer of chromium and hydrated oxides of chromium with absolutely new morphological characteristics which endow the product with corrosion resistance far greater than that of similar products reported in the literature.
    Type: Grant
    Filed: February 10, 1984
    Date of Patent: October 15, 1985
    Assignee: Zincroksid S.p.A.
    Inventors: Roberto Bruno, Massimo Memmi
  • Patent number: 4520077
    Abstract: A process is disclosed for the protection of steel rolled sections, in form of rolls, sheets or plates, already plated with zinc or zinc containing alloys, by means of one or more layers of an electrolytic plating, consisting of inorganic elements or compounds, preferably metal chrome and chrome oxide.
    Type: Grant
    Filed: March 2, 1984
    Date of Patent: May 28, 1985
    Assignee: Zincroksid S.p.A.
    Inventor: Carlo Lavezzari
  • Patent number: 4511633
    Abstract: Steel sheet, especially suitable for car-body fabrication, galvanized and further protected by a layer of metallic chromium and hydrated oxides of chromium, electrolytically deposited. The improvement is that the metallic chromium is present in extremely fine particles that exert a very marked covering and protective effect on the underlying zinc. In this way, and with the help of the chromium oxides that further cover and protect the underlying layers, a product is obtained whose corrosion resistance is far superior to that of similar products.
    Type: Grant
    Filed: February 10, 1984
    Date of Patent: April 16, 1985
    Assignee: Zincroksid S.p.A.
    Inventors: Roberto Bruno, Massimo Memmi
  • Patent number: 4495008
    Abstract: Thin metal plate is cleaned and electrolytically pickled in an acid solution. A zinc layer is electrodeposited on one face of the plate, after which a chrome-chromic oxide coating is deposited on both faces of the plate from a sulphuric acid solution containing compounds of trivalent and exhavalent chrome. The plate is then subjected to a drying-oxidating treatment in air. The plate may be steel having a thickness between 0.1 and 2 mm. The plate may be surface treated by phosphating, and then painted. The chrome-chromic oxide coating may have a thickness between 0.05 and 5 .mu.m, and the zinc coating a thickness between 1 and 30 .mu.m.
    Type: Grant
    Filed: March 1, 1982
    Date of Patent: January 22, 1985
    Assignee: Zincroksid S.p.A.
    Inventors: Roberto Bruno, Massimo Memmi
  • Patent number: 4437944
    Abstract: Thin metal plate is cleaned and electrolytically pickled in an acid solution. A zinc layer is electrodeposited on one face of the plate, after which a chrome-chromic oxide coating is deposited on both faces of the plate from a sulphuric acid solution containing compounds of trivalent and hexavalent chrome. The plate is then subjected to a drying-oxidating treatment in air. The plate may be steel having a thickness between 0.1 and 2 mm. The plate may be surface treated by phosphating, and then painted. The chrome-chromic oxide coating may have a thickness between 0.05 and 5 .mu.m, and the zinc coating a thickness between 1 and 30 .mu.m.
    Type: Grant
    Filed: December 22, 1980
    Date of Patent: March 20, 1984
    Assignee: Zincroksid S.p.A.
    Inventors: Roberto Bruno, Massimo Memmi