Method for treating steel parts which are already galvanised and have a zinc layer, in particular for reprocessing used galvanised steel parts, apparatus therefor, and reprocessed galvanised steel part

Abstract

The present invention relates to a method and an apparatus for treating already galvanized steel parts having a zinc coating, in particular for remanufacturing used galvanized steel parts. The method comprises the following steps: A) checking the galvanized steel part for suitability with a view to remanufacturing; B) preparing the galvanized steel part mechanically and/or chemically; and C) rejuvenating the zinc coating of the steel part.

1 . A method for treating already galvanized steel parts having a zinc coating, in particular for remanufacturing used galvanized steel parts, comprising the following steps:
 A) checking the galvanized steel part for suitability with a view to remanufacturing;   B) preparing the galvanized steel part mechanically and/or chemically; and   C) rejuvenating the zinc coating of the steel part.   
     
     
         2 . The method of  claim 1 , wherein in step A) the galvanized steel part is checked with a view to at least one of the following properties:
 type of the existing zinc coating;   condition of the existing zinc coating;   degree of contamination;   type of deposits, in particular salts, oxides, hydroxides, greases;   concentration of deposits, in particular of salts, oxides, hydroxides, greases;   deformation of the galvanized steel part compared to its original initial shape;   type of corrosion of the galvanized steel part;   degree of corrosion of the galvanized steel part;   wear of the galvanized steel part;   material thickness of the galvanized steel part;   marking of the galvanized steel part;   presence of a fastening option, in particular a bore and/or a thread and/or a hole and/or an elongated hole;   condition of a fastening option, in particular a bore and/or a thread and/or a hole and/or an elongated hole;   color of the galvanized steel part;   presence of dissimilar coating materials;   material and/or material quality of the galvanized steel part.   
     
     
         3 . The method of  claim 1 , wherein step A) is performed using at least one optical and/or mechanical and/or inductive and/or electrical and/or chemical measuring device, in particular a camera, or/and by visual inspection. 
     
     
         4 . The method of  claim 1 , wherein step B) comprises a sub-step of cleaning the galvanized steel part. 
     
     
         5 . The method of  claim 4 , wherein the cleaning comprises at least one of the following cleaning steps:
 subjecting at least portions of the galvanized steel part to a blasting treatment using a blasting material, for example sandblasting or water blasting, in particular high-pressure water blasting, or dry ice blasting,   treating at least portions of the galvanized steel part by abrasion and/or brushing,   treating at least portions of the galvanized steel part by applying a cleaning substance,   dipping at least portions of the galvanized steel part into a cleaning bath,   treating at least portions of the surface of the galvanized steel part with a laser.   
     
     
         6 . The method of  claim 1 , wherein step B) comprises the following sub-steps:
 measuring the galvanized steel part for deviations from nominal dimensions,   checking whether the deviations are within specified tolerances,   corrective forming of the galvanized steel part if deviations exceed the specified tolerances.   
     
     
         7 . The method of  claim 6 , wherein the step of corrective forming comprises at least one of the following sub-steps:
 cold forming by pressing;   cold forming by rolling, in particular flat rolling or profile rolling;   cold forming by bending;   re-punching bores and/or holes and/or elongated holes;   adding bores;   cutting threads.   
     
     
         8 . The method of  claim 1 , wherein step C) comprises at least one of the following sub-steps:
 cleaning the galvanized steel part;   pickling the galvanized steel part using a pickling agent, in particular an acid containing zinc or a hydrochloric acid;   rinsing the galvanized steel part in a water bath;   fluxing the steel part, in particular dipping the steel part in a flux, preferably in an aqueous salt solution;   drying the steel part;   re-galvanizing the steel part, in particular by dipping the steel part into a zinc bath;   post-processing the re-galvanized steel part, in particular cooling the re-galvanized steel part.   
     
     
         9 . The method of  claim 1 , wherein the galvanized steel parts are preferably cold-formed or hot-rolled steel parts, in particular used guard rail components of vehicle restraint systems or parts thereof or used scaffolding parts or used steel girders or body parts of vehicles or used portable structures or galvanized substructures of, for example, greenhouses or, for example, trapezoidal roof coverings or sheet pilings. 
     
     
         10 . The method of  claim 1 , wherein the galvanized steel part is composed of a plurality of individual parts, preferably a plurality of similar individual parts, particularly preferably a plurality of individual parts connected with or without connecting means. 
     
     
         11 . An apparatus for treating already galvanized steel parts having a zinc coating, in particular for remanufacturing used galvanized steel parts, and in particular for performing the method of  claim 1 : 
     
     
         12 . The apparatus of  claim 11 , comprising
 a station for checking the galvanized steel part for suitability with a view to remanufacturing;   a station for preparing the galvanized steel part mechanically and/or chemically; and   a station for rejuvenating the zinc coating of the steel part.   
     
     
         13 . The apparatus of  claim 12 , wherein at the station for checking the galvanized steel part for suitability with a view to remanufacturing, the galvanized steel part is checked with a view to at least one of the following properties:
 type of the existing zinc coating;   condition of the existing zinc coating;   degree of contamination;   type of deposits, in particular salts, oxides, hydroxides, greases;   concentration of deposits, in particular of salts, oxides, hydroxides, greases;   deformation of the steel part compared to its original initial shape;   type of corrosion of the steel part;   degree of corrosion of the steel part;   wear of the steel part;   material thickness of the steel part;   marking of the steel part;   presence of a fastening option, in particular a bore and/or a thread and/or a hole and/or an elongated hole;   condition of a fastening option, in particular a bore and/or a thread and/or a hole and/or an elongated hole;   color of the steel part;   presence of dissimilar coating materials;   material and/or material quality of the steel part.   
     
     
         14 . The apparatus of  claim 12 , wherein the station for checking the galvanized steel part for suitability with a view to remanufacturing comprises an optical and/or mechanical and/or inductive and/or electrical and/or chemical measuring device, in particular a camera, or/and an area for visual inspection. 
     
     
         15 . The apparatus of  claim 12 , wherein the station for preparing the galvanized steel part mechanically and/or chemically comprises a sub-station for cleaning the galvanized steel part, wherein the sub-station for cleaning the galvanized steel part performs at least one of the following cleaning steps:
 subjecting at least portions of the galvanized steel part to a blasting treatment using a blasting material, for example sandblasting or water blasting, in particular high-pressure water blasting, or dry ice blasting,   treating at least portions of the galvanized steel part by abrasion or brushing,   treating at least portions of the galvanized steel part by applying a cleaning substance,   dipping at least portions of the galvanized steel part into a cleaning bath,   treating at least portions of the surface of the galvanized steel part with a laser.   
     
     
         16 . The apparatus of  claim 12 , wherein the station for preparing the galvanized steel part mechanically and/or chemically comprises a sub-station for measuring the galvanized steel part for deviations from nominal dimensions, further comprises at least one sub-station for checking whether the deviations are within specified tolerances, and further comprises at least one sub-station for corrective forming of the galvanized steel part if deviations exceed the specified tolerances. 
     
     
         17 . The apparatus of  claim 16 , wherein the sub-station for corrective forming is configured to form the galvanized steel part by carrying out at least one of the following sub-steps:
 cold forming by pressing;   cold forming by rolling, in particular flat rolling or profile rolling;   cold forming by bending;   re-punching bores and/or holes and/or elongated holes;   adding bores;   cutting threads.   
     
     
         18 . The apparatus of  claim 12 , wherein the station for rejuvenating the zinc coating of the steel part comprises at least one sub-station configured to perform at least one of the following sub-steps:
 cleaning the galvanized steel part;   pickling the galvanized steel part using a pickling agent, in particular an acid containing zinc or a hydrochloric acid;   rinsing the galvanized steel part in a water bath;   fluxing the galvanized steel part, in particular dipping the galvanized steel part in a flux, preferably in an aqueous salt solution;   drying the galvanized steel part;   re-galvanizing the steel part, in particular by dipping the galvanized steel part into a zinc bath;   post-processing the re-galvanized steel part, in particular cooling the re-galvanized steel part.   
     
     
         19 . A galvanized steel part, in particular a cold-formed or hot-rolled steel part, preferably a used guard rail component of a vehicle restraint system or a part thereof or a used scaffolding part or a used steel girder or a used body part of a vehicle or a part of a used portable structure or a part of a sub-structure or trapezoidal roof coverings or a sheet piling, which has been treated according to the method of  claim 1 .