The influence of surface preparation of steel components cut by thermal methods on the galvanizing process

In the presented paper the authors described findings regarding surface preparation effects upon the results of hot-dip galvanizing for metal components after cutting process. The aim was to determine the effect of additional heat - treatment performed after the oxy acetylene blowpipe (OAB) cutting on the structure and corrosion resistance of the zinc coating. The research was focused on one of fittings which finds application in overhead power lines - a double eyes link, SLINK's type, made of steel S355JR. Softening annealing was applied as additional treatment after cutting process using OAB. For comparison, grinding and electropolishing had been applied. In the next step, prepared materials were subjected to an abrasive blasting - steel shot GL40 and traditional chemical treatment. The hot - dip Zn galvanizing process was carried out in industrial conditions: temperature 457 degrees C, dipping time 2,5 min. The results confirmed, that application of a softening annealing after cutting with the oxy-fuel cutting is the most effective - the created zinc coating has the highest corrosion resistance. The application of the grinding and chemical methods (electropolishing) doesn't affect significantly both the structure and properties of the zinc coating.