METHOD AND APPARATUS FOR PROTECTING A WELDED METAL STRUCTURE AGAINST ELECTROCHEMICAL CORROSION Russian patent published in 2021 - IPC C23F13/00 B23K31/12 

FIELD: welding.

SUBSTANCE: invention relates to the field of production of welded metal structures and can be used in manufacture and repair of sheet, shell, tank, pipe, and frame, lattice metal structures resistant to electrochemical corrosion and made of interchangeable workpieces with similar thicknesses and physicochemical properties. In manufacture of a metal structure, the base potential of each workpiece is independently measured using an electrical measuring tool and a reference electrode. The measurement is conducted in a conductor assembled on the basis of a unit for measuring the thermoelectromotive force of a thermocouple manufactured from two electrodes: from the material of the workpiece and the material of the reference electrode. The measurement is conducted in a closed contour with several temperature drops between the working junction and the free ends of the thermocouple, whereat the metal structure is operated. For all temperature drops of each workpiece, the maximum base potentials of the workpieces are found. During assembly, the workpieces are arranged over the metal structure so as to minimise the average modules of the maximum algebraic differences of the base potentials corresponding to the maximum modulo values of the thermoelectric forces thereon based on the projected temperature drops between all pairs of adjacent workpieces, wherein if the base potentials of both workpieces have the same signs, then the algebraic difference is obtained by subtraction, and if the signs are different, by addition.

EFFECT: increase in the productivity of manufacture of welded metal structures is achieved with a reduction in the labour intensity of implementing protection against electrochemical corrosion.

2 cl, 3 dwg, 3 ex