Method for electroslag welding of copper blanks

Claim 1

A METHOD FOR ELECTROSLAG WELDING OF COPPER BLANKS EMPOLYING A SLAG BATH CONTAINED IN A POCKET FORMED BY A BASE PLATIC, SUPPORTING BLOCKS UNDER THE COPPER BLANKS, THE COPPER BLANK SURFACES TO BE WELDED, COVERING BLOCKS RESTING ON TOP OF THE COPPER BLANKS AND BACK-UP PLATES COVERING THE SIDES OF THE GAP BETWEEN THE COPPER BLANKS, SAID METHOD COMPRISING THE STEP OF POURING A MOLTEN FLUX COMPRISING ALKALI METAL AND ALKALINE EARTH METAL FLUORIDES INTO SAID POCKET TO FORM A SLAG BATH, IMMERSING A NON-CONSUMABLE ELECTRODE INTO SAID SLAG BATH, APPLYING VOLTAGE ACROSS SAID NON-CONSUMABLE ELECTRODE TO HEAT THE SLAG BATH UNTIL THE BLANK EDGES BEING WELDED START MELTING, REPLACING THEE MONOCONSUMABLE ELECTRODE BY A CONSUMABLE, LAMINATED COPPER ELECTRODE TO ESTABLISH A MOLTEN METAL BATH, DIRECTING A STREAM OF COOLANT ON SAID MOLTEN METAL BATH AS IT EMERGES INTO THE GAP BETWEEN THE BLANK SURFACES TO BE WELDED IN ORDER TO COOL THE WELD BELOW ITS CRYSTALLIZATION FRONT, WHEREIN SAID BASE PLATE, SUPPORTING BLOCKS, COVERING BLOCKS AND BACK-UP PLATES ARE FORMED OF A HEAT-INSULTAING MATERIAL BEING A MORE ACTIVE OXYGEN ABSORBENT THAN COPPER AND HAVING A THERMAL CONDUCTIVITY LOWER THAN COPPER, SO THAT THE HEAT OF THE SLAG BATH IS RETAINED AND COMPLETE FUSING OF THE WELD METAL AND COPPER BLANCNK METAL OCCURS.

Claim 2

A METHOD FOR ELECTROSLAG WELDING OF COPPER BLANKS EMPOLYING A SLAG BATH CONTAINED IN A POCKET FORMED BY A BASE PLATIC, SUPPORTING BLOCKS UNDER THE COPPER BLANKS, THE COPPER BLANK SURFACES TO BE WELDED, COVERING BLOCKS RESTING ON TOP OF THE COPPER BLANKS AND BACK-UP PLATES COVERING THE SIDES OF THE GAP BETWEEN THE COPPER BLANKS, SAID METHOD COMPRISING THE STEP OF POURING A MOLTEN FLUX COMPRISING ALKALI METAL AND ALKALINE EARTH METAL FLUORIDES INTO SAID POCKET TO FORM A SLAG BATH, IMMERSING A NON-CONSUMABLE ELECTRODE INTO SAID SLAG BATH, APPLYING VOLTAGE ACROSS SAID NON-CONSUMABLE ELECTRODE TO HEAT THE SLAG BATH UNTIL THE BLANK EDGES BEING WELDED START MELTING, REPLACING THEE MONOCONSUMABLE ELECTRODE BY A CONSUMABLE, LAMINATED COPPER ELECTRODE TO ESTABLISH A MOLTEN METAL BATH, DIRECTING A STREAM OF COOLANT ON SAID MOLTEN METAL BATH AS IT EMERGES INTO THE GAP BETWEEN THE BLANK SURFACES TO BE WELDED IN ORDER TO COOL THE WELD BELOW ITS CRYSTALLIZATION FRONT, WHEREIN SAID BASE PLATE, SUPPORTING BLOCKS, COVERING BLOCKS AND BACK-UP PLATES ARE FORMED OF A HEAT-INSULTAING MATERIAL BEING A MORE ACTIVE OXYGEN ABSORBENT THAN COPPER AND HAVING A THERMAL CONDUCTIVITY LOWER THAN COPPER, SO THAT THE HEAT OF THE SLAG BATH IS RETAINED AND COMPLETE FUSING OF THE WELD METAL AND COPPER BLANCNK METAL OCCURS.