Method of cleaning metal strip

Claim 1

IN THE METHOD OF CLEANING OXIDES FROM METAL STRIP FORMED FROM TITANIUM, TITANIUM BASE ALLOY, ZIRCONIUM AND ZIRCONIUM BASE ALLOY, THE STEPS COMPRISING, IMMERSING AND PASSING THE METAL STRIP THROUGH A HEATED CAUSTIC BATH IN AN IRON-BASE TANK TO EFFECT A REACTION BETWEEN THE ACUSTIC AND THE OXIDES, MAINTAINING THE METAL STRIP SUBMERGED IN THE HEATED CAUSTIC BATH BY MEANS OF A ROTATABLE HOLD-DOWN IRON-BASE ROLL DISPOSED IN ENGAGEMENT THEREWITH AND HAVING A PORTION THEREOF IMMERSED IN THE HEATED CAUSTIC BATH, THE IRON-BASE ROLL BEING ELECTRICALLY INSULATED FROM THE IRON-BASE TANK, THE METAL STRIP IN THE HEATED CAUSTIC BATH NORMALLY BEING AT POTENTIAL DIFFERENT FROM THAT OF THE IRON-BASE ROLL AND IRON-BASE TANK, CONNECTING THE IRON-BASE ROLL AND IRON-BASE TANK, CONNECTING THE IRON-BASE ROLL AND IRON-BASE TANK TO THE NEGATIVE TERMIKNAL AND THE POSITIVE TERMINAL, RESPECTIVELY, OF A SUPPLY OF CURRENT TO EFFECT A FLOW OF CURRENT THEREBETWEEN THROUGH A HEATED CAUSTIC BATH TO IMPART IRON-BASE ROLL A POLARITY DIFFERENT FROM THAT OF THE BASE TANK AND THE IRON-BASE ROLL IS SUBSTANTIALLY EQUAL TO THE NORMAL POTENTIAL BETWEEN THE IRON-BASE TANK AND THE METAL STRIP TO THEREBY SUBSTANTIALLY ELIMINATE ANY DIFFERENCE IN POTENTIAL BETWEEN THE IRON-BASE ROLL AND THE METAL STRIP AND PREVENT ELECTROYLIC PITTING OF THE METAL STRIP AS THE CAUSTIC REACTS WITH THE OXIDES OF THE STRIP IN THE HEATED CAUSTIC BATH.