Patent ID: 7285761

Claim:
Method for enhancing formability of a metallic workpiece ( 4 ) by means of electric current application to a workpiece to be formed by a subsequent forming operation at the elevated temperature by being compressed between a set of dies, the method characterised in that; controlling magnitute and timing of electric current with an electronic control unit ( 2 ) feeding primary coil of at least one transformer ( 1 ) with primary ( 9 )/secondary ( 10 ) coil ratio more than one, generating electric current at the second coil of said transformer(s) in a controlled manner, connecting said current to two electrode sets ( 5 ) contacting with two opposite sides of the forming area of said workpiece via two sets of the connections so that heat is generated inside said workpiece by transforming electric energy into heat energy until predetermined temperature at the workpiece is obtained, keeping temperature of the dies between a predetermined temperature range by taking away heat from the dies in a controlled manner, forming said workpiece between at least two dies by being compressed between said dies, achieving a predetermined heat transfer amount within a certain range from the workpiece to the dies while said workpiece is being compressed between dies, cooling of electrical connections ( 3 ) from said transformer to the workpiece including electrodes ( 5 ) contacting with said workpiece by means of cooling fluid flow, varying heat amount of taken away from the connectors and tools by variation of their actual temperature such that keeping their temperatures between their predetermined ranges.