GB1072152A - Forging method - Google Patents

Abstract

1,072,152. Forging; working at specified temperatures. MASSEY-FERGUSON Ltd. June 3, 1964 [June 17, 1963], No. 22895/64. Headings B3H and B3V. A hot steel or alloy steel workpiece 70 is forged between closed dies 18, 32 for at least one second in the temperature range of 1600- 1800‹ F. The workpiece, which is particularly of steel alloy, is pre-heated to 2100‹ F. in a salt bath containing sodium and potassium chlorides and is then coated with lubricant by immersion in a mixture of flaked graphite and potassium iodide or by dipping into dry flaked graphite. Dies 18, 32 made of heat-resistant metal or coated with a ceramic, are insulated from the press parts 24, 26, 34 by refractory layers 22, 30. Each die is surrounded by induction heating coils 60 containing cooling fluid passages 62 and a temperature control 68 determines the supply of heat energy from source 58 or water coolant from supply 64 so as to maintain the die temperature in the range 1600-1800‹ F. After insertion of the hot workpiece the dies are closed by a hydraulically operated platen 10 and a plunger 40 is then actuated through lever 42 by an hydraulic ram 48 to further upset the workpiece into the shape of the closed die cavity. Finally the workpiece is removed by an ejector 50 operated by lever 54 and cooled down to below the critical temperature in a salt bath or mica pit.