Hot pressing technology of pipe fitting cap

　　For the pipe fitting cap of the hot-pressing, its initial temperature is 930-950 C hot-pressing temperature, the final pressure temperature should not be lower than 850 C, if the temperature dropped to close to 850 C still can not be pressed molding, should be quickly back to the furnace after heating and pressing. In order to avoid the decrease of bonding strength and corrosion resistance of clad steel sheet, the heating time should be shortened as far as possible. The holding time should be controlled within 20 minutes and the reheating times pipe fitting caps should not exceed 2 times. The workpiece should be heated rapidly or cooled at 550~850 C.

　　(1) In order to raise the heating speed of the workpiece and ensure uniform heating, the workpiece must be heated to 380 C before entering the furnace. The other workpieces should not be heated at the same time in the furnace, and the workpiece can reach 930 950 C within 15 minutes by properly adjusting the injection rate.

　　(2) heating the workpiece at the same time, preheating the die to 450~550 C.

　　(3) When the workpiece is discharged from the furnace, the preheated die is placed in the position of the press, and then the workpiece is quickly sent to the die for pressing. The cooling rate of the workpiece is slowed down by the heat of the die. Pipe fitting caps is controlled within 3 minutes from discharging to pressing to ensure that the final pressure temperature is higher than 850 C.

　　(4) starting from 380 degrees centigrade and heating to 930~950 C, the workpiece can be released from 930~950 C.

　　(5) In order to avoid the intergranular corrosion tendency of the cladding material, two large fans of 600-800mm can be used to blow the workpiece at the same time after the workpiece is pressed and formed, so that pipe fitting caps can be reduced to below 550 C within 3 minutes.