Process for forging and forming welding neck flanges for connecting pipelines

The invention belongs to the technical field of forging of flanges and particularly relates to a process for forging and forming welding neck flanges for connecting pipelines. The process comprises the following steps: blanking, heating, preforming, forming and punching. An intermediate frequency furnace is used for heating blanks; the blanks are firstly preformed and upset into cake shapes afterbeing heated, and then the upset blanks are inversely placed into a forming die and are closed and formed; in the preforming process, a 1000T electric screw press is used for preforming and upsettingcylindrical blanks; then a neck part of a 2500T electric screw press forming die is filled by a punch; and 315T closed single-point punching is used for cutting off the connected skin and blanking. The process has the beneficial effects that accurate discharging is achieved after allowance is added to the finished product; the sizes of the forged products are uniform and controllable; stable batchproduction is realized; th