The thickened part of the two ends of the thickened tubing is made by upsetting the tubing blank. In order to improve the applicability of the tubing blank, we must first control the wall thickness of the tubing stock. 2. Control the internal molding tools. 3. Control the forming size of the thickening die of the thickened external forming tool. 4. Control the heating of tubing blank and shorten the heating temperature of tubing end. 5. Control the quality control procedures such as deformation processing technology, so as to make the tubing thickening and upsetting roundness meet the needs of processing and manufacturing.
Secondly, in every upsetting process, including thickening transition zone, PDCA cycle procedure should be strictly followed. Through planning, implementation, inspection and disposal of the four links of circulation, step by step, gradually improve the product quality and process quality, adhere to the implementation of the quality control procedures of large circulation, small circulation, and continuously improve the quality level of tubing thickening and upsetting.