Process and die design for large deformation upsetting process of long steel tube

QIN Song-xiang
（Department of Mechanical and Electrical Engineering， Taizhou Polytechnic Institute， Taizhou 225300， China）

Abstract： Aiming at the problems of the machining process for the large deformation upsetting forming of long steel tube，the calculation and design of forging pressure processing were investigated. After the analysis of upsetting pressure process，the relationship between high-pressure pipe diameter ratio，upsetting pressure deformation and forging quality was established. A machining method was presented to solve the problems such as unstable and folding phenomenon for the upsetting pressure products. The possible instability of the stock and the outside and inside diameter of the products were evaluated on the process and die design，the upsetting pressure process was tested，moreover，the working process and precautions of the mold were provided. The results indicate that，if the ratio of height to diameter and upsetting pressure greatly exceeds the total deformation of upsetting pressure processing specification when long steel pipe upsetting pressure processing，the problems of the machining process for the large deformation upsetting forming of long steel tube can be solved using ways such as taking two upsetting pressure，the inner diameter of the blank with mandrel and the external diameter of blank with the design mode and blank circle for pickling，phosphating，coating of solid lubricant.
Key words： long steel tube；large deformation；upsetting；die design