US 12,257,617 B2
Preforming method for high-strength steel variable-diameter tubular part
Guannan Chu, Weihai (CN); Lei Sun, Weihai (CN); Wencai Xie, Weihai (CN); Cunsheng Zhang, Weihai (CN); Anying Yuan, Weihai (CN); Gang Fang, Weihai (CN); and Qin Yang, Weihai (CN)
Assigned to Guannan Chu, Weihai (CN); and HARBIN INSTITUTE OF TECHNOLOGY, WEIHAI, Weihai (CN)
Filed by Guannan Chu, Weihai (CN); and HARBIN INSTITUTE OF TECHNOLOGY, WEIHAI, Weihai (CN)
Filed on Jul. 28, 2022, as Appl. No. 17/876,184.
Claims priority of application No. 202210195399.8 (CN), filed on Mar. 1, 2022.
Prior Publication US 2023/0278091 A1, Sep. 7, 2023
Int. Cl. B21D 26/047 (2011.01); B21D 26/053 (2011.01); B21D 37/16 (2006.01)
CPC B21D 26/047 (2013.01) [B21D 26/053 (2013.01); B21D 37/16 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A preforming method for a high-strength steel variable-diameter tubular part, comprising:
selecting a tubular blank; and
preparing a tubular blank forming mold, wherein the tubular blank forming mold comprises a preforming mold and a final forming mold;
sealing and pressurizing the tubular blank;
heating the tubular blank by using electrodes;
preforming the tubular part at a constant temperature, wherein performing the tubular part comprises heating the tubular blank to a temperature T; enabling the temperature T to be larger than or equal to 300° C., and smaller than or equal to 1200° C.; maintaining the temperature T of the tubular blank for 5-20 s, then closing the preforming mold; compressing the tubular blank; and opening the preforming mold after the tubular blank is compressed;
maintaining a temperature T1 and moving the preformed tubular part to the final forming mold, wherein maintaining the temperature T1 and moving the preformed tubular part to the final forming mold comprises continuously maintaining the temperature T1 of the preformed tubular part for 5-20 s, enabling the temperature T1 to be larger than or equal to 700° C., and smaller than or equal to 1300° C., and then moving the preformed tubular part to the final forming mold; and
finally forming the tubular part.