Abstract: A set of thermoforming equipment was developed by State Key Laboratory of Rolling and Automation， based on thermoforming with high inner atmospheric pressure theory， to study thermoforming process of ultra-strength steel pipes. The resistive heating was used to accurately control the temperature of the pipes. The high-pressure sealing structure of pipe ends， rapid inflation system and hydraulic servo system were designed. The heated pipes were shaped under the action of both high inner atmospheric pressure and axial feed. By means of the mold inner loop cooling circuit designed， the pipes touched the cold mold and were quenched directly. Therefore， pipe heating， forming and quenching were finished in single-position. The experiment results show that maximum gas pressure reaches 40MPa with the sealing effect reliable. Temperature control accuracy is ±1℃ and the inflation velocity can be adjusted continuously. The equipment provides reliable support for the research of ultra-strength steel pipe thermoforming process with inner high atmospheric pressure.

Key words: thermoforming equipment, ultra-strength steel pipe, thermoforming, inner high atmospheric pressure, high-pressure sealing, single-position