Development of New Hot Forming Process for High Strength Steel Tubes

Abstract

The widely adopted the high strength steel tube is an important way to solve the lightweight body and collision safety. The traditional high pressure tube hydroforming and hot gas forming through “expansion” deformation to form hollow parts, and the internal pressure is the deformation driving force. There are some industrial difficulties such as heavy dependence on high pressure, wall thickness thinning and low production efficiency, which limits the production and application of high-strength steel tubes. Based on the principle of compression deformation, this paper develops the hot hydro-forging process to form the high-strength steel tubes. After the tube blank is heated to austenitization, the tube is compressed and deformed by the die closing force of the die through a new die structure. The internal pressure only plays a supporting role, which fundamentally avoids the thickness thinning and cracking under the expansion deformation mode, and has the advantages of rapid forming time and uniform quenching. Finally, the A-pillar tube with 1500 MPa is formed through the reasonable hot hydro-forging process.