Manufacturing Automobile B Pillar by a Digitized Hot Stamping Production System

Abstract

For the manufacturing of high strength automobile body safety parts, a digitally controlled pilot production system for the hot stamping process was developed, including an electro-servo press, a numerically controlled heating furnace, a blank conveying system and a synchronized production line control system. By using the in-house developed hot stamping production system, automobile B pillars were manufactured from a proprietary high strength steel developed by Wuhan Iron and Steel (Group) Corporation. The steel blank was austenized in the furnace at 950°C for 5 min, followed by hot stamping. The overall cooling rate of the heated blank was above 35°C s-1 during the hot stamping process, which ensured a uniform martensitic microstructure with an average hardness above 460 HV1, a room temperature of tensile strength of 1489MPa and an elongation of 6.87%. The deviation of the formed part from the 3-D model is in the range between +0.623mm ~ -0.826mm.