Development of innovative manufacturing technology : chain-die forming for ultra-high strength steels

Abstract

In recent years, there is high demand for automotive manufacturers to design fuel-efficient vehicles without compromising passenger safety. One potential solution is to construct lighter vehicles using materials such as Ultra High Strength Steel (UHSS). However, its high-strength properties result in the difficulty to form desired profiles using traditional sheet metal forming processes such as Cold Roll Forming. To overcome this problem, a potential solution of Chain-die Forming (CDF) was recently developed. The basic principle of the CDF is to fully combine roll forming and bending processes, and its primary advantage was the elongated deformation length which significantly increases effective roll radius. In this study, three case studies were conducted to develop a reliable finite element-based numerical model of CDF with Advanced High Strength Steel (AHSS). These simulations demonstrated the effectiveness of this forming process while capturing the mechanical behaviours of AHSS. The numerical modelling and simulations served as Computer Aided Engineering (CAE) tools which determined tool geometries and to control unwanted springback. The experimental work conducted on novel 2nd Generation Chain-die forming machine. An automotive martensitic steel DOCOL 1400M from SAAB was adopted for this research as a typical AHSS material, which has a yielding strength of 1,150 MPa and a tensile strength of 1400-1600 MPa. According to the numerical simulations and experimental results obtained, CDF can be considered as an affordable, sustainable and environmentally friendly manufacturing process.

Date of Award	2019
Original language	English