Search Results

Advanced high strength steels (AHSS), such as dual phase (DP) and transformation induced plasticity (TRIP) steels, have been used successfully for making light weight vehicles and their usage is growing. Now, the automotive industry is expanding the use of AHSS to higher strength levels for further mass reduction. In a 2003 SAE paper, the material and formability characteristics for such steels were presented for steel grades of DP980, high yield type DP780 (780YM), low yield type DP780 (780YL), TRIP780, and TRIP590. In this study, experiments were conducted to assess the formability of these high strength steels using a T-channel, which incorporates several different forming modes in automotive stamping. The feasibility of computer simulation technology for the formability analyses of AHSS is also addressed.

In this study, to confirm the practical advantages and acceptability of galvannealed TS800MPa grade dual-phase steel (DP800), crashworthiness and spot weldability as important properties in practical use were investigated and compared with conventional galvannealed TS440MPa grade and microalloyed TS600MPa grade steels, which are currently used for frame parts. The results have shown that DP800 has high absorbed energy on crash tests, and has almost the same acceptable weldability as comparative steels.

Advanced high strength steels (AHSS), such as dual phase (DP) and transformation induced plasticity (TRIP) steels, have been increasingly used in automotive industry. One of the major advantages of AHSS is the excellent crash energy absorption capability. In this study, crash performances were evaluated for four AHSS including DP980, DP780, TRIP780 (780T), and TRIP590 (590T). Axial crush and bending crush tests were performed to evaluate the material crush performance. High strain rate tension test results for those materials were also presented. FEA analyses with parameter sensitivity studies were conducted including strain rate sensitivity effect, part geometry effects, welding models and forming effects. Good correlations between simulation and experimental data were achieved.