A Rapid Heating Method for Press Hardening Processing

摘要

The work presents results of investigation on a new heating method for production of high-strength car body elements. It's proposed to substitute the conventional heating of blanks in gas or electric furnaces through the rapid contact heating. The blank at this process is pressed between two heated plates during few seconds and subsequently quenched in water-cooled dies to obtain high-strength properties due to the martensitic transformation. The influence of heating temperature in the range between 800 and 1000 ℃ and dwell time from 4 to 16 s on the microstructure and mechanical properties of 1 mm thick sheet of a low alloyed manganese-boron steel was studied. Furthermore, press hardening including common heating in electric furnace at 950 ℃ during 360 s and quenching in water-cooled dies of the same sheet was performed to compare the resulted microstructure and mechanical properties with the rapid heated and press hardened material.