Papers by Keyword: Microalloyed Medium Carbon Steel

Abstract: Microalloyed medium carbon steels have been applied for auto forging products at the aim of lower cost since 1980’s in China. Without quenching and tempering processes, the cost of heat treatment was greatly decreased, so they are widely applied in car forgings such as crankshaft, connecting rod. Recently, with the aim of improving performance and reducing production cost, new technologies, such as: reductions of microalloyed elements, tailored components, and mechanical properties forecast, have been developed in China auto industry. The designation, processing, properties prediction and microstructure of auto components have been controlled comprehensively. With the development of new technologies, microalloyed medium carbon steel gradually began to be applied to product important parts, and replace Quenching and Tempering steels. Both steel makers and end product users are expressed their desire to share benefits of technological innovation. The technologies will have a huge developing space and very bright developing prospects in motor parts industry in future.

Abstract: A constitutive relation is proposed in this study by introducing a function prescrbing the volume fraction of dynamically recrystallized grains into the Voce’s equation to predict the stress-strain relations for three microalloyed medium carbon steels. We performed hot torsion test in temperature range of 900-1100 and strain rate range of 0.05-5.0s-1 to obtain the flow stress-strain curves. The calculated flow stresses are in good agreement with the measured ones. We have then applied the equations in FE analysis to predict the distribution of dynamic recrystallization volume fraction and flow stress for hot forging.