Application of thermodynamics in designing of advanced automotive steels

Abstract

Advanced automotive steels were designed with alloy concept and thermodynamics. Several phases were taken for the designing of transformation induced plasticity(TRIP) steels in accordance with the practical metallurgy process. Al was firstly chosen to substitute Si for improving galvanizing property, afterwards P was proved to be another alternative of Si by thermodynamic calculation and kinetic estimation. Thermodynamic investigation in the third phase revealed the effective function of Al to increase carbon solubility in austenite as well as TRIP effect of steel. Stack fault energy was calculated, in combination with heat treatment and microstructure measurement, which led to a successful composition designing of twin induced plasticity (TWIP) steel.

Keywords

Thermodynamics / Phase diagram / Materials designing / Advanced steel

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