The Study On The Law Of The Recrystallization And Phase Transformation Of Two Phase Region On Trip Steel Of C-Mn-Al-P-La

Hyundai motor toward energy conservation, safe and economical, environmentallyfriendly, economical and other aspects of development. Application of highstrength steel in the car, can play a important role in more aspects of its performance thatautomotive required. Numerous studies in automotive steel says that high strength andlow alloy steel of the TRIP can be well positioned to meet these requirements.TRIP steel’s microstructure is mainly composed of ferrite, bainite andretained austenite. Effects of TRIP produce is to promote the metastable retainedaustenite,under stress conditions transforming to martensite, to ensure that theplastic while ensuring the strength, it is one of the ideal choice for automotive steel.In this paper, the TRIP steel studied is different from the traditional C-Mn-Si type.Al instead of Si can improve the oxidation resistance and hot surface plating. phosphorusinstead of silicon and manganese in steel can smaller the AC1、AC3temperature, andadding the retained austenite to resist the ability of bainite. Adding phosphorus also canincrease the content of residual austenite. Therefore, it is a worthy of studying forcomposition’s changing.It is designed different processes to test its laws on recrystallization andtransformation under the same components. The former is divided into dynamic and staticstate. Controlling different factors to determine the stress-strain curve by the thermalsimulation machine, and then obtaining the softening fraction. The deformation,temperature and rate are studied on static recrystallization. And the deformation rate andtemperature is studied on dynamic recrystallization.The experimental results show that the high temperature, the long pass interval andlarge deformation amount are beneficial to the recrystallization softening effect, while thehigh speed rate is conducive to the release of deformation storage energy. When thetemperature is higher, the impact of the high deformation rate is more obviously on thesoftening volume. At the heating rate of10℃/s, its temperature of Ac1and Ac3is separately740.7℃and1102.8℃. The austenite of the metal reached80.5%at1000℃.