论文部分内容阅读
采用SEM、TEM以及XRD等技术研究了合金元素Al、V、Ti对1000 MPa级Fe-C-Mn-Si基TRIP钢显微组织和室温拉伸性能的影响。结果发现,添加钒-钛微合金元素可使钢中析出Ti C型碳化物纳米颗粒,产生析出强化作用,同时细化晶粒进一步提高TRIP钢的强塑积;通过热力学计算可以发现,添加Al元素会减少两相区奥氏体含量但可显著增加其碳含量,从而延迟贝氏体转变,增加残留奥氏体稳定性,提高TRIP钢的强塑积;此外,研究还对比了不同碳含量对TRIP钢力学性能的影响,结果发现,对于复合添加Al、V、Ti的TRIP钢而言,含碳0.3%左右的试验钢强塑积可达到25000 MPa·%以上,而碳含量降至0.21%时,后续冷却时组织中出现了马氏体相,TRIP效应减弱,力学性能明显降低。
The effects of Al, V and Ti alloying elements on the microstructure and tensile properties at room temperature of 1000 MPa grade Fe-C-Mn-Si based TRIP steel were studied by SEM, TEM and XRD. The results show that addition of vanadium-titanium microalloying elements can precipitate TiC-type carbide nanoparticles in the steel and produce precipitation strengthening effect, meanwhile refine the grains to further enhance the plasticity of the TRIP steel. Through the thermodynamic calculation, it can be found that addition of Al Element can reduce austenite content in two-phase region but can significantly increase its carbon content, thus retarding bainite transformation, increasing retained austenite stability and increasing the plasticity of TRIP steel. In addition, the study also compared the carbon content On the mechanical properties of TRIP steels, the results show that for the TRIP steels with Al, V and Ti addition, the plastic strength of the test steels with carbon content of about 0.3% can reach more than 25000 MPa ·% and the carbon content decreases to 0.21 %, The martensite phase appeared in the subsequent cooling, the TRIP effect weakened, and the mechanical properties decreased obviously.