中文摘要：

为探明钢中微合金元素（V、Nb）与变形条件对含钒钢形变强化相变的影响规律，为制备含钒超细晶粒钢提供理论依据，通过对含钒钢进行形变强化相变热模拟试验，分析得出V、Nb的影响为：固溶V、Nb不利于形变强化铁索体相变的进行；V（c，N）、V—Nb（C，N）可以在多道次变形中沉淀析出，成为铁素体的异质形核核心，同时析出相对晶界及亚结构的钉扎作用使铁素体晶粒细化。研究表明，多道次变形时，道次间隔时间越短，温度越低，则累积的有效变形量越大，钢的形变强化相变越易进行，含钒钢超细晶铁素体体积分数越大。

英文摘要：

To provide a theoretical basis for producing ultra-fine grained steel and find out the effect of micro alloying element and deformation condition on deformation enhanced ferrite transformation in vanadium-alloyed steel, a deformation enhanced ferrite transformation （DEFT） thermal simulation test on vanadium-alloyed steel was carried out. The effect of V, Nb on DEFT was analyzed as two aspects： V, Nb solutionized in steel confine DEFT; on the other hand, V（C, N） and V -Nb（C, N） are induced precipitation by multiple-pass deforming, which provides nucleating center to intragranular ferrite （IGF）, meanwhile, V（C, N） and V - Nb（C, N） pinned substructure to make them steady, and simultaneity the substructure transforms to ultra-flne ferrite. The experimental results showed that the interval between multiple-pass deforming is shorter and the temperature is lower, then the accumulated deformation is larger, the DEFT is easier and the volume fraction of ultra-fine ferrite is greater.