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本文从研究控制轧制基础的角度出发,研究了控制轧制各个阶段中Nb(C, N)粒子的析出行为、状态、分布、结晶构造以及对钢的晶粒细化、沉淀析出强化的影响关系.主要结论如下:1) 控制轧制过程中,析出的Nb(C, N)的结晶构造因钢中(C+N)/Nb分子比值不同而不同,当此比值>1时,析出物为F.C.C.构造的δ相析出物,呈球形.2) 控制轧制过程中,Nb(C, N)首先从γ晶界、变形带界面上开始析出,然后普及到整个晶内析出.3) 在1050℃以上变形过程中,轧后γ晶粒再结晶的发生先于Nb(C, N) 粒子的析出,因此在这样高温下停轧待温将会得到粗大的部分再结晶γ晶粒,对钢材冲击韧性不利.4) 经60％变形后在1000～900℃之间待温时,只要能保证得到0.015％体积分量的Nb(C, N)析出就可以保证在200s之内防止γ晶粒粗大化.5) 轧后冷却速度过慢,将会引起在α相区域析出的Nb(C, N) 粒子长大,从而失去沉淀强化效果.
In this paper, from the perspective of control rolling, the precipitation behavior, state, distribution and crystal structure of Nb (C, N) particles in various stages of controlled rolling are studied, as well as the effects on grain refinement and precipitation strengthening of steel The main conclusions are as follows: 1) In the controlled rolling process, the crystallized structure of Nb (C, N) is different due to the ratio of (C + N) Is the δ-phase precipitates formed by the FCC, spherical.2) Nb (C, N) begins to precipitate from the γ grain boundary and deformation zone interface during the controlled rolling process, During the deformation above 1050 ℃, the recrystallization of γ grains before rolling occurs prior to the precipitation of Nb (C, N) particles, so stopping and warming at such a high temperature will result in coarse recrystallized γ grains The impact toughness of steel is unfavorable.4) When the temperature is between 1000 and 900 ℃ after being deformed by 60%, the precipitation of Nb (C, N) with a volume fraction of 0.015% can ensure that the γ grains are prevented within 200s Coarsening .5) If the cooling rate after rolling is too slow, the Nb (C, N) particles precipitated in the α-phase region will grow and precipitate precipitation will be lost fruit.