Ti与Nb微合金化汽车用钢二相粒子及织构研究

Study on Second Phase Particle and Texture of Ti and Nb Micro-alloyed Steel for Automobile

Ti与Nb微合金化汽车用钢中较大的二相析出粒子为方形的TiN,尺寸80~120 nm;较小的二相粒子主要为TiC、NbC及其复合析出物,尺寸12~25 nm;最小的析出粒子尺寸约3 nm,能谱分析为NbC。钢中析出的二相粒子均匀分布在基体中。试验钢的热轧织构主要由{001}<110>、{112}<110>、{111}<110>组分组成,同时也包含有γ和α组分,取向密度≥5。冷轧织构主要由高密度的γ织构和α织构组成,不稳定择优取向比热轧织构少。退火后组织中的α织构强度减弱,而γ织构呈管状分布且强度增加。从热轧到冷轧再从冷轧到退火,其织构具有遗传性。

The larger second phase particles in Ti and Nb micro-alloyed steel for automobile were square TiN with the sizes of 80~120 nm. The smaller second phase particles were mainly TiC, NbC and their composite precipitates with the sizes of 12-25 nm. The sizes of the smallest particles were about 3 nm and their chemical composition were NbC detected by energy spectrum analyzer. All of the second phase particles were evenly distributed in the matrix. The hot-rolled texture of the tested steel mainly consists of {001} 〈110〉, {1i2} 〈110〉 and {111} 〈110〉 components, T and a components with an orientation density of ≥ 5. The cold-rolled texture was mainly composed of the high-density T texture and a texture, and its unsteady preferred orientation was less than that of hot-rolled texture. The strength of ot texture weakened while the strength of the T texture increased and showed a tubular distribution after annealing. The texture was hereditary from hot-rolling to cold-rolling and from cold-rolling to annealing.