摘要
利用电子背散射衍射(EBSD)技术和高分辨透射电子显微镜(HRTEM)对不同和Mn含量的CSP工艺Ti微合金钢进行了显微组织分析与析出相特征观察.结果表明:与Ti和Mn含量较低的钢相比,Ti和Mn含量较高的钢中,不仅小角度晶界分布比例较高.同时颗粒尺寸在10 nm以下的TiC粒子析出数量显著增加.而较大尺寸的M_3C相(Fe_3C)析出数量却有所减少.此外,强化机理分析表明.细晶强化与位错强化对两实验钢的屈服强度贡献最大,而深沉析出强化是造成两实验钢强度差别的主要原因.
As an advanced manufacturing technology to produce hot rolled strips,compact strip production（CSP） process was developed at the end of the last century and has been widely applied due to its high efficiency and low cost.Compared with the traditional technology,the advantages of CSP technology benefit from the refinement of austenitic grains and precipitation strengthening in the steels.This is because cooling rate is higher during the solidification of slab and the direct charging slab temperature is also higher in the CSP process,resulting in much higher solute contents in the solid solution before hot rolling than expected by the experiences from traditional steel production. Therefore,the Ti microalloyed steels produced by the CSP process exhibit good performance and have drawn much attention to Ti precipitate behavior and strengthening mechanism.However,the influence of alloying element Mn on the Ti microalloyed steels produced by CSP.especially the synergistic effect of Mn and Ti,was rarely reported.Therefore,in this work the microstructure and precipitate characteristics of two Ti microalloyed steels with different Ti and Mn contents produced by the CSP process were studied by electron backscatter diffraction（EBSD） technology and high resolution transmission electron microscope（HRTEM）.The results show that the steel with higher Ti and Mn contents has a higher fraction of small-angle grain boundaries.Furthermore,the weight fraction of TiC precipitates with particle size smaller than 10 nm increases significantly,from 7.6%in the lower Ti and Mn steel to 26.1%in the higher Ti and Mn steel.However,the amount of Fe_3C precipitates decreases markedly. In addition,the strengthening mechanism analysis of the two tested steels shows that grain refinement strengthening and dislocation strengthening make great contribution to the yield strength,while the precipitation strengthening is the primary reason for the difference in the strength between two tested steels.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第12期1541-1549,共9页
Acta Metallurgica Sinica
基金
国家重点基础研究发展计划资助项目2010CB630805~~
关键词
CSP
TI微合金钢
强化机理
力学性能
compact strip production（CSP）
Ti microalloyed steel
strengthening mechanism
mechanical property
