论文部分内容阅读
采用OM,SEM和TEM对V微合金化钢与V-N微合金化钢的组织与析出相进行了分析,研究了强化机制.结果表明,V微合金化钢与V-N微合金化钢的显微组织主要为铁素体与少量珠光体的混合组织.随着卷取温度的升高,V-N微合金化钢的强度呈现出先增加后下降的规律,600℃时获得了最优的力学性能,其屈服强度与抗拉强度分别达到了605与687 MPa,延伸率为24.5%.与V微合金化钢相比,V-N微合金化钢的铁素体晶粒更细小,平均晶粒尺寸达到4.5 mm,析出相更细小弥散,尺寸在3~50 nm之间,平均尺寸达到8.0 nm,以及更高的位错密度.晶粒细化、析出强化与位错强化是V-N微合金化钢具有高屈服强度的主要原因,其中细晶强化是最主要的强化机制,占总屈服强度的43.05%,析出强化与位错强化对屈服强度的贡献高达34.44%.
The microstructure and precipitation phases of V microalloyed steel and VN microalloyed steel were analyzed by OM, SEM and TEM, and the strengthening mechanism was studied. The results show that the microstructure of V microalloyed steel and VN microalloyed steel Mainly composed of ferrite and a small amount of pearlite.With the increase of coiling temperature, the strength of VN microalloyed steel first increased and then decreased, the optimal mechanical properties were obtained at 600 ℃, The strength and tensile strength reached 605 and 687 MPa, respectively, with an elongation of 24.5% .Compared with V microalloyed steels, VN microalloyed steels have finer ferrite grains with an average grain size of 4.5 mm, The precipitated phase is more finely dispersed, the size is between 3 ~ 50 nm, the average size is up to 8.0 nm, and the dislocation density is higher. Grain refinement, precipitation strengthening and dislocation strengthening are the properties of VN microalloyed steel with high yield strength The main reason is that the fine grain strengthening is the most important strengthening mechanism, accounting for 43.05% of the total yield strength. The contribution of precipitation strengthening and dislocation strengthening to the yield strength is as high as 34.44%.