Effect of Vanadium on the Microstructure and Properties of YQ450NQR1 Higher Strength Weathering Steels

The target-oriented researches on the vanadium-containing YQ450NQR1 high strength weathering steels were conducted in this paper.Methods such as optical microscope,high resolution electron microscope, phase analyzing,and so on were used to investigate the effect of vanadium on microstructure and the behavior of vanadium precipitates on the hot-roiling samples.The relationship between the amount of vanadium precip- itates and properties was analyzed.It has been found that the microstructures of test steels are composed of block ferrite and pearlite,vanadium is obviously precipitated from steel,the precipitates consists of VN or V （C,N）particles primarily.It is also obviously that the yield strength of steel can be raised after adding vana- dium into steel which is close correlated with the content of nitrogen.The content of vanadium can be brought down so long as higher precipitation proportion of VN is obtained.