USE OF VANADIUM IN STEEL

摘要

The addition of vanadium to steel results in a benefit to steel production and significant improvement in steel properties. Consumption of vanadium in steel has increased significantly in recent years and by 2002, the steel industry consumed about 85 percent of the world's output of vanadium. The largest use of vanadium is in high strength low alloy (HSLA) structural steels. Vanadium has been also used in a wide range of other steels including rail steels, high-speed tool steels, die steels and stainless steels. Vanadium produces its effects by increasing strength and improving toughness, primarily through a combination of grain refinement and precipitation strengthening. Because vanadium is the most soluble of the microalloying elements, vanadium containing steels tend to be relatively easy to continuously cast, require low reheating temperatures, can be rolled with no significant increase in rolling load over that required for C-Mn steels and their properties are relatively insensitive to finish rolling temperature. By using recrystallization controlled rolling, the hot rolled fertite grain size in vanadium microalloyed steels can be refined to ～4 μm. Recent studies have shown that the presence of vanadium in steel promotes ferrite grain refinement due to its effect on the nucleation of intra-granular ferrite during the austenite to ferrite transformation. In addition, vanadium improves the heat affected zone toughness by promoting a tough acicular ferrite microstructure. The objective of this paper is to review the results of research carried out by both Vanitec and others on the effects of vanadium on grain refinement and castability and of its use in reinforcing bar steels.