| Cored wire technology is an effective micro-alloy method, it's more valuable in today, for more attention at conservation and reasonable using of resource. Vanadium nitride is an important alloy additive in metallurgical industry. V-N micro-alloying technology can increase the steel intensity significantly and reduce the cost of steel. Panzhihua Iron and Steel Research Institute originated VT (vanadium-titanium) cored wire in 2005, uses for adjusting the chemical element composition when melting some steel. And the utilization rate of V increase by 5%, N element utilization increased by 20% than before, so it has higher value. While there have been existing a problem of uneven core powder density since VT cored wire was commissioned, the main reason is that the fine vanadium nitride powders produced a bridge in funnel by which to feed to steel strip, what hinders the powders down flowing at even speed, so the phenomenon occurs. And because of the fine dust are excessively many, the vanadium nitride lost in a big way in the broken process, is also has more serious effect to the factory situation environmental.For that, starting from the broken process, it's the main process of the fine powders been produced. First, through uniaxial broken in the laboratory, studied the broken mechanism; then through the laboratory lithofacies, observed the internal structure characteristics of vanadium nitride;contact the experiments and working procedure of broken processes, analyzed the working procedure's characteristics; and introduced the fractal dimension to describes the characteristics of the powders and the breaking effect, Using Matlab to processing SEM images and calculating the particle size distribution of the fragmentation powders, got the fractal dimension, and expanded the using of fractal dimension in the actual broken working.Through the laboratory broken, found that the sintering of vanadium nitride broken in different ways when forced in different directions, by the vertical pressure force it's mainly transgranular brittle fracture, by the lateral pressure force it's mainly brittle fracture along the grain, and by the cross-pressure force its brittle fracture was mutual co-existence of the coupling;by the lithofacies, found the material is obvious stratification and anisotropy;by the study of breaking production process, found each working procedure has the different function, and the second-pass fine jaw crusher is the main process of produced the fine powders, therefore propose to abolish this process, and ultimately authentication is valid, the fine rate (below 0.6mm) dropped to 30%.In the final process of the roller, the fine powders in the feeding is not the main reason for more powders, so proposed to take the feeding to roll crusher directly, improved the production efficiency, reduced the loss of vanadium nitride and lower the effect to environmental.By the lithofacies analysis, observed the sintering characteristics of the internal structure of vanadium nitride, and using Matlab to processing SEM images to obtain its cross-section fractal dimension number, expressed as the maximum volume fraction dimension number was 2.73230, it's bigger than the results of particle size distribution of the fragmentation fractal dimension. Structure decision final product grain-size and characteristic was verified once more. By sieving experiment and particle size distribution fractal dimension, we can see that the fractal dimension number is directly proportional to the powder content below 0.6mm, and is inversely proportional to the middle particles of 3-1mm, it's good conforms to the product request characteristic, so it can be using for the production of the product indicators. Each broken working procedure's powders fractal dimension number is also various, and there is a strong correlation, it also can be using as a guiding indicator of the broken process.
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