Study On Properties And Material Properties Of Special Microalloyed Iron

Powder metallurgy is a technique that use powder as a raw material, through compacting, sintering and other techniques to get the material which has its certain characteristics. Iron powder occupies a very important position in powder metallurgy. In recent days, iron powder has been over 70% usage in all of powders. Kunming Iron and Steel Factory produced the special microalloy iron powder by using reduction - Grinding election. The vanadium-titanium magnetite concentrate has been reducted, the iron oxide parts has been turned into iron powder while vanadium and titanium still maintain the oxide state. Then products would be fine grinded to obtain high-quality iron and vanadium-titanium-rich material by way of sorting.In this paper, four batches of different process steps of the special micro-alloyed iron powderhas been studied. Using different temperature annealing, and different time of ball milling to study the factor of compressibility of powder, such as morphology, particle size, plastically. And annealed powder has been sintering to study the grain size affected compressibility or not.Compared with four kind of iron powder and annealed powder, microhardness significantly inversely correlated with iron compression. The higher microhardness, lower powder compressibility. Comparative morphology of Swedish iron powder and micro-alloyed iron powder, as well as micro-alloyed iron milled, particle morphology rearrangement stage effects are more obvious. Relative to the typical cavernous Swedish iron powder, and after milling was rough flaky iron powder, micro-alloyed iron oval original flat, atypical sponge morphology shows more excellent compression. Powder particle size ratio shows an obviously effects on the stage of rearrangement. But for powder plastic deformation stage, a simple rule has been proved: the bigger powder particles, better compression at higher pressures.Microhardness of iron powder depends on chemical composition, grain size, strain. After the special micro-alloyed iron reduction annealing at different temperatures, the grain size estimated by XRD, establish grain sizecompression sexual relations can be drawn. Grain size and powder compressibility positively correlated, the greater the powder grain size, the lower the hardness, better the compressibility. At higher pressure, soften powder would be more easily deformed. However, the grain size is also effect on the densification of the sintering process. In actual production, there has no need increase the grain size to change the compressibility of powder.