Effect Of Rolling And Bending Deformation On Microstructure And Properties Of Metallic Materials

In recent years, with the rapid development of the international economy and the modern industry, the demand for metals in human society has become more and more large. The social demand for the metal amount increasing at the same time, some high performance metal or gold is more popular. In particular, lowconsumption of alloy resources consumption and the comprehensive performance of superior materialsalso receive a wide range of sought after and strong pursuit.It has indicated that the micro-structure of metals has a very important influence on the properties of metallic materials. The same material is processed in different ways and internal micro-structure changes and the mechanical properties of possible worlds apart. In order to obtain excellent performance, numerous scholars have done a lot of research.Grain refinement of metal materials is a very effective method to improve the mechanical properties and the performance of the metal. Severe plastic deformation is a very effective method to produce ultra-fine grain in recent years, which has been widely concerned by the industry. Although the traditional processing methods such as forging, rolling, extrusion can also be effective in grain refinement, but it is still difficult to meet the needs of the rapid development of society,especially for some high quality, high performance metal materials demand. With reference to the domestic and foreign large plastic deformation preparation status of ultra-fine grain materials, paper focuses on the rolling and continuous repeated bending deformation process (continuous cycling bending, CCB) combined into the effects of the properties of the metal. H85 brass with relatively high stacking fault energy of IF steel and low stacking fault energy as the object of study experimental analysis is carried out by finite element software MARC thatcalculates different curvature radius and plate thickness ratio (R/h, referred to as: diameter to thickness ratio) on the strain accumulated in metal specimen material to simulate the bending deformation. At the same time, wealso determine the variation regularity of the internal grain size by the micro-structure of experimental material analysis and determination of the micro-hardness. It can analyzethe advantages,disadvantagesand application prospect.After the cold rolling deformation, the grains are elongated in the rolling direction. When the deformation is larger, the strip micro-structure appears. When the pressure is less than 30%, the deformation of the specimen is not very uniform and only a part of the grain deformed. With the gradual increase of the amount of cold rolling, the orientation of the organization is becoming more and more obvious. The quantity of grain deformation also increases. When the rolling reduction is up to 50%, you can see the grain was flattened. When the rolling reduction rate reached 70%, it can be seen that the fibrous tissue in the sample was significantly thinner, the grain boundary samples become blurred, it is difficult to be identified. When the cold rolling reduction reached more than 80%, the grain of fish-bone within the organization changed into a banded structure parallel to the rolling direction. With the increase of the cold rolling reduction, the grain size of the sample is increased, the amount of the shear band is decreased and the grain size of the original specimen is broken. After repeated plastic bending deformation, the internal accumulation of the metal plate increases with the increase of the distance from the neutral layer with the increase of the distance from the neutral layer, the grain size becomes smaller and the micro hardness of the metal increases. With the decrease of the diameter to thickness ratio (r/h), the effect of accumulated stress is more significant. Due to the displacement of the neutral layer in the process of bending deformation, the strain can penetrate into the middle of the plate. So there is a certain amount of plastic deformation in the middle part. After the rolling reduction of 50% bending deformation, it can be further effective to improve the strain of the metal plate specimen. Itcan make the metal plate surface grain refinement of a few microns and the hardness increased to 250% of the original.