Plastic deformation regularity of flange forgings
- Jan 29, 2018 -

The Basic Law of plastic deformation following the forging process of flange forgings.

1. Minimum Resistance law

The law of minimum resistance means that in the process of plastic deformation, the metal particles will move in the direction of least resistance if the blanks of the flange forgings are likely to move in several directions. The least resistance movement is the normal direction of the particle to the periphery of the metal deformation, because the particle moves in this direction in the shortest distance and the required deformation work is the least. The law of minimum resistance conforms to the general principle of mechanics, which is one of the most basic rules in plastic forming process. Using the law of minimum resistance, it can be inferred that any shape of an object with sufficient plasticity can be upset under a flat hammer to make the billet close to the circle gradually. This is because during upsetting, the shorter the metal flow distance, the less friction resistance. In the figure, the circular section of metal flows toward the radial direction, the square, the rectangular section is divided into 4 areas respectively toward the vertical and four sides of the flow, and finally gradually become circular, oval. It can be concluded that the flow of circular section metal in all directions is the most uniform, and the upsetting is always forged into a cylindrical body before forging.

2. The volume invariant law of plastic deformation is that the material of the flange forgings is unchanged before and after the plastic deformation. The metal plastic deformation process is actually the process of redistributing the volume of the billet through the flow of metal. But in fact, because the ingot can be forged to eliminate the internal micro-cracks, porosity and other defects, so that the density of the metal increased, so the volume will always have some reduction, but this volume change is extremely small, negligible.