The precision rolling process includes mold making, bar heating, finishing rolling, finishing and straightening and other processes. Compared with the existing rough rolling technology of cross wedge rolling, the material saving rate is increased by more than 10%, and the comprehensive mechanical properties of the parts are increased by more than 5%. The tolerance zone of the finished product produced by precision rolling is about 1/2 smaller than the international standard high-precision tolerance. The rolled bar and wire do not need to be drawn or cut, and can be directly ground due to the omission of the process. Therefore, the demand for precision-rolled steel is increasing year by year, especially for some high-quality alloy steel, whose raw material cost is high, and precision rolling will have its special significance.
Introduction
At present, there are many small tandem precision wire rolling mill machine in our country. The finished and pre-forming rolling mills are changed to short-stress line high-rigidity precision strip rolling mills or pre-stressed rolling mills, which improves the accuracy of the rolled material by one level, but this is different from the international precision rolling technology. There is still a considerable gap between the physical standards that are rolled out. The tolerance zone of the finished product produced by precision rolling is about 1/2 smaller than the international standard high-precision tolerance. The rolled bar and wire do not need to be drawn or cut, and can be directly ground due to the omission of the process. Therefore, the demand for precision-rolled steel is increasing year by year, especially for some high-quality alloy steel, whose raw material cost is high, and precision rolling will have its special significance.
Precision rolling process, which includes mold making, bar heating, finishing rolling, finishing and straightening and other processes. Compared with the existing rough rolling technology of cross wedge rolling, the material saving rate is increased by more than 10%, the comprehensive mechanical properties of the parts are increased by more than 5%, the straightness of the product is controlled within 0.02mm-0.04mm, and the product curvature is increased by 25% is reduced to 3% after one straightening. The special rolling curve designed and manufactured solves the rolling difficulty of the dense asymmetric concave step shaft, so that the cam side and journal of the camshaft can be achieved without machining. skills requirement
Features
As an important aspect of online product quality control, bar and wire rod reduction and sizing unit is also more and more valued by manufacturers. Alloy steel bars are usually precision rolled by reducing and sizing units. The bar reducing and sizing unit is usually 3 to 5 frames, the first two frames are used for the extension and deformation of the rolling stock, and the last few frames are used for the rolling stock sizing. The pass type of the 4-stand wire rolling mill machine is an ellipse-circle-circle-circle system. After using the reducing and sizing unit, the dimensional tolerance of the product can be controlled within ±0.001mm, or even up to ±0.005mm, and the ovality can be controlled within 60% to 80%, which can reach the tolerance value that can be achieved during secondary cold working. Therefore, Some machining steps can be omitted or simplified.
