Take you to understand some of the issues that should be paid attention to about spinning.
In the process of cooling the spinning parts from high temperature, due to the uneven volume change of the connected parts of the spinning process, they will restrain each other and generate internal stress. When the internal stress spinning material has the limit of strength, it will break; when the internal stress exceeds the yield limit of the material and does not reach the strength, the spinning part will deform; when the stress is less than the elastic limit, the residual internal stress will be The form exists in the spinning parts. Although there is nothing unusual on the surface of the spinning part, when the part is cut off during the cutting process, the original internal stress balance will be destroyed and the spinning part will also be deformed.
Spinning cylindrical parts often have defects such as diameter expansion, bell mouth, out-of-roundness, etc., which directly affect the dimensional accuracy and product quality of spinning parts. In actual production, the control of the dimensional accuracy of spinning parts mainly depends on experience. , Resulting in waste of manpower, material resources, and financial resources.
The diameter expansion of the blank during the spinning process and the fluctuation of its value are the main factors that affect the accuracy of the inner diameter of the spinning part. The diameter expansion not only causes a large error in the size of the spinning part, but also causes roundness errors and cylindricity error.
Under heating conditions, strong spinning will increase the process factors and make the process cumbersome, so cold spinning is generally used for metals with better plasticity. However, for refractory metals with poor plasticity, hot spinning processing technology is required. The heating temperature during powerful spinning of these materials is slightly the same as the heating temperature used in ordinary stamping. If the temperature is too high, recrystallization will occur. Recrystallization will make the crystal grains coarser and the fiber structure of the material will also be coarsened. This has a very unfavorable effect on multi-pass spinning processing.