How to prevent the deformation of turning thin-walled parts?

The deformation of thin-walled parts in turning is multifaceted. The clamping force when clamping the workpiece, the cutting force when cutting the workpiece, and the elastic deformation and plastic deformation when the workpiece hinders the cutting tool, resulting in thermal deformation due to the increase of the temperature in the cutting area.

The cutting force is closely related to the cutting parameters. From the “metal cutting principle”, we can know that the back cutting amount AP, feed rate f and cutting speed V are the three elements of cutting parameters. During the test, it is found that:

1) When the back draft and feed increase at the same time, the cutting force increases and the deformation is also large, which is very unfavorable to turning thin-walled parts.

2) Reduce the back draft and increase the feed rate. Although the cutting force decreases, the residual area of the workpiece surface increases and the surface roughness value is large, which increases the internal stress of the thin-walled parts with poor strength and also leads to the deformation of the parts.

Therefore, during rough machining, the back feed and feed can be larger; During finish machining, the back feed is generally 0.2-0.5 mm, the feed is generally 0.1-0.2 mm / R, or even less, and the cutting speed is 6-120 M / min. When finishing, use the cutting speed as high as possible, but it is not easy to be too high. Reasonable selection of three elements can reduce cutting force and deformation.