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Machining analysis of stainless steel tube in the thin wall of machinery industry
- Apr 16, 2018 -

In the machining industry, because of the poor rigidity of the workpiece, it is easy to produce vibration and deformation in the process of turning. The tolerance and dimension tolerance of the workpiece can not be guaranteed. If the solution is not proper, it can even make it impossible to carry on the process.

1. problems of processing

The machining of thin-walled parts is a difficult problem in turning. The reason is that the rigidity of the thin-walled parts is poor, the strength is weak, it is very easy to deform in the processing, and makes the shape error of the parts increase, and it is not easy to guarantee the quality of the parts.

Therefore, strict requirements are put forward for the clamping of thin-walled parts, the rational selection of cutting tools and the selection of cutting parameters.

thin-walled-stainless-steel-pipe2 .jpg

The thin-walled stainless steel pipe/tube we processed is the heat shock casing on the nozzle of a certain product. The workpiece belongs to the large diameter and thin wall workpiece, the outer diameter of the pipe is 292mm, the material Z2CND17-12 nitrogen control stainless steel, the thickness of the wall is 4mm, the total length of the workpiece exceeds 550mm (leaving the remainder), the roundness requires 0.05mm, and the total surface roughness is Ra=6.3 mu m, determined this The precision coefficient of the workpiece is very high.

2. formulation of processing technology

A. increase the technological chuck and lengthen the length from 550mm to 610mm..

B. division of the processing stage:

(1) the rough processing stage. Use rough and rough boring to remove the allowance. In rough processing, the amount of back knife and feed can be larger. When finishing, the amount of the back knife is generally in 0.2~0.5mm, the feed is generally in 0.1~0.2mm/r, even smaller, the cutting speed is 6~120m/min, the cutting speed is as high as possible, but it should not be too high.

(2) half processing stage. Prepare for the finishing of the main surface, finish some secondary surface processing, and use the semi finishing vehicle to achieve the necessary precision and processing allowance before finishing. If the tube is clamped on the chuck, the force will be too large, which will cause deformation of the thin-walled parts and cause the roundness error of the parts. If it is not tightly clamped on the chuck, it may cause loosening and scrapping when turning. When we take rough cars, we should clamp some of them and relax them when we finish the car, so as to control the deformation of parts. Semi finishing stage backcutting depth is small, the release of internal stress to thin-walled stainless steel tube, reduce the deformation of finishing.