In the machining of stainless steel parts, due to the cutting force and cutting heat of the workpiece, the physical and mechanical properties of the surface layer of the metal are changed. The most important changes are the changes in the microhardness of the surface layer metal and the changes in the metallographic structure. And the generation of residual stress.
Because the plastic deformation and cutting heat generated during grinding are more serious than those during cutting, the changes in the three physical and mechanical properties of the machined surface layer after grinding will be great.
(1) Factors that affect the surface roughness of cutting
There are three factors that affect the surface roughness during the machining of stainless steel parts: geometric factors, physical factors and process system vibration.
1. Replay of tool geometry
The main deflection angle, secondary deflection angle and increasing the radius of the tool tip arc can reduce the height of the residual area.
In addition, appropriately increasing the rake angle of the tool to reduce the degree of plastic deformation during cutting, rationally choosing lubricating fluid and improving the quality of tool sharpening to reduce plastic deformation during cutting and inhibit the generation of edge and scale spurs. Effective measure of surface roughness value.
2. The nature of the workpiece material
When the plastic material of stainless steel parts is processed, the plastic deformation of the metal is produced by the extrusion of the tool, and the tearing effect of the tool forcing the chip to separate from the workpiece increases the surface roughness value. The better the toughness of the workpiece material, the greater the plastic deformation of the metal, and the rougher the processed surface.
When processing brittle materials, the chips are in the form of crushed particles. Due to the crushing of the chips, many pits are left on the processed surface, making the surface rough.