1. Serious work hardening layer
Stainless steel is the most prominent work hardening phenomenon of austenitic and austenitic + ferritic stainless steel, because stainless steel has high plasticity, elements are distorted during plastic deformation, and the strengthening coefficient is large, and austenite is not stable enough. Under the action, part of austenite is transformed into martensite;
In addition, under the action of cutting heat, the chemical and material magazines are easily decomposed and distributed, and a hardened layer is generated during cutting. The smooth progress of a process;
2. Cutting tools are easy to wear
In the process of stainless steel cutting, due to the effect of affinity, there is adhesion and diffusion between the chips, so that the tool produces adhesion and diffusion wear, resulting in a crescent on the front face of the tool, and the cutting edge will also form a smile. In addition, the hardness of carbide particles in stainless steel is very high, and the direct contact with the tool during cutting will rub and scratch the tool, and the phenomenon of work hardening will aggravate the tool wear;
3. The cutting force of the lathe is large
The cutting force used by the lathe to process stainless steel is large, the plasticity of stainless steel becomes larger during the cutting process, and the work hardening of stainless steel is serious, which further increases the cutting resistance, and the curling and breaking of cutting is also difficult;
4. Cutting is not easy to break and easy to bond
Because the plasticity and toughness of the material are very large, continuous cutting during lathe processing not only affects the smooth execution of the operation, but even the chips will crush the processed surface. Under the action of high temperature and high pressure, stainless steel and other metals Strong affinity, it is easy to produce adhesion and form built-up edge, so it further aggravates the wear of the tool and the phenomenon of tearing, which is the deterioration of the machined surface, and the characteristics of martensitic stainless steel with low carbon content are more obvious;
5. Large coefficient of linear expansion
The linear expansion coefficient of stainless steel is as much as 1.5 times that of carbon steel. Under the action of cutting temperature, the workpiece will be thermally deformed one by one, so the dimensional accuracy of the workpiece is difficult to control;
6. The cutting temperature is very high
When cutting stainless steel, the plastic deformation and the friction between the tools are very large, so too much cutting heat is generated. In addition, the thermal conductivity of stainless steel is very low, and a large amount of cutting heat will be concentrated on the interface between the cutting area and the chip, resulting in The heat dissipation conditions are very bad;