Техническая информация Sumitomo - страница 3

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Technical Guidance Turning Edition Tool Failures and Tool Life ■ Forms of Tool Failures Cat. No. Name of Failure Cause of Failure Mechanical Causes (1) to (5) Flank Wear Due to the scratching effect of hard grains contained in the work Resulting from material. (6) Chipping Fine breakages caused by high cutting loads or chattering. (7) Fracture Large breakage caused by the impact of excessive mechanical forces acting on the cutting edge. Chemical Reactions (8) Crater Wear Swaft chips removing tool material as it flow over the top face at high Resulting from temperatures. (9) Plastic Deformation Cutting edge is depressed due to softening at high temperatures. (10) Thermal Crack Fatigue from rapid, repeated heating and cooling cycles during machining. (11) Built-up Edge Adhesion or accumulation of extremely-hard work material on the cutting edge. ■ Tool Wear Forms of Tool Wear Flank Wear Crater Wear Bad chip control (mm) (mm) cutting edge fracture VB KT Burrs occur Width Initial wear Sudden Width Crater wear KT Wear increase Wear Poor surface finish Crater Wear Side flank wear in wear VN1 Flank Steady wear Flank Face flank wear VN2 Cutting Time T (min) Cutting Time T (min) Flank average wear VB Edge wear VC Flank Wear ・Wear increases rapidly right after cutting ・Wear increases in proportion to the Higher cutting force starts, it then progresses at a moderate and cutting time. Poor machining accuracy, proportionate pace up to a certain point Burrs occur where it suddenly increases rapidly again. ■ Tool Life (V-T) ・This double logarithm graph shows the relative tool life of the specified wear over a range of cutting speeds on the X-axis, and the cutting speed along the Y-axis. Flank Wear Crater Wear Flank Wear Width vc1 vc2 vc3 Crater Wear Depth vc1 vc2 vc3 vc4 Tool Wear (mm) vc4 (mm) KT VB T1 T2 T3 T4 T'1 T'2 T'3 T'4 Cutting Time (min) Cutting Time (min) Cutting Speed Invc1 Cutting Speed Invc1 (m/min) Invc2 (m/min) Invc2 Tool Life Invc3 Invc3 Invc4 Invc4 InT1 InT2 InT3 InT4 InT'1 InT'2 InT'3 InT'4 Tool Life (min) Tool Life (min) N References Technical Guidance / N11