Analysis of the difficulties and causes in the process of cutting


During the trial production of parts, our factory turned the 3Crl3 steel according to the technology of turning ordinary carbon steel. The result is that the tool wear is serious, the productivity is low, and the surface quality of the parts is not up to the requirement.
The mechanical properties of 3Crl3 steel and 40 steel, 45 steel and other carbon structural steel are compared. The strength, elongation, section shrinkage and impact property of 3Crl3 steel are all higher than those of 40 steel and 45 steel, which is a medium carbon martensitic stainless steel with high strength and good plasticity. Because of the severe working hardening during cutting, large cutting resistance and high cutting temperature, the tool wear is serious, which increases the number of grinding tools, increases downtime and machine adjustment time, and reduces productivity. Besides, it is easy to sticky knife, resulting in the accumulation of lump, causing the workpiece size change and affect the surface roughness, and chip is not easy to curl and break, but also damage the workpiece's machined surface, and directly affect the quality of the parts. Therefore, the process of cutting the 45 steel can not be used to cut the 3Crl3. The processing method on the general lathe can not be moved to the automatic lathe. Because the general automatic lathe has fewer knives, it is required that the best surface quality can be achieved at one time, so that the machined surface reaches the required size and surface roughness, so as to ensure higher productivity.