The definition of hard turning
Commonly referred to as hard turning haggard hard steel turning as the final processing or finishing process, in order to avoid the grinding technology are commonly used today. Hardened steel usually refers to after quenching marten site, high hardness, high strength, almost no plastic material of the work piece. When hardened steel hardness> 55HRC, the intensity sb about 2100 ~ 2600N/mm2. Typically, the work piece has been completed before the heat treatment hardened the roughing process, only finishing in the hardened state. Finishing grinding is the most commonly used process, but its narrow range of processing, investment, low productivity, easy to cause environmental pollution, has been plagued by cost-effective processing of hardened steel. Hard turning instead of grinding has become possible, and achieved significant benefits in production. Currently using polycrystalline cubic boron nitride (PCBN) cutting tools, ceramic cutting tools or coated carbide cutting tools in the lathe or turning center for machining hardened steel (55 ~ 65HRC), its precision up to 5 ~ 10 & micr0; m rms value of surface roughness average of less than 20 &micr0; m.
The carved characteristics of hard car
High processing efficiency
Hard turning has a higher processing efficiency than grinding, and the energy it consumes 1/5 of the ordinary grinding. Hard turning often with a large depth of cut, high speed of the work piece, the metal removal rate is usually 3 to 4 times of the grinding. Turning in a single setup to be completed by a variety of surface processing (such as car cylindrical hole inside the car, car slot, etc.), while grinding you need to install multiple times, so time is short, its auxiliary, the positional accuracy between the machined surfaces.
Hard turning is a clean process
In most cases, the hard turning without coolant. In fact, the tool life and surface quality of the use of coolant would adversely affect. Hard turning is formed by the shear part of the material annealed to soften the cutting, if the cooling rate is too high, it will reduce this effect produced by the cutting force, thereby increasing the mechanical wear and shorten tool life. Hard turning device eliminates the need for coolant, lower production costs; simplify the production system, the formation of the chip clean recycling easy.
Less investment in equipment, suitable for flexible production requirements
Productivity for the same lathe investment grinder 1/3 to 1/2, and its auxiliary system costs low. Hard turning without special equipment for small batch production and batch processing precision parts you need to play good rigidity, positioning accuracy and repeatability of positioning accuracy of CNC machine tools.
Lathe is a kind of processing a wide range of flexible manufacturing, fast, turning clamping with a variety of cutter wheel or knife library of modern CNC lathe processing.