Traditionally, special grinding equipment and processes are required to machine parts with material hardnesses up to or exceeding HRC45. Today, with the steady development of machine tools and cutting tool technology, more new processes are being offered to component manufacturers, and more and more manufacturers are exploring new processing solutions that are suitable for them. For many applications, hard part turning has several advantages over grinding: in general, the cost of turning centers is lower than that of precision grinding machines, and multiple parts of parts can be machined in the same machine, greatly improving operation. Flexibility; reduced tool inventory, and turning centers are easier to integrate with automation systems than grinding machines. In addition, the chips generated during the turning process can be reused, and the fine chips generated by the grinding must be processed. Although grinding can be machined to tolerances within ± 0.005 mm, hard part turning has proven to be an excellent process technology for most other applications. When manufacturers decide to benefit from hard part turning, the following key aspects should be considered. Machine tool design Machine tools are critical to the successful turning of hard parts. Currently, most machine tool builders offer machine modules specifically designed for optimum machining performance. Regardless of whether you are considering a new investment machine or a machine tool, there are several factors to consider: The machine base will greatly affect the machining rigidity, and the cast iron or cast iron reinforced base provides optimum stability. The turret structure of the machine tool also affects the turning of hard parts. Ideally, manufacturers will focus on the rigidity of the turret and the integrated modular shank system, which helps reduce vibration by shortening the tool overhang. To optimize their performance, the integrated modular shank system should be circumferentially clamped instead of being clamped against two screws. Finally, depending on the specifications of the machined parts, it is necessary to carefully consider investing in machine tools with tailstocks. Because the part overhangs more than four times the diameter (counted from the chuck), the tailstock must generally be used for consistency and stability. "soft state" preparation When considering hard part turning applications, the “soft state preparation†of the part has a huge impact on the overall machining success. A consistent "input" is required to get a consistent "output". Before the hardening, the remaining part of the part should be uniform. Each processing plant tends to focus only on the quality of the final product, ignoring this critical factor. As a result, the cutting depth is affected by different cutting conditions, which directly affects cutting quality, tool life and production efficiency. In hard part turning, removing 0.0008 inch or 0.0012 inch of material will exert a large external force on the tool, which will impair the overall processing stability. The same applies to the hardness of the material. Parts with a hardness of 58 HRC are different from those for a hardness of 62 HRC parts. Although these variables are acceptable for finished parts, they should be avoided as far as possible for processing efficiency and utility. In addition to ensuring the consistency of the materials and dimensions of the various parts, manufacturers should look for better design methods to prepare the parts to be hardened. If possible, any holes, keyways and grooves should be chamfered. This reduces the impact stress during tooling and machining by smoothly entering and exiting the tool during interrupted cutting. Blade selection Blade selection is one of the first considerations when turning a hard part with a knife. Carbide inserts can process materials with a hardness of 40 HRC - 50 HRC and have good performance, making them a good choice for low hardness range materials. Common hardness ranges from 50 HRC to 55 HRC include low carbon steel with low carbon content. These materials are generally hardened on the surface and therefore require a high resistance to crater wear. Ceramic inserts are an excellent choice for this type of application. Materials with hardness exceeding 55 HRC, including case hardened steel and most integral hardened steel, require special flank wear resistance. CBN (cubic boron nitride) excels in the roughing and finishing of this type of material. The second hardest material known to man, cubic boron nitride, has excellent wear resistance and can cope with the adverse effects of high cutting temperatures. For materials with hardness higher than HRC 55, it is important to determine how much carbon content CBN is used. Materials with high carbon content are very abrasive, so the material composition of the insert should be higher in cubic boron nitride and lower in ceramic binder - this minimizes the flank wear of the insert, but A lower cutting speed of about 400 ft/min is required to avoid crater wear. Conversely, for low carbon content materials, flank wear is not a major problem. Consider using a CBN insert with a ceramic binder that is highly resistant to crater wear, typically at speeds in the range of 600 ft/min. Foam Polishing Pad ,Foam Buffing Pad,Foam Polishing Pad For Drill,Sponge Polishing Pads Shaoxing Ziyuan Polishing Co., Ltd. , https://www.zypolishcn.com