Papers by Keyword: Thread Turning

Abstract: With the development of the coating technology, coated tools have been widely used in processing industries. Thread turning is one of its applications. The performance of coated thread inserts varies with the change of coating material, coating thickness, matrix material and tool structure. Two tungsten-cobalt type alloy matrix, TiAlN coated thread inserts with different coating thickness, rake face type had been employed to conduct the thread turning experiments. By analyzing the cutting forces, chip formation and tool wear, it was found that insert with coating thickness of 4.35 μm would result in less tool wear under MQL condition, smaller cutting force, better chip morphology under dry condition compared with insert with coating thickness of 2.38 μm.

Abstract: Minimum quantity lubrication (MQL) is a new cooling technology used in machining process, which is friendly to environment and lower cost. This paper applied computational fluid dynamics (CFD) to analyze flow field of MQL in thread turning. Comprehensively applying droplet breakup method and capillary method, flow field of MQL in cutting zone were analyzed in detail. The results showed that oil mist could enter into cutting zone from sides of chip. And two vortexes existed around cutting zone which could reduce cutting temperature by accelerating heat exchange. Furthermore, flow rate of compressed air had great influence on velocity and diameter of droplets, velocity and pressure distribution of flow field. The effects of different flow rates indicated the larger flow rate was benefit for entering into cutting zone of oil mist.

Abstract: 13%Cr stainless steel has good comprehensive performance, which makes it suitable to work under the condition of high temperature, high pressure and corrosive environment, such as petroleum industry. It can be used as materials of petroleum pipes with buttress thread. Buttress thread turning is a heavy-load machining, which places high requirement on the cutting tool. Based on the cutting characteristics of buttress thread, the machinability of 13%Cr stainless steel is studied by turning experiments. Two kinds of inserts with different geometries were employed in buttress thread turning experiments. Experimental results show that less cutting force, longer tool life, better chip curling effect and surface quality was acquired for the insert with rake angle of 12° , clearance angle of 3° and chip-curling groove during 13%Cr stainless steel buttress thread turning process.