Heat in metal cutting
2000; Elsevier BV; Linguagem: Inglês
10.1016/b978-075067069-2/50007-3
Autores Tópico(s)Tunneling and Rock Mechanics
ResumoPublisher Summary This chapter focuses on the role of heat in limiting the rate of metal removal when cutting the higher melting point metals. The power consumed in metal cutting is largely converted into heat near the cutting edge of the tool, and many of the economic and technical problems of machining are caused directly or indirectly by this heating action. The bulk of cutting, however, is carried out on steel and cast iron, and it is in the cutting of these, together with the nickel-based alloys, that the most serious technical and economic problems occur. With these higher melting point metals and alloys, the tools are heated to high temperatures as metal removal rate increases and, above certain critical speeds, the tools tend to collapse after a very short cutting time under the influence of stress and temperature. It is, therefore, important to understand the factors, which influence the generation of heat. The most important heat source responsible for raising the temperature of the tool is the flow-zone where the chip is seized to the rake face of the tool. The amount of heat required to raise the temperature of the very thin flow-zone is a small fraction of the total energy expended in cutting, and the volume of metal heated in the flow-zone may vary considerably. Therefore, there is no direct relationship between cutting forces or power consumption and the temperature near the cutting edge.
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