MFE 201 Lecture Notes - Lecture 33: Ductile Iron, High-Speed Steel, Microstructure
31 Mar 2016
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Document Summary
Material removal introduction and shearing processes part 2. Heat in machining comes from the shearing process and friction of workpiece and tool and chip. The heat is distributed into the tool, workpiece, and chip. High temperatures on the face of the tool lead to wear and shortened life. Temperature increases in the part and tool can lead to dimensional inaccuracies in very tight tolerance situations. Notice that peak temperature in the tool does not occur at the tip, but rather away from it, due to a great extent to friction. This location is where crater wear occurs as will be seen later. The workpiece temperature also goes up, and without care it could be su cient to leave a heat a ected zone with di erent properties than the base metal. Lastly, the temperatures in the cutting tool are high enough to temper the tool if it is a high speed steel tool.
