Comment on your observations regarding the hardness variatio

Comment on your observations regarding the hardness variations during machining and chip formation shown in Figure 1.

Chip 316 Built-up edge A Hardness (HK) 49 -289 371 A8 684 .383 ,656 574 261 289 70451339565 229 317 201 Workpiece 230

Solution

By observing the figure it is obvious that the chip undergoes a very high degree of strain hardening, which is evidenced by the hardness distribution in the chip. Also it is observed that the built-up edge has higher level of cold work, which is almost three times the workpiece hardness.