In CNC machining, it is reasonable for almost all steel chips to appear purple during normal dry cutting. Today we will talk about the color changes of iron filings in CNC machining.

As the cutting temperature increases, the color change of iron chips during dry cutting follows the following pattern: silver white → light yellow → dark yellow → magenta → dark blue → blue → blue gray → gray white → purple black. The temperature change can rise from about 200 ℃ to over 500 ℃.

The process of color change of iron chips refers to the conversion of the majority of the work consumed during the cutting process into cutting heat, and can also be seen as the process of tool wear (sharpness passivation severe passivation scrap) (when there is no chip accumulation). Note that the cutting temperature we usually refer to is the average temperature.
The relationship between chip color and cutting temperature:
Silver white: below 200 ℃
Light yellow: ≈ 220 ℃
Deep blue: ≈ 300 ℃
Light gray: ≈ 400 ℃
Deep purple black:>500 ℃

When the cutting color is blue or blue purple, it is more reasonable. If it is silver white or yellow, the efficiency is not fully utilized. If it is blue gray, the cutting amount is too large. When using high-speed steel cutting tools, it is advisable to cut to silver white and slightly yellow. If cutting to blue, the speed or feed should be reduced.
Of course, determining reasonable parameters based on color changes is just one of the methods or means. Have you obtained it yet?

Transferred from - Mechanical Processing Trading Platform