Chlorine in Metalworking fluids are additives in the form of a chloroparaffin or chlorinated olefin.
This is present as an extreme pressure (EP) lubricant in some metalworking fluids which are designed for use on ferrous metals.
It is believed that chlorinated olefins break down chemically under the influence of (extreme) heat and pressure near the cutting or grinding zone, to form a solid lubricant film between the ferrous work piece and the tool.
Although the same break down mechanism and film forming is unlikely in the case of aluminum, it has been observed that chlorinated olefins can help in the cutting or grinding of aluminum alloys, especially automotive alloys.
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