In semi synthetic and microemulsion cutting fluids, formula developers often use chlorinated paraffins as extreme pressure additives for cutting fluids. Because chlorinated paraffins have excellent extreme pressure properties and low prices, metal cutting fluids have excellent extreme pressure properties and good cost performance.
The extreme pressure performance of chlorinated paraffin is good, but its lubricating effect is average. Today, we use the tapping torque to test. It can be seen from the numerical value that: A and B both add 40% lubricating oil content, and B also add 10% chlorinated paraffin, Mcrotap tapping torque meter
The tapping torque tests the strength of the physically adsorbed lubricating film. Lubricants and oily additives will form a layer of lubricating film on the surface of the workpiece. This layer of lubricating film plays a lubricating role by adsorbing lubricating oil molecules or polar molecules of oily additives on the metal parts to form an adsorption film. As an extreme pressure additive containing chlorine, chlorinated paraffin decomposes under high temperature and high load conditions to produce chloride ions, which react with metal parts to form a layer of metal chloride reaction film to play a heavy load bearing and anti-wear role, which is not reflected in tapping torque detection. This can also analyze the action mechanism of extreme pressure additives, that is, chlorinated paraffins can not play a very good role in lubrication under low temperature and low load conditions. When the cutting load increases, and high temperature and high load conditions, the extreme pressure lubrication effect of chlorinated paraffins will be significantly improved, and the accuracy of machined parts and tool protection will be greatly improved. Therefore, the tapping torque tester can well analyze the performance of the lubricating additives, especially for the lubricating performance of water-based cutting fluid and the selection of water-based lubricating additives.
