The study on lubrication action with water vapor as coolant and lubricant in cutting ANSI 304 stainless steel

Water vapor is a new type of environmental friendly coolant and lubricant. In this study, the friction test was carried out by using the water vapor as lubricant, and the friction pair was made of cement carbide K20 and ANSI 304 stainless steel. In order to study the lubricating action of water vapor as coolant and lubricant in cutting ANSI 304 stainless steel, experiments were carried out with K20 cutter. Through chemical state analyses of elements on tool–chip interface by means of XPS and Gibbs free energy calculation, the chemical reaction process was discussed between water molecule, oxygen atom and fresh tool–chip interface. Experimental results showed that an adsorption film and a tribo-chemical reaction film are formed on the tool–chip surfaces due to its excellent penetration performance and ability to form boundary lubrication layer. The multi-dimensional metal-oxide formed during the reaction weaken the mutual action between tool bulk material and chip. The cutting force and tool flank wear are reduced rapidly, and hence the tool wear is reduced about 50–75% compared with dry machining.