Investigation on Friction and Wear Properties of High-Temperature Bearing Steel 9Cr18Mo

This paper presented a study of friction and wear on 9Cr18Mo when rubbed against other materials (steel-304, steel-440C, steel-GCr15 or silicon nitride ceramic ball) at high temperature conditions. Friction and wear tests were carried out with universal a friction and wear testing machine. The wear morphology was analyzed by a Nanovea three-dimensional profilometer and trinocular positive Gang metallurgical microscope. The Vickers hardness of 9Cr18Mo at different temperatures was tested by means of a high temperature vacuum hardometer. Results showed that the friction and wear on the contact surface of the 9Cr18Mo sample are higher when the hardness of counter materials is higher than or similar to that of the sample. Under dry sliding conditions, the 9Cr18Mo sample surface presented various degrees of adhesion, plowing and pit, particularly if tested in the presence of a high temperature environment. During the worn stages, the counter materials on the worn surface successively produced cracks, crack growth, and wear debris under the action of load. Moreover, the frictional pair 9Cr18Mo-ceramic showed good anti-wear behavior at 400 °C that proved the anti high temperature performance of 9Cr18Mo.