Scuffing characteristics of wear resisting steel and steel with surface modification treatment

摘要

Wear resisting steel (WRS), improved scuffing characteristics was newly developed in order to apply to the frictional parts for machinary. The two rollers tests were carried out using the newly developed WRS, steels with Ni-P electroless plating, and with electrolyzed and sulfurizing treatment. Then the scuffing characteristics of these materials were discussed. The anti-scuffing characteristics of WRS were very good and the frictional coefficient was as small as about (1/3) of SUJ2, a reference material. From the test results using WRS specimen of two kinds of hardness, the anti-scuffing characteristics of specimen of which the hardness was low was higher. The anti-scuffing characteristics of steel with Ni-P electroless plating were good. The part of Ni-P electroless plating layer remained during the test period but the other part of plating layer disappeared. On the other hand, the electrolyzed and sulfurizing layer which is effective for running-in, disappeared in a short time, and became that of base material. As the result of observation of surface and cross section of specimen, the white layer on the scuffing surface was found from 30 to 50 μm thickness. It seemed that the layer is a martensite including supersaturatedly solidified carbon which is a part of cementite at the sub-surface dissolved by thermal and mechanical energies.