Relationship of roughness of abrasively worn out surfaces to abrasive resistance of metal materials

摘要

The mechanism of wear processes studied by degrading processes of abrasively degraded surfaces proves itself to be dependent on the structure of metal materials. The abrasive environment impacts on the metalic surface by mechanical effects of commonly deforming tine surface layer by rusting, scratching, and plastic deformations and consequent fatigue processes. In moist abrasive environment even chemical processes can be a corroborating factor. The above mentioned impacts alter the surface morphology in dependence on mechanical properties and on the structural composition of materials. The evaluation of surface morphology enabled to explain the mechanism of degrading processes under defined conditions and helped at the selection of abrasion resistent materials. A practical solution of a specific tribological problem requires the most suitable material to be selected operatively on the basis of tribometrical tests and their evaluation. When studying the surface morphology the authors also devoted their attention to the roughness of abrasively worn out surfaces and pronounced the hypothesis concerning tine possibility to utilize the roughness of the worn out surface as comparative criterion for tine asessment of material resistance against wear. Laboratory wear tests of steels with austenitic, ferritico-perlitic, ferritico-sorbitic and martensitic structures and of alloyed white cast iron were performed to prove the validity of the hypothesis. Wear was evaluated on tine basis of the mass decrease. The relative resistance against wear was related to steel with ferritico-perlitic structure. Roughness was measured on worn out surfaces and macrohardness of samples was measured complementary. The measuring results are presented in Table 1 and graphically evaluated in Fig. 6 and Fig. 7. It is substantialy possible to state on the basis of the result evaluation that the hypothesis was proved and to accept tine roughness of worn out surfaces as tine criterion of wear resistance. The schematically visualized graphical result evaluation (Fig. 7) of the surface roughness measurements, mass decrease as result of wear. and similarly that of hardness and relative wear resistance are corresponding (Fig. 6). The pressure increase on a surface undergoing abrasive degrading increases the surface roughness. Chemical influences during tine abrasive wear process decrease tine surface roughness. The extent of experiments and modifiacions of tine tested material structures enabled to pronounce potentially useful conclusions for the tribological practice.