The effect of 'tibal' on microstructure, wear and notch toughness of hyperotectic high chromium white cast irons

In this study the effects of TiBAl inoculants and heat treatments on microstructure andmechanical properties of hypereutectic high chromium white cast irons having two different chemicalconcentrations were studied. The samples having 4.21% C , 17.2% Cr, 2.51% Mo and 4.22% C,23.9% Cr were produced in two different chemical concentration. The microstructures of the sampleswere investigated by optical microscope and Scanning Electron microscopy (SEM). The chemicalconcentration of matrix and carbides were determined by EDS to detect the type of carbides andmatrix. Three different loads (10N, 20N and 30N) were used on a wear surface having 10X10 mm areaduring abrasive wear tests. The weight loss of samples was obtained by using a balance having 10-5 grsensitivity. The surface hardness of the samples was measured as HRC and average of threemeasurements. The toughness of the samples having the sizes of 10X10X50 mm was evaluated byusing Charpy V-notch specimens. The heat treatments were applied to the samples as (1000 oC)- 1 and2 h. Finally, the application of heat treatments and inoculations was shown that the best wearresistance was obtained for the samples having 1%TiBAl and Mo additions and as-cast condition. Theworst wear resistance was obtained from the sample having heat treatment (1000 oC-2h), 3%TiBAland without Mo additions.Key words: Hypereutectic High Chromium White Cast Irons, Inoculation, Wear Resistance.