wear behavior of tib2 inoculated 20cr–3mo–4c high chromium white cast irons.doc

wear behavior of tib2 inoculated 20cr–3mo–4c high chromium white cast irons Wear behavior of TiB2inoculated 20Cr–3Mo–4C high chromiumwhite cast ironsSerdar Osman YilmazReceived: 3 January 2006/Accepted: 12 December 2006/Published online: 26 April 2007? Springer Science+Business Media, LLC 2007AbstractFeTi,B2O3,Al,andFeWparticulates,approximately 40–60 lm in size, were mixed in stoichi-ometric ratio and sintered at 1,200 ?C. The sintered par-ticulates were added as 5 wt% to molten high chromiumwhite cast iron over 50 C-deg above the melting temper-ature, and stirred at 1,000 rpm. The samples were inves-tigated in three groups: (1) high Cr white cast ironinoculated by the particulates sintered from Al–FeTi–B2O3particulates; (2) high Cr white cast iron inoculated by thesintered particulates derived from Al–FeTi, B2O3, and FeWparticulates; and (3) specimens of the second group thatwere subsequently homogenized. The microhardness ofceramic particulates was measured as 2,800–3,400 HV10.The effect of sintered particulate volume fraction on theabrasive wear resistance of the high chromium white castiron was determined. The wear resistance and hardness ofthe composites improved significantly as a result of par-ticulate inoculation. The application of the homogenizationheat treatment to the inoculated samples produced amicrostructure having homogeneously distributed particu-lates.IntroductionMaterials having high chromium concentration are used ina variety of applications including the mining and mineralprocessing, and cement production industries. These alloyshave high abrasive wear resistance; hence, these alloys areused for applications where grinding, milling, and pumpingapparatus are required to process hard materials such asore, coal, gravel, and cement. The abrasive wear resistanceof these materials is high due to hard carbides in thestructure [1–4].The alloys having high Cr contents have proeutecticand/or eutectic M7C3carbides in a softer iron matrix. Thema