Structure, Mechanical Properties and Wear Resistance of High-vanadium Cast Iron

Abstract

A series of melts with carbon content 1.38-4.16 % and that of vanadium 5.25-15.50 % was made. The Xray diffraction of the examined alloys revealed the presence of three phases, i.e. ferrite, alloyed cementite, and VC x carbide. The relationships between the content of carbon and vanadium corresponding to eutectic structure (the eutectic line) as well as the degree of eutectic saturation S c were determined. Besides eutectics, the high-vanadium cast iron holds the following constituents in its matrix: alloyed ferrite, granular pearlite, and lamellar pearlite as well as a mixture of alloyed ferriteϩgranular pearlite, granular pearliteϩ lamellar pearlite. The results show that passing from ferritic matrix through granular pearlitic and to lamellar pearlitic matrix, hardness HB, tensile strength R m , and yield strength R 0.2 , increases while plastic properties of alloys represented by elongation A 5 decreases. The wear behaviour of alloys was tested in two different modes "specimen-abrasive paper" test (P1) and "specimen-counterspecimen" test (P2). The results obtained in test P1 are following: a) alloys with ferritic matrix and of the lowest hardness (182-189 HB) are characterised by the lowest abrasion wear resistance (sϭ3.14-3.93 mg/m), b) in alloys with a pearlitic matrix and hardness in the range of 387-416 HB the abrasion wear resistance is comparable to that of Hadfield cast steel (about sϭ2 mg/m) and c) cast iron with lamellar pearliteϩgranular pearlite matrix and hardness 322 to 401 HB gives the highest abrasion wear resistance of sϭ0.24-0.62 mg/m. In general, it can be stated that the abrasion wear in test P2 is higher than in test P1.

Microstructure Control of High-alloyed White Cast Iron

“…Fe-C-V alloys with high vanadium content are included in the family of white cast irons, because all carbon present in this material is bound into vanadium carbides. The results of microstructural examinations and of the mechanical and tribological tests carried out on these alloys are given in [5,6]. The analysis of available literature confirms the growing interest in common high-alloyed white cast iron [7,8], which offers a very good complex of tribological properties, but unfortunately has very low ductility.…”

Anisotropic in Situ Metal Matrix Composite Reinforced with VC Carbide Fibres

“…For this reason, for the in-situ composites, regular types of eutectic are selected [1,2]. The vanadium eutectic crystallising in Fe-C-V alloys is known to be in the group of regular fibrous eutectics [1][2][3][4][5][6] -the fact that enables its crystallisation in the form of an oriented structure. An attempt to produce oriented structure in the eutectic Fe-C-V alloys has been taken in [1,2].…”

Corrosion Resistance of High-Alloyed White Cast Iron

“…Extensive research published in [5,6] has completed the current state of knowledge about the microstructure and mechanical as well as tribological properties of these alloys.…”