The cast alloys crystallizing in Fe-C-V system are classified as white cast iron, because all the carbon is bound in vanadium carbides. High
vanadium cast iron has a very high abrasion resistance due to hard VC vanadium carbides. However, as opposed to ordinary white cast
iron, this material can be treated using conventional machining tools. This article contains the results of the group of Fe-C-V alloys of
various microstructure which are been tested metallographic, mechanical using an INSTRON machine and machinability with the method
of drilling. The study shows that controlling the proper chemical composition can influence on the type and shape of the crystallized
matrix and vanadium carbides. This makes it possible to obtain a high-vanadium cast iron with very high wear resistance while
maintaining a good workability.
This paper presents the results of studies of high-alloyed white cast iron modified with lanthanum, titanium, and aluminium-strontium. The
samples were taken from four melts of high-vanadium cast iron with constant carbon and vanadium content and near-eutectic
microstructure into which the tested inoculants were introduced in an amount of 1 wt% respective of the charge weight. The study
included a metallographic examinations, mechanical testing, as well as hardness and impact resistance measurements taken on the obtained
alloys. Studies have shown that different additives affect both the microstructure and mechanical properties of high-vanadium cast iron.
The paper presents the results of abrasive wear resistance tests carried out on high-vanadium cast iron with spheroidal VC carbides. The cast iron of eutectic composition was subjected to spheroidising treatment using magnesium master alloy. The tribological properties were examined for the base cast iron (W), for the cast iron subjected to spheroidising treatment (S) and for the abrasion-resistant steel (SH). Studies have shown that high-vanadium cast iron with both eutectic carbides and spheroidal carbides has the abrasion resistance twice as high as the abrasion-resistant cast steel. The spheroidisation of VC carbides did not change the abrasion resistance compared to the base high-vanadium grade.
The paper presents the results of tests on the spheroidising treatment of vanadium carbides VC done with magnesium master alloy and mischmetal. It has been proved that the introduction of magnesium master alloy to an Fe-C-V system of eutectic composition made 34% of carbides crystallise in the form of spheroids. Adding mischmetal to the base alloy melt caused 28% of the vanadium carbides crystallise as dendrites. In base alloy without the microstructure-modifying additives, vanadium carbides crystallised in the form of a branched fibrous eutectic skeleton. Testing of mechanical properties has proved that the spheroidising treatment of VC carbides in high-vanadium cast iron increases the tensile strength by about 60% and elongation 14 - 21 times, depending on the type of the spheroidising agent used. Tribological studies have shown that high-vanadium cast iron with eutectic, dendritic and spheroidal carbides has the abrasive wear resistance more than twice as high as the abrasion-resistant cast steel.