The present paper is a presentation of results of a study on morphology, chemical composition, material properties (HVIT, HIT, EIT), and nanoindentation elastic and plastic work for carbide precipitates in chromium cast iron containing 24% Cr. It has been found that the carbides differ in chemical composition, as well as in morphology and values characterizing their material properties. The carbides containing the most chromium which had the shape of thick and long needles were characterized with highest values of the analyzed material properties.

The paper analyses the as-cast state structure of chromium cast iron designed for operation under harsh impact-abrasive conditions. In the process of chromium iron castings manufacture, very strong influence on the structure of this material have the parameters of the technological process. Among others, adding to the Fe-Cr-C alloy the alloying elements like tungsten and titanium leads to the formation of additional carbides in the structure of this cast iron, which may favourably affect the casting properties, including the resistance to abrasive wear.

The present investigation focuses on the study of the influence of titanium inoculation on tribological properties of High Chromium Cast Iron. Studies of tribological properties of High Chromium Cast Iron, in particularly the wear resistance are important because of the special application of this material. High Chromium Cast Iron is widely used for parts that require high wear resistance for example the slurry pumps, brick dies, several pieces of mine drilling equipment, rock machining equipment, and similar ones. Presented research described the effects of various amounts of Fe-Ti as an inoculant for wear resistance. The results of wear resistance were collated with microstructural analysis. The melts were conducted in industrial conditions. The inoculation was carried out on the stream of liquid metal. The following amount of inoculants have been used; 0.17% Fe-Ti, 0.33% Fe-Ti and 0.66% Fe-Ti. The tests were performed on the machine type MAN. The assessment of wear resistance was made on the basis of the weight loss. The experimental results indicate that inoculation improve the wear resistance. In every sample after inoculation the wear resistance was at least 20% higher than the reference sample. The best result, thus the smallest wear loss was achieved for inoculation by 0.66% Fe-Ti. There is the correlation between the changing in microstructure and wear resistance. With greater amount of titanium the microstructure is finer. More fine carbides do not crumbling so quickly from the matrix, improving the wear resistance.

The present work, presented the study of effect of different inoculants on impact toughness in High Chromium Cast Iron. The molds were

pouring in industrial conditions and samples were tested in laboratory in Faculty of Foundry Engineering at AGH. Seven samples were tested

- one reference sample, three with different addition of Fe-Ti, and three with different addition of Al. The samples were subjected to impact

toughness on Charpy hammer and the hardness test. The presented investigations indicate that for the each inoculant there is an optimal

addition at which the sample obtained the highest value of impact toughness. For the Fe-Ti it is 0.66% and for Al is 0.17%. Of all the

examined inoculants best results were obtained at a dose of 0.66% Fe-Ti. Titanium is a well-known as a good modifier but very interesting

results gives the aluminum. Comparing the results obtained for the Fe-Ti and Al can be seen that in the case of aluminum hardness is more

stable. The hardness of all samples is around 40-45 HRC, which is not high for this type of cast iron. Therefore, in future studies it is

planned to carry out the heat treatment procedure that may improves hardness.

The article presents results of heat treatment on the high chromium cast iron. The study was carrying out on samples cut from the casting

made from chromium cast iron. Those were hardened at different temperatures, then tempered and soft annealed. The heat treatment was

performed in a laboratory chamber furnace in the Department of Engineering Alloys and Composites at Faculty of Foundry Engineering

AGH. At each stage of the heat treatment the hardness was measured by Vickers and Rockwell methods, and the microscope images were

done. Additionally based on images from the optical microscope the microstructure was assessed. Based on these results, the effect of

hardening, tempering and soft annealing on the microstructure and hardness of high chromium cast iron was studied. Next the effects of

different hardening temperatures on the properties of high chromium cast iron were compared. The study led to systemize the literature

data of the parameters of heat treatment of high chromium cast iron, and optimal conditions for heat treatment was proposed for casts of

similar properties and parameters.

The paper presents results of Ti-addition to High Chromium Cast Iron (HCCI) on the structure and selected mechanical properties. For this

study casted two sets of cylinders with dimensions ø20 mm, ø15 mm x 250 mm, for the High Chromium Cast Iron (HCCI) and with the

4% by mass Ti-addition. Melts were performed in the induction furnace crucible capacity of 15 kg. During the heats the cup with installed

S type thermocouple was poured to record the cooling curves. The cylinders were subjected to the static bending strength test. Samples for

the test microstructure and Rockwell hardness were cut from the cylinders. The study shows that the addition of titanium had an impact on

the structure and thus the properties of High Chromium Cast Iron (HCCI). In subsequent studies, through an appropriate choice of

chemical composition and proper process control, it is planned to obtain in the structure the titanium carbides TiC and chromium carbides

with type (Cr, Fe)7C3.

Paper presents the results of studies on primary crystallization and wear resistance of high chromium cast iron inoculated with

ferrotitanium intended for work in abrasive conditions. Primary crystallization was examined with use of TDA method, wear tests of the

samples were conducted using the modified pin-on-disk method.

The paper presents results of the possibility of adapting the Althoff-Radtke test for High Chromium Cast Iron. The Althoff-Radtke test is a

clump attempt used for steel. The Althoff-Radtke test has four different lengths of clamp which qualifies it as a test to quantitatively take

into account different kinds of shrinkage ΔL. The length of the slot of the cracked corner and the length of each staple (50 - 350 mm) are

the parameters tendency to cast cracks. Castings of white cast iron have a high tendency to hot cracking due to the large range of

solidification temperatures, unfavorable kinetics parameters of shrinkage, and especially a lack of expansion before shrinkage. Shrinkage

of high chromium white cast iron is similar to the shrinkage of cast steel, and is approximately 2%. Therefore it is important to test

susceptibility to hot cracks. Research was carried out under industrial conditions. Four melts were performed, one of the initial chemical

composition and the other three modified by different amounts of Fe-Ti, respectively, 0.25%, 0.5% and 0.75% Fe-Ti. The propensity for

hot cracking was based on the observation of the dark surface in the corner of the sample. The study shows that the Althoff-Radtke test can

be adapted to determine the tendency for hot cracking of high chromium cast iron. It should however be noted that the test results cannot be

compared with those for other alloys.

The results of research on stereological parameters of carbides in modified hypoeutectic chromium cast iron were shown in the paper. The

effect of distance the casting heat centre of casting to the carbide phase morphology was examined. The samples for metallographic

examination were taken from various locations of the model casting prepared in a special tester. This model casting was designed to

simulate the solidification of heavy castings. Using the proposed methodology the relation of the distance from the model mould and the

size, perimeter, length, width and the shape factor of carbides was examined. During the analysis, the values of stereological parameters of

carbides changed on various sections of the model casting.

High-chromium cast irons are used as abrasion resistant materials. Their wear resistance depends on quantity of carbides and the matrix

supporting these carbides. The paper presents the results of cast irons of chemical composition (in wt. %) 19–22 Cr and 2–4.5 C alloyed by

1.7 Mo + 5 Ni + 2 Mn to improve their toughness, which were tested in working conditions of ferroalloys crushing. Tests showed that

these as-cast chromium cast irons with mostly austenitic matrix achieved the hardness of 38-45 HRC, but their relative abrasion resistance

Ψ ranged from 1.3 to 4.6, was higher comparing to the tool made from the X210Cr12 steel heat treated on hardness 61 HRC. The

transformation of austenite into martensite occurs not only at the worn strained areas (on a surface of scratch) but also in their

neighbourhood. Due to the work hardening of relatively large volumes of transformed austenite the cast iron possesses high abrasion

resistance also on the surfaces where low pressures are acting. The tough abrasion-resistant cast iron well proved for production of

dynamic and wear stressed castings e.g., crusher hammers, cutting tools for ceramic etc.