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1

Influence of Pre-Hardened Gx120mn13 Cast Steel on the Tribological Properties under Technically Dry Friction

Kalandyk Barbara, Zapała Renata, Madej Monika, Kasińska Justyna, Piotrowska Katarzyna

Tribologia

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2022

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nr 3

17--24

EN

This paper presents the results of tribological tests on high manganese GX120Mn13 cast steel under technically dry friction conditions. The tests were carried out using a TRB3 ball-on-disc tribometer using a 6mm-diameter SiC ball as a counter-sample for a specimen made of GX120Mn13 cast steel containing a localised prehardening area on the test surface with a hardness of approximately 597 HV10 (the non-hardened area had a hardness of approximately 325–364 HV10). During the test, the ball travelled in a 16.68 mm diameter circle and passed through both hardening and non-hardened areas. The resulting erosion marks were assessed using an optical profilometer and scanning microscope tests, which showed that the maximum depth of erosion in the previously hardening area was 0.77 µm and was more than twice as deep as in the non-hardened areas surveyed. In contrast, the area of attrition was twice as small as in the non-hardened area located in the axis of the previously applied load and more than three times smaller, but in the area located on the side of the axis and 8.34 mm away from it. Thus, from the point of view of the abrasion resistance of GX120Mn13 cast steel, the validity of its prior hardening before the operation was confirmed.

PL

W artykule przedstawiono wyniki badań tribologicznych wysokomanganowego staliwa GX120Mn13 w warunkach tarcia technicznie suchego. Badania przeprowadzono przy użyciu tribometru TRB3 typu ball–on– disc stosując jako przeciwpróbkę kulkę z SiC o średnicy 6mm dla próbki wykonanej ze staliwa GX120Mn13 zawierającej na powierzchni badanej lokalny obszar wcześniej umocniony o twardości ok. 597 HV10 (obszar nieumocniony posiadał twardość ok 325–364 HV10). Kulka w czasie testu poruszała się po okręgu o średnicy 16.68 mm i przechodziła zarówno przez obszar umocniony, jak i nieumocniony. Otrzymane ślady wytarcia oceniano za pomocą badań wykonanych na profilometrze optycznym i mikroskopie skaningowym. Na podstawie przeprowadzonych badań wykazano, że w obszarze wcześniej umocnionym maksymalna głębokość wytarcia wynosiła 0.77 µm i była ponad dwukrotnie mniejsza niż w badanych obszarach nieumocnionych. Z kolei pole wytarcia było dwukrotnie mniejsze niż w obszarze nieumocnionym, znajdującym się w osi przyłożonego wcześniej obciążenia i ponad trzykrotnie mniejsze w porównaniu z obszarem znajdującym się z boku osi i oddalonym od niej o 8.34 mm. Tym samym, z punktu widzenia odporności na zużycie ścierne staliwa GX120Mn13, potwierdzono słuszność jego wcześniejszego umocnienia przed eksploatacją.

2

Evaluation of Microstructure and Tribological Properties of GX120Mn13 and GX120MnCr18-2 Cast Steels

Kalandyk B., Zapała R., Kasińska J., Madej M.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 4

77--81

EN

The results of microstructure examinations and hardness measurements carried out on two selected grades of high-manganese cast steel with an austenitic matrix, i.e. GX120Mn13 and GX120MnCr18-2, are presented. The examinations of the cast steel microstructure have revealed that the matrix of the GX120MnCr18-2 cast steel contains the precipitates of complex carbides enriched in Cr and Mn with two different morphologies. The presence of these precipitates leads to an increase in hardness by approx. 30 HB compared to the GX120Mn13 cast steel. Samples cut out from the tested materials were loaded (10 strokes) with an energy of 53 J, and then a ball-on-disc tribological test was performed. The test was carried out in reciprocating motion under technically dry friction conditions. While analyzing the obtained results of the microstructure, hardness, and abrasion tests, it was found that the presence of the hard carbide precipitates in the plastic matrix of the tested GX120MnCr18-2 cast steel promoted an increase in hardness, but also led to chipping of these particles from the alloy matrix, thus contributing to micro-cutting during friction.

3

Investigations of protective coatings for castings of high-manganese cast steels

Holtzer M., Bobrowski A., Drożyński D., Mocek J.

Archives of Foundry Engineering

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2013

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Vol. 13, iss. 1

39--44

EN

When cast steel castings are made in moulding sands on matrices of high-silica sand, which has a low fire resistance the problem of the so-called chemical penetration is distinctly visible. Whereas this effect appears to a small degree only when moulding sand matrices are of chromite, zircon or olivine sands. Therefore in case of making castings of high-manganese cast steel (e.g. Hadfield steel) sands not containing free silica should be applied (e.g. olivine sand) or in case of a high-silica matrix protective coatings for moulds and cores should be used. Two protective coatings, magnesite alcoholic (marked as coating 1 and coating 2) originated from different producers and intended for moulds for castings of the Hadfield steel, were selected for investigations. Examinations of the basic properties were performed for these coatings: viscosity, thermal analysis, sedimentation properties, wear resistance. In order to estimate the effectiveness of protective coatings the experimental castings were prepared. When applying coating 1, the surface quality of the casting was worse and traces of interaction between the casting material (cast steel) and the coating were seen. When protective coating 2 was used none interactions were seen and the surface quality was better.

4

The comparative studies of ADI versus Hadfield cast steel wear resistance

Skoczylas P., Krzyńska A., Kaczorowski M.

Archives of Foundry Engineering

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2011

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Vol. 11, iss. 2

123-126

EN

The results of comparative studies of wear resistance of ADI versus high manganese Hadfield cast steel are presented. For evaluation of wear resistance three type of ADI were chosen. Two of them were of moderate strength ADI with 800 and 1000MPa tensile strength while the third was 1400MPa tensile strength ADI. The specimens were cut from ADI test YII type casting poured and heat treated in Institute of Foundry in Krakow. The pin on disc method was used for wear resistance experiment. The specimens had a shape of 40mm long rod with diameter 6mm. The load and speed were 100N and 0,54m/s respectively. It was concluded that the wear resistance of ADI is comparable with high manganese cast steel and in case of low tensile grade ADI and is even better for high strength ADI than Hadfield steel.

5

On the possibility of replacing high manganese cast steel military vehicle track pads with ADI

Kaczorowski M., Skoczylas P., Krzyńska A.

Archives of Foundry Engineering

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2010

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Vol. 10, iss. 1 spec.

81--86

EN

The theoretical considerations of possibility replacing of high manganese cast steel used for military vehicle track pads with ADI are presented. Except these considerations, comparative investigations including tensile strength tests hardness measurements and impact resistance were included. Moreover, the structure investigation was carried out using either conventional light metallography and scanning (SEM). The last one was applied for fractography investigations, the aim of which was to discover the mode of fracture. The discussion of experimental results leads to conclusion that ADI, known as high friction resistant, looks to be concurrent material with respect to high manganese cast steel used now for tang track pads.