2.4. Hardness Test

The study of hardness and deformation level consisted of two separate stages—initially the samples were subjected to Brinell hardness testing (HBW). The goal of this activity was to locally harden the particular steel sample as a consequence of dislocating the grains of the crystal structure. Subsequently, in the very same spot a Rockwell (hardness test (HRC) was performed in order to evaluate the work-hardening ability of the material. This activity was undertaken to simulate the working conditions of the excavating chain. This measurements were afterwards compared to the values of HRC hardness of the untreated steel region. Hardness measurements were made using Zwick/Roell ZHU 187.5 (Zwick Roell Group, Ulm, Germany) hardness tester. The authors consider this method of evaluation of surface hardenability of high-manganese cast steels as a novelty, as it was not mentioned in the found literature.

The tests were carried out using the FM-700 Hardness Tester (InnovaTest, Maastricht, The Netherlands). The measurement points were located every 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 9 and 13 mm from the edge of the peg hole. Each of the samples was subjected to 10 measurements. The total distance from the first to the last measurement point from the eroded contact edge was 13 mm. Hardness was measured using the Vickers method with a load of 4.90 N (HV0.5). The time of measurement was set to 10 s.