Proceedings of SerbiaTrib '13

Table 1: Chemical composition of sample specimens№ Chemicalelement, %Specimen’s number0 1 2 3 41 C 3,87 3,87 3,87 3,87 3,872 Sn - 0,018 0,020 0,032 0,0513 Si 1,55 1,55 1,55 1,55 1,554 Mn 0,34 0,34 0,34 0,34 0,345 P 0,029 0,068 0,063 0,075 0,0776 S 0,012 0,051 0,059 0,047 0,0607 Cr 0,030 0,030 0,030 0,030 0,0308 Mo 0,018 0,019 0,020 0,017 0,0189 Ni 0,024 0,024 0,024 0,024 0,02410 Co 0,013 0,017 0,014 0,013 0,01311 Cu 0,051 0,058 0,077 0,059 0,07012 Ti 0,0013 0,0013 0,0018 0,0015 0,001313 W 0,126 0,126 0,135 0,123 0,12614 Pb 0,039 0,039 0,043 0,040 0,03915 As 0,036 0,036 0,037 0,038 0,04016 Zr 0,003 0,003 0,003 0,003 0,00317 B 0,0083 0,0083 0,0074 0,0091 0,0088Table 2: Specimens’ hardnessSpecimen’s No. 0 1 2 3 4Sn, % - 0,018 0,020 0,032 0,051Hardness, НВ 179 197 203 262 2772.2 Procedure and device for abrasive wearstudyThe experimental study was realized by aprocedure and device for quick tests according tothe kinematical scheme „pin-on-disk”. Figure 1shows the functional scheme of the device. Theprocedure was elaborated in the Laboratory ofTribology at the Faculty of Industrial Technologyof the Technical University – Sofia. The actuallyvalid standards were taken into consideration [5,6].The studied cylindrical specimen 3 (the body)was mounted fixed in an appropriate holder of theloading head 6. Its position allows that the frontalsurface К enters in contact with the abrasive surface2 of the horizontal disk 1 (the counter-body). Thehorizontal disk 1 is rotating with constant rotationalspeed ω = const around its vertical axis. Thenumber of revolutions of the disk 1 is read by therevolution-counter 5.The device allows variation of the relativesliding speed between the specimen 3 and the disk1 using two manners: by changing the rotationalspeed of the disk through a control unit or byvariation of the distance R between the revolutionaxis of the counter-body 1 and the axis of thespecimen 3.Figure 1: Functional scheme of the device “pin-on-disk”The abrasive surface 2 of the counter-body 1 isbeing modeled through surfaces of impregnatedcarbo-corundum with hardness minimum 60%higher than the hardness of the tested coatingsaccording to the requirements of the standard.The procedure of the investigation comprises thefollowing sequence:1. The surfaces of all specimens, which are of equalcylindrical shape and size, are subjected tomechanical treatment in three stages – rough,grinding and polishing, up to obtaining the equalroughness Ra = 0 ,4 ÷ 0, 6 µ m .13 th International Conference on Tribology – Serbiatrib’13 27