| Sažetak (engleski) | The microstructure, tensile properties and hardness of 25 mm thick compacted graphite iron samples alloyed with 3,01, 3,22, 3,61, 3,97 and 4,29 wt. % Si were analyzed in this paper. It was found that Si promotes and strengthens ferrite. Metallic matrix of compacted graphite iron sample alloyed with 3,01 wt. % Si consisted of 98,1 % ferrite and 1,9 % pearlite. Fully ferritic metallic matrix was obtained in compacted graphite iron samples alloyed with 3,22, 3,61, 3,97 and 4,29 wt. % Si. Nodularity varied from 8 to 13 %. Yield strength increased from 246 to 447 N/mm<sup>2</sup>, tensile strength increased from 318 to 496 N/mm<sup>2</sup>, hardness increased from 160 to 227 HBW, and elongation decreased from 3,6 to 1,6 % with an increase in Si content from 3,01 to 4,29 wt. %. Analyzed Si alloyed compacted graphite iron samples have a very uniform hardness and higher ratio R<sub>p02</sub>/R<sub>p02</sub> than conventional ferritic, ferritic-pearlitic and pearlitic compacted graphite iron grades. |
