| 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/mm2, tensile strength increased from 318 to 496 N/mm2, 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 Rp02/Rp02 than conventional ferritic, ferritic-pearlitic and pearlitic compacted graphite iron grades. |
