The Effect of Chromium Additions on the Microstructure and Some Mechanical Properties of Delta Steel Company Nodular Cast Iron

Abstract: The effects of chromium additions on the microstructure and some mechanical properties of nodular cast iron have been determined. The nodular cast iron samples containing from 0.6% to 2.6% chromium were produced at Delta steel company. The mechanical properties studied include: Tensile strength, hardness and percentage elongation. The results indicate that the tensile strength and hardness of the samples increased with percentage chromium additions from 449N/𝑚𝑚2 at 0% chromium to 544N/𝑚𝑚2 at 2.6% chromium and from 195BHN at 0% chromium to 323 BHN at 2.6% chromium. However, the percentage elongation of the nodular cast iron sample decreased with increasing percentage chromium additions from 9% at 0% 𝑐ℎ𝑟omium to 2%chromium additions. The microstructure revealed an increase in degree of pearlite phase together with some precipitates of Chromium carbide phase as the chromium level increased.

Keywords: Chromium, Nodular Cast Iron, Ferrous Metals.