Effect of technological factors on chemical purity of big forging ingots

The effect is characterized of technological factors on the chemical purity of ingots from the CrMoV and CrNiMoV type steels. 85 to 135 t ingots from the CrMoV type steel and 200 t ingots from the CrNiMoV type steels were produced using the method of casting steel from an open-hearth and an electric arc furnaces into a ladle and vacuum casting it into a mould. Analyses and statistical evaluation showed that 1) the technology employed allowed securing the required ingot purity, 2) the ingot weight in the range studied and the site of sampling did not affect the final chemical composition, 3) although the prescribed amount of C and S in the melt was observed, their contents in the ingot could not be safeguarded. (Ha)