Improved Molten Metal Sampling Method for Hydrogen Content Analysis

The main disadvantage of the existing sampling method of metal for hydrogen content analysis is the contact of metal with air moisture during an open overpour from a metal scoop to the ingot mold. In response, a novel method is proposed for sampling molten aluminum and its alloys for hydrogen content analysis by dipping a conical ingot mold sampler into the melt. The work was performed at the Sayanogorsk aluminum plant UC RUSAL in the technological workflow from a transport ladle to the casting machine. Hydrogen analysis results using the proposed method are compared to those of the sampling method using the Rensley chill mold. The error in the hydrogen content measurement of the sample under the existing sampling scheme with overpour of metal from a metal scoop into the ingot mold was confirmed. The hydrogen concentration in the samples taken in the Rensley chill mold is less, on average, by 0.019 cm 3 /100 g Al, than in the samples obtained using the newly developed ingot mold sampler. Results of the study reveal that the proposed sampling method provides an additional advantage when sampling molten metal.