Effect of Current Intensity on the Cleanliness of Electroslag Ingots During Low Frequency Electroslag Remelting

Abstract

Based on the laboratory small-scale low-frequency electroslag remelting device， taking 70%CaF2+30%Al2O3 electroslag remelting 304L austenitic stainless steel as the research object， we analyze in detail the influence of different remelting current intensity on the number， size dimension and type of inclusions in the electroslag ingot under low-frequency conditions. The results show that compared with the power frequency electroslag remelting （50 Hz， 1 800 A）， the oxygen （O） content in electroslag ingot increased by 172.2% and 75.5% respectively under the condition of low frequency （2 Hz） and different current intensities （1 800 and 1 400 A）. Nitrogen （N） content decreased by 4% and 3.4%， respectively.At low frequency， the type of inclusions in the electroslag ingot did not change when remelted with different current intensities， but the number of inclusions and the proportion of each type of inclusions changed. The number of inclusions decreases with the decrease of current intensity at low frequency， However， compared with the power frequency condition， the amount of debris still increased by 173% （1 800 A） and 63.7% （1 400 A）， and the increase part was basically small inclusions below 10 μm， and the amount of large-size inclusions （>10 μm） increased less.

Keywords

• electroslag remelting； current strength； low frequency； inclusion； cleanliness