TITLE:
Electroslag Remelting of High Technological Steels
AUTHORS:
Hossam Halfa, A. M. Reda
KEYWORDS:
Electroslag, Maraging, Cobalt Free, Tool-Steel, Nitrogen, Niobium
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.3 No.6,
November
9,
2015
ABSTRACT: This work aims at the suitability of electroslag process on production of high technological steels
such as Maraging steel, modified high speed tool steel (niobium, high nitrogen, and free nitrogen)
has been investigated. The experimental results show that high recovery of alloying elements
during electroslag remelting of such steels especially high nitrogen tool steel. The previous results
are attributed to the slag used in electroslag protect the molten metal from atmospheric oxygen.
Also higher recovery of alloying elements during remelting high nitrogen high speed tool steel are
due to partial dissolution of nitrides during remelting of such steel which increase nitrogen content
above the molten slag which decrease the partial pressure of oxygen leads to protection of
molten metal from further oxidation. Also, the results show that, produced ingots are free from
internal pipes, porosity and other surface defects. Microstructure obtained for remelted steels is
very fine and well distributed for all steel under investigation. In the case of electroslag remelted
Maraging steels lower non-metallic inclusions with very fine inclusions and redistribution retained
austenite with very fine structure leads to increasing all tensile properties of investigated
steels. In the case of high speed tool steels, also the structure is very fine, well distributed, densely and short carbides with lower non-metallic inclusions contents. High cooling rate accompanying
with electroslag process has a great effect on type, morphology and content of carbides precipitated
in both nitrogen and niobium modified tool steels.