Evolution of Tantalum Content During Vacuum Induction Melting and Electroslag Remelting of a Novel Martensitic Steel

Journal Article · 31 May 2019 · Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science

DOI: https://doi.org/10.1007/s11663-019-01614-z · OSTI ID:1582384

Detrois, Martin ^[1]; Jablonski, Paul D. ^[2]; Hawk, Jeffrey A. ^[2]

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1. National Energy Technology Lab. (NETL), Albany, OR (United States); Leidos Research Support Team, Pittsburgh, PA (United States)
2. National Energy Technology Lab. (NETL), Albany, OR (United States)

The need for materials with superior thermal and mechanical properties while mitigating cost increases interest in new complex alloy compositions which brings challenges to manufacturing processes. In this investigation, vacuum induction melting (VIM) and electroslag remelting (ESR) of a novel tantalum (Ta)-containing martensitic steel was performed using standard industry practices at a laboratory scale. A 25 pct loss of Ta was measured from the VIM electrode to the ESR ingot using X-ray fluorescence. Several tools were used for broad characterization of the ingots, including LECO for chemistry analysis, scanning electron microscopy, and electron probe microanalysis for observation of the precipitate and inclusion phases post-VIM and post-ESR as well as computational modeling of the ESR process for the calculation of macrosegregation and inclusion travel. Here, it was found that a significant amount of Ta₂O₅ inclusions formed during VIM and were transferred to the slag during ESR. While ESR was particularly successful at decreasing the number density of inclusions by 95 pct, additional efforts are needed with regard to vacuum leak rate and purity of stock material when melting novel advanced steels.

• Research Organization: National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States)
• Sponsoring Organization: USDOE Office of Fossil Energy (FE)
• OSTI ID: 1582384
• Report Number(s): NA
• Journal Information: Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science, Vol. 50, Issue 4; ISSN 1073-5615
• Publisher: ASM InternationalCopyright Statement
• Country of Publication: United States
• Language: English