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Estimation of Non‐Metallic Inclusions in Industrial Ni Based Alloys 825
Author(s) -
Kellner Hans E. O.,
Karasev Andrey V.,
Sundqvist Olle,
Memarpour Arashk,
Jönsson Pär G.
Publication year - 2017
Publication title -
steel research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.603
H-Index - 49
eISSN - 1869-344X
pISSN - 1611-3683
DOI - 10.1002/srin.201600024
Subject(s) - alloy , materials science , non metallic inclusions , metallurgy , ladle , inclusion (mineral) , type (biology) , metal , tin , casting , mineralogy , chemistry , geology , paleontology
It is well known that inclusions affect the properties of the steel and other alloys. The importance of understanding the behavior of the inclusions during production can never be overstated. This study has examined the main types of big size (>10 μm) inclusions that exist in Ni‐based Alloy at the end of ladle treatment and after casting during industrial production of Ni based Alloys 825. Sources, mechanisms of formation and behavior of different type large size inclusions in Alloy 825 are discussed based on 2 and 3D investigations of inclusion characteristics (such as, morphology, composition, size, and number) and thermodynamic considerations. The large size inclusions found can be divided in spherical (Type I and II) inclusions and in clusters (Type III–V). Type I‐A inclusions (Al 2 O 3 –CaO–MgO) originate from the slag. Type I‐B inclusions and Type II inclusions consist of CaO–Al 2 O 3 –MgO and Al 2 O 3 –TiO 2 –CaO, respectively. Both types originate from the FeTi70R alloy. Type III clusters (Al 2 O 3 –MgO–CaO) are formed during an Al deoxidation of the Ni‐based alloy. Type IV clusters (Al 2 O 3 –TiO 2 –CaO) formed from small inclusions, which are precipitated in local zones which contain high Ti and Al levels. These clusters are transformed to Type III clusters over time in the ladle. Finally, Type V clusters are typical TiN clusters.