Can anyone have any idea about this type of defect observed in TMT made from semi killed steel? The steel chemistry is: - C:-0.23%, Mn:-1.2%, S+P < 0.075%, Si-0.05%. What is the reason of origin of this type of solid core in TMTs?
The SEM EDS analysis of the core material is 78% Fe, 18% Oxyegn and 2% Mn.
Figure attached for reference.