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Comparative Study of the Cleanliness of Interstitial‐Free Steel with Low and High Phosphorus Contents
Author(s) -
Li Yihong,
He Yibo,
Ren Zhifeng,
Bao Yanping,
Wang Rui
Publication year - 2021
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.202000581
Subject(s) - tundish , metallurgy , materials science , nozzle , clogging , phosphorus , mold , slag (welding) , liquid steel , continuous casting , composite material , history , physics , archaeology , thermodynamics
Herein, a study comparatively investigating the total oxygen (TO) and nitrogen (N) contents, evolution of inclusions, variations in slag composition, and nozzle clogging during the production of an interstitial‐free (IF) steel and a P‐containing high‐strength (HS) IF steel is presented. The results show that during the production of both steels, the TO content gradually decreases after the deoxidation, with the TO content in the molten steel in the tundish below 30 ppm. There is no significant variance in the N content. The two steels have similar quantities of small inclusions of similar types and sizes. However, the P‐containing HS IF steel has a much higher content of large inclusions, which mainly come from the entrapped mold powder and peeled‐off nozzle clogging. Compared to the common IF steel, the P‐containing HS IF steel has a higher MnO content in the slag during the Ruhrstahl–Heraeus process, compromising cleanliness control; the P‐containing HS IF steel has more significant mold liquid‐level fluctuations and more nozzle clogging, which mainly consists of Al 2 O 3 and TiO 2 . The cause of these issues during the production of the P‐containing HS IF steel is concluded to be related to the high P content.