Hyundai Steel Company

Jutae Choi

Sukhyun Yoo

Kaeyoung Lee

Wonjae Cho

Kyoungho So

Jinsoo Jang

Hyojoong Kwon

Hongkil Moon

Jaehwan Ahn

A method for evaluating center segregation of a continuous cast slab is provided. The method of the present invention includes (A) creating a center segregation image of a slab using an etching solution comprising a picric acid (CHNO), a cupric chloride (CuCl), sodium laurylbenzenesulfonate (CHSONa) and the remainder of distilled water; and (B) evaluating the center segregation of a slab by scanning the image and applying the following Formula. The method creates an image of center segregation even for low-carbon steel having carbon (C) in an amount of 0.04 wt % or less as well as ultra low-sulfur steel having sulfur (S) in an amount of 50 ppm or less.

Method of evaluating center segregation of continuous cast slab

The present invention relates to a mold powder supply apparatus using the waste heat of a tundish, which can collect waste heat from molten steel in the tundish, and preheat and dry mold powder. The mold powder supply apparatus using the waste heat of a tundish according to an embodiment of the present invention includes: a powder hopper that is mounted to a frame close to a tundish to absorb heat radiated from the top of the tundish, through one side; an agitator that agitates mold powder filled in the powder hopper; and a supply pipe that is connected to the bottom of the powder hopper to supply the powder hopper into a mold.

Mold powder supply apparatus using the waste heat of a tundish

Disclosed is a method of predicting surface quality of a thin slab hot rolled coil. The method includes calculating the Cu equivalent (Cu eq.) of molten steel, applying the calculated Cu equivalent of the molten steel into an equation: 120&#xd7;(Cu equivalent)&#x2212;6&#xd7;(Cu equivalent) to calculate a surface crack index, and predicting the generation of surface defect of the thin slab hot rolled coil by the surface crack index. A method of producing the thin slab hot rolled coil using the same is also provided. The surface crack defect of the thin slab hot rolled coil can be predicted by calculating the Cu equivalent of the molten steel, and thus a thin slab which meets the quality standard demanded by a consumer can be provided, and this results in increased productivity and product reliability.

Method for predicting surface quality of thin slab hot rolled coil and method for producing thin slab hot rolled coil using the same

The present invention relates to an apparatus for centering a submerged entry nozzle. The present invention includes: a plurality of laser beam generatorsthat is disposed above a moldfor continuous casting to radiate a laser beam toward the center of the mold; a tundish moving unitthat moves a tundishabove the mold; and a control unit that is linked with the laser beam generatorsand controls the tundish moving unitto center the installation position of the submerged entry nozzleprovided at the lower portion of the tundish, in response to signals transmitted from the laser beam generators. According to the present invention, in addition to accurately and quickly centering the submerged entry nozzle, it is possible to maintain the submerged entry nozzle that has been centered, such that it is possible to minimize a channeling phenomenon of molten steel. Accordingly, it can be expected to improve the quality of a slab.

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Seoul, South Korea

Jutae Choi