Nippon Steel Corporation

Mitsubishi Jukogyo Kabushiki Kaisha

Shigenori Tanaka

Satoshi Akamatsu

Mitsuo Uchimura

Shigeru Ogawa

Masafumi Miyazaki

Akinobu Murasato

Takashi Sawai

Yasuharu Sakuma

Hideki Oka

Hiroyuki Nakashima

Kunimasa Sasaki

Yoshikazu Matsumura

Hidemaro Takeuchi

Masahiro Doki

Takashi Furuya

Isao Suichi

Junji Nakashima

Hiroyuki Kajioka

Yoshimori Fukuda

Toyoichiro Higashi

Jun Fukuda

Hiroshi Ohba

Atsumu Yamane

A billet produced by continuous casting having little central segregation, in particular a billet of high carbon steel produced by continuous casting, and a manufacturing method therefor are provided. In the continuous casting billet, the size of the dendritic equiaxed crystal in a billet central portion is reduced to be not more than 6 mm. For this purpose, electromagnetic stirring is performed so that the inclining angle of the primary dendrite within 10 mm of a billet surface layer is increased to be not less than 10&#xb0;. Furthermore, the mechanical soft reduction is performed during continuous casting so that the diameter of the center porosity in the billet central portion is reduced to be not more than 4 mm. Thereby, in particular in the manufacturing of the continuous casting billet having a carbon content of not less than 0.6% by mass and a billet size of not more than 160 mm can be provided a billet in which breaking troubles in wire drawing after rolling to a rod are reduced by reducing the central segregation in the billet.

Billet by continuous casting and manufacturing method for the same

The present invention provides a steel for steel sheets excellent in workability and showing significantly decreased formation of surface defects, and a method of deoxidizing molten steel for the steel for steel sheets which prevents nozzle clogging during continuous-casting the molten steel. That is, the steel for steel sheets excellent in workability, comprises, based on weight, 0.0001 to 0.0030% of C, up to 0.03% of Si, 0.05 to 0.30% of Mn, up to 0.015% of P, 0.001 to 0.015% of S, up to 0.008% of Al, 0.02 to 0.08% of Ti, 0.0005 to 0.0020% of Ca, 0.0005 to 0.01% of N, optionally containing at least one of 0.001 to 0.02 wt % of Nb and 0.0001 to 0.0010 wt % of B, and the balance of Fe and unavoidable impurities. Moreover, the deoxidation method of the steel for steel sheets comprises properly adjusting addition amounts of Ca and Al as deoxidizing agents for the steel having the chemical composition mentioned above so that the chemical composition of the nonmetallic inclusions is controlled to prevent clogging of the casting nozzle.

Steel for steel excellent in workability and method of deoxidizing same

Process for continuously casting sheet metal and apparatus for

Process for producing thin cast strip

Thin continuous cast plate and process for manufacturing the same

A control device for a twin-roll continuous caster, comprising a plurality of maps, each of which teaches a relationship between a thickness of a cast strip and a roll separating force under a fixed casting speed, and teaches stable casting conditions under which bulging and surface cracks do not occur. The device detects a cast thickness and a height of the molten pool and selects an appropriate map from among the plurality of maps, by the detected height, and controls the casting conditions such that a target thickness of the cast strip is obtained under stable casting conditions by using the selected map.

Control device and a control method for twin-roll continuous caster

Growing community of inventors

Hikari, Japan

Shigenori Tanaka