Electric heating – Inductive heating – Metal working
Patent
1992-04-02
1995-03-07
Leung, Philip H.
Electric heating
Inductive heating
Metal working
219617, 219654, 219659, H05G 610
Patent
active
053960505
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a method of joining steel sheet bars (sheet bar, slab, billet, bloom and the like) and a joining apparatus which are particularly usable for a case that a preceding transferred sheet bar and a succeeding transferred sheet bar are butt joined at an entrance side of a hot rolling mill and the thus joined sheet bar is continuously fed into a rolling line.
BACKGROUND ART
In the conventional hot rolling line, the sheet bar to be rolled is heated to a target temperature and then fed into rough rolling step and a finish rolling step every the bar to obtain a hot rolled sheet having a desired thickness. In such a rolling system, it is apt to cause troubles such as line stopping due to poor biting of a rolling material in the finish rolling and the like, and also the lowering of yield resulted from poor shapes of front and back end portions of the rolling material is large. Therefore, it is desired to prematurely solve these problems.
As an attempt for solving the above troubles and more improving the productivity in the hot rolling line, there is proposed a rolling technique as disclosed in Japanese Patent laid open No. 60-244401 or Japanese Patent laid open No. 61-159285.
In the technique disclosed in the above publications, the back end of the preceding rolling material and the front end of the succeeding rolling material are joined at the entrance side of the finish rolling step, whereby the several to several ten rolling materials are continuously fed into the finish rolling step. According to such a rolling manner, there is caused no poor biting as generated in case of feeding the sheet bars into the rolling line every the bar and the productivity is largely improved.
However, when a high frequency heating is carried out at portions of the sheet bars to be joined as disclosed in Japanese Patent laid open No. 60-244401, the heating up to a target joining temperature can be attained in a relatively short time, but an extra region other than the region to be joined in the sheet bar is also heated, so that an energy consumption amount used therefor becomes too large. On the otherhand, when electric heating is used as disclosed in Japanese Patent laid open No. 61-159285, if a scale is adhered to the surface of the sheet bar, arc may be generated by contact electric resistance between the sheet bar and electrode roll to damage the electrode roll. In any case, these techniques are insufficient for realizing the continuous hot rolling of the sheet bar.
As to the joining apparatus of the sheet bars, the formation of large-size apparatus is not avoided in the conventional technique, so that it is difficult to apply such an apparatus to the existing line, and also the structure itself becomes complicated, which is poor in its maintenance.
It is an object of the invention to provide a novel joining method capable of simply, rapidly and surely joining sheet bars without wastefully consuming energy and without causing breakage of joint portion between sheet bars in rolling as well as an apparatus directly used for carrying out this method.
DISCLOSURE OF INVENTION
According to the invention, there is the provision of a method of joining sheet bars in hot rolling by butt joining a back end portion of a preceding transferred sheet bar and a front end portion of a succeeding transferred sheet bar at an entrance side of a hot rolling mill, characterized in that the sheet bars are closed to each other by a combination of a treatment that the front end portion and the back end portion of these sheet bars are contacted and heated at such a contact region by applying alternating magnetic fields so as to pass in a thickness direction of the sheet bar with a treatment of pushing at least one of these sheet bars.
In FIG. 1 is shown an embodiment of a rolling apparatus suitable for carrying out the invention, wherein numeral 1 is a hot finish rolling mill, numeral 2 a preceding transferred sheet bar at an entrance side of the hot rolling mill 1 (hereinafter referred to as a preceding she
REFERENCES:
patent: 1903359 (1933-04-01), Sessions
patent: 3366768 (1968-01-01), Osborn, Jr.
patent: 4300031 (1981-11-01), Rgboux et al.
patent: 4706871 (1987-11-01), Kajiwara et al.
patent: 4717801 (1988-01-01), Brolin et al.
Patent Abstracts of Japan, vol. 6, No. 178 (M-155)(1056), 11 Sep. 1982.
Patent Abstracts of Japan, vol. 10, No. 365 (M-524), 6 Dec. 1986.
Amagasa Toshiaki
Aoki Fujio
Ebihara Masanori
Hatano Naoki
Nitta Junzo
Kawasaki Steel Corporation
Leung Philip H.
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