Mitsubishi Heavy Industries Limited

Junso Fukumori

Tsutomu Kawamizu

Akira Kaya

Kyung Zoon Min

Woon Yong Choi

Sung Doo Kim

Jong Won Lee

An apparatus and a method for suppressing growth of an oxide film on a coil which is a spirally wound, rolled strip are disclosed. A rolled strip subjected to rolling by hot rolling equipment is wound spirally by a down-coiler to make a coil. Covers are disposed on the opposite sides of the coil such that heat resistant materials intimately contact the opposite sides of the coil. The covers are fixed by L-bolts and nuts to cover the opposite sides of the coil with the covers. In this state, the coil is naturally cooled for a predetermined time to suppress growth of an oxide film and increase productivity.

Apparatus and method for suppressing growth of oxide film on coil

A system and a method are disclosed for preventing scale defects during hot rolling by hot rolling equipment having a scale breaker provided at an entry side of a finishing mill line composed of a plurality of rolling mills arranged in tandem. A descaler is provided between a first stage rolling mill and a second stage rolling mill of the finishing mill line. A cooler for cooling a hot rolled steel plate is provided between the second stage rolling mill and a third stage rolling mill of the finishing mill line. A control device is provided for controlling the descaler and the cooler to be selectively driven such that neither of the descaler and the cooler is actuated, one of the descaler and the cooler is actuated, or both of the descaler and the cooler are actuated, according to rolling conditions. Thus, the hot rolled steel plate is rolled, with its oxide film thickness at an entry side of the third stage rolling mill being restricted to not more than a limiting oxide film thickness of 5 &mgr;m. Consequently, scale defects are prevented, and overcooling of the hot rolled steel plate is suppressed, to improve the quality of a product.

System and method for preventing scale defects during hot rolling

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Hiroshima, Japan

Junso Fukumori