PURPOSE: To obtain inexpensively a thick steel plate having strength and toughness as well as excellent weldability by using a low C alloy steel without passing the same through a temper rolling stage by using two units of rolling mills disposed on the same rolling line as a tandem reverse mill.
CONSTITUTION: Two units of rolling mills 2, 3 are disposed apart from each other at a relatively short space on a series of a rolling line 6. The slab is heated to about 920°C right above the Ac3 point to form fine austenite grains. The hot slab ejected from a heating furnace 1 arrives at the mill 2 at about 900°C where the slab is rolled back and forth in several strokes (a) so as to be subjected to cross rolling as well. Then the thickness is decreased and the rolled material passes continuously the mills 2, 3 from the point of the time when the length increases to some extent, then the material passes continuously both rolling mills in the next pass. Such tandem reverse rolling of the two stands is performed in several strokes (b). The material completed of the rolling arrives at a cooler 5 through a setting machine 4. The temp. of the steel plate on the inlet side of the device 5 is assured at about 780°C above the A3 point, whereby the fine crystal grains are formed.
UEHORI YUUJI
ONOUE YASUMITSU
MATSUMURA SHIGEHIKO
| JPS5496455A | 1979-07-30 | |||
| JP45019376A |
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