PURPOSE: To reform an existing mandrel mill line at low cost and to produce product pipes of larger outside diameters by composing rolling equipment for seamless pipes of a Mannesmann inclined piercer, a mandrel mill, a reheating furnace, a incline type expansion rolling mill and a pipe finishing mill.
CONSTITUTION: A black billet 2 heated in a rotary hearth type heating furnace 1 is pierced by a Mannesmann piercer 3 which is the inclined piercer and is made into a hollow pipe stock 4a. A mandrel bar 5 is hen inserted into this hollow pipe stock 4a and the hollow pipe stock 4a is stretched to a smaller thickness by the mandrel mill 6, by which the hollow pipe stock 4b is obtd. The mandrel bar 5 is drawn out of the inside of the hollow pipe stock 4b and the hollow pipe stock is reheated by the reheating furnace 7. The reheated hollow pipe stock 4c is expansion rolled by the inclined expansion rolling mill 8 and is made into the pipe stock 4d for finish rolling having the outside diameter large than the outside diameter of the hollow pipe stock 4c. The pipe stock 4d for finish rolling is finished to a product 10 of a prescribed outside diameter by the pipe finishing mill 9.
| JP2000288616 | MANUFACTURE OF SEAMLESS STEEL TUBE |
| JPH04168221 | MANUFACTURE OF AUSTENITIC STAINLESS SEAMLESS STEEL TUBE |
YORIFUJI AKIRA
TOYOOKA TAKAAKI
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