Finish rolling method for production of round cross-sectional shape materials
AssigneeNippon Steel Corporation
InventorsMichio Nishikubo, Sei Miura, Toshiaki Toyoda, Katsunori Jonishi, Kouichi Yoneta
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Abstract
In the rolling of metal material to round cross-sectional shape through a succession of three roll stands with the horizontal-horizontal-vertical, or vertical-vertical-horizontal rolls arranged in this order in the rolling down direction for achievement of increased accuracy of dimensional control at finish, an initial metal stock of specific oval cross-section is rolled to an intermediate and small reduction through the first and second stands forming specific oval groove, and then to a finish and small reduction through the third stand forming a round groove.
Claims1
A finish rolling method of metal products of round sectional shape comprising:
- a. Introducing a starting material of oval cross-sectional shape into a finish rolling train comprising at least a first, a second and a third stand arranged close to each other in the stated order from an inlet side of the train;
- b. rolling the starting material into an oval cross-sectional shape with a light reduction from the same direction in the first and second stands;
- and
- c. finish rolling in the third stand the thus light reduced oval material into a round cross-sectional shape with a light reduction in a direction almost perpendicular to the reduction direction in the first and second stands,
- wherein the starting material has a cross-sectional dimension as below:
- 1. when a final product of 5 to not more than 40 mm diameter is to be obtained;
- then the
- Major diameter = (1.07D + 0.5)mm .about. (1.18D + 0.4)mm and the
- Minor diameter = (1.01D + 0.2)mm .about. (1.05D + 0.4)mm, and
- 2. when a final product of 40 to not more than 200 mm diameter is to be obtained;
- then the
- Major diameter = (1.04D + 1.5)mm .about. (1.10D + 3.5)mm and the
- Minor diameter = (1.01D + 0.2)mm .about. (1.02D + 1.5)mm
- and wherein the starting material which has been rolled in the first and second stands has a cross-sectional dimension as below:
- 1. when a final product of 5 to not more than 40 mm diameter is to be obtained;
- then the
- Major diameter = (1.0712D + 0.52)mm .about. (1.1865D + 0.45)mm and the
- Minor diameter = (0.985D - 0.1)mm .about. 0.998Dmm, and
- 2. when a final product of 40 to not more than 200 mm diameter is to be obtained;
- then the
- Major diameter = (1.0412D + 1.52)mm .about. (1.1035D + 3.65)mm and the
- Minor diameter = 0.985Dmm .about. 0.998Dmm,
- the distance of the roll center of the first stand and that of the second stand being not longer than (5.6D + 400)mm and the distance between the roll center of the second stand and that of the third stand being not longer than (4.6D + 320)mm and wherein the rolling groove of the first and second stands has a cross-sectional dimension as below:
- 1. when a final product of 5 to not more than 40 mm diameter is to be obtained;
- then the
- Major diameter = (1.1412D + 2.02)mm .about. (1.2565D + 1.95) mm, the
- Minor diameter = (0.985D - 0.1)mm .about. 0.998Dmm, and
- 2. when a final product of 40 to not more than 200 mm diameter is to be obtained;
- then the
- Major diameter = (1.0912D + 4.02)mm .about. (1.1535D + 6.15)mm, the
- Minor diameter = 0.985D .about. 0.998Dmm
- in which D is the distance between two points at which a straight line perpendicular to the roll gap center line and passing through a central point of the third stand groove intersects the upper and lower roll profile curves in the third stand.
Dependencies are inferred from the claim text.