Method for producing H-shaped steel

Patent metadata

Field	Value
Publication number	US-10730086-B2
Application number	US-201615559310-A
Country	US
Kind code	B2
Filing date	Mar 10, 2016
Priority date	Mar 19, 2015
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

[Object] To suppress occurrence of shape defects in a material to be rolled and enable efficient and stable production of an H-shaped steel product with a flange width larger than a conventional flange width by creating deep splits on end surfaces of a material (e.g., slab) using projections with acute-angle tip shapes, and sequentially bending formed flange portions.
[Solution] Provided is a method for producing H-shaped steel, the method including: a rough rolling step; an intermediate rolling step; and a finish rolling step. In a rolling mill that performs the rough rolling step, a plurality of calibers to shape a material to be rolled are engraved, the number of the plurality of calibers being four or more. Shaping of one or a plurality of passes is performed on the material to be rolled in the plurality of calibers. In a first caliber and a second caliber among the plurality of calibers, projections to create splits vertically with respect to a width direction of the material to be rolled are formed. In a second caliber and subsequent calibers among the plurality of calibers, reduction is performed in a state where end surfaces of the material to be rolled are in contact with caliber peripheral surfaces in shaping of at least one pass. In a third caliber and subsequent calibers among the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed.

First claim

The invention claimed is:

1. A method for producing H-shaped steel, the method comprising:
a rough rolling step;
an intermediate rolling step; and
a finish rolling step,
wherein in a rolling mill that performs the rough rolling step, a plurality of calibers to shape a material to be rolled are engraved, the number of the plurality of calibers being four or more,
shaping of one or a plurality of passes is performed on the material to be rolled in the plurality of calibers,
in a first caliber and a second caliber among the plurality of calibers, projections to create splits vertically with respect to a width direction of the material to be rolled are formed,
in a second caliber and subsequent calibers among the plurality of calibers, reduction is performed in a state where end surfaces of the material to be rolled are in contact with caliber peripheral surfaces in shaping of at least one pass,
in two or more of a third caliber and subsequent calibers among the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed, and
the projections formed in the first caliber and the second caliber have a tip angle of 40° or less.

2. The method for producing H-shaped steel according to claim 1 , wherein the pass in which reduction is performed in a state where the end surfaces of the material to be rolled are in contact with the caliber peripheral surfaces is a final pass in shaping of a plurality of passes using each of the second caliber and subsequent calibers among the plurality of calibers.

3. The method for producing H-shaped steel according to claim 1 , wherein in the second caliber, inclined surfaces of the projections and caliber peripheral surfaces that are adjacent to the inclined surfaces and face the end surfaces of the material to be rolled form substantially perpendicular angles.

4. The method for producing H-shaped steel according to claim 1 , wherein the projections formed in the first caliber and the second caliber have a tip angle of equal to or more than 25° and equal to or less than 35°.

5. The method for producing H-shaped steel according to claim 1 ,
wherein projections that are pressed against the divided parts to bend the divided parts are formed in the third caliber and subsequent calibers among the plurality of calibers, and
inclined surfaces of the projections and caliber peripheral surfaces that are adjacent to the inclined surfaces and face the end surfaces of the material to be rolled form substantially perpendicular angles.

6. The method for producing H-shaped steel according to claim 5 , wherein the projections formed in the second caliber and subsequent calibers among the plurality of calibers have tip angles sequentially increasing toward subsequent calibers.

7. The method for producing H-shaped steel according to claim 1 ,
wherein the plurality of calibers are four calibers of first to fourth calibers to shape the material to be rolled,
in the third caliber and the fourth caliber among the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed,
projections formed in the third caliber have a tip angle of equal to or more than 70° and equal to or less than 110°, and
projections formed in the fourth caliber have a tip angle of equal to or more than 130° and equal to or less than 170°.

8. The method for producing H-shaped steel according to claim 1 ,
wherein the projections formed in the first caliber and the second caliber have a tip angle of equal to or more than 25° and equal to or less than 35°,
projections that are pressed against the divided parts to bend the divided parts are formed in the third caliber and subsequent calibers among the plurality of calibers, and
inclined surfaces of the projections and caliber peripheral surfaces that are adjacent to the inclined surfaces and face the end surfaces of the material to be rolled form substantially perpendicular angles.

9. The method for producing H-shaped steel according to claim 1 ,
wherein the projections formed in the first caliber and the second caliber have a tip angle of equal to or more than 25° and equal to or less than 35°,
projections that are pressed against the divided parts to bend the divided parts are formed in the third caliber and subsequent calibers among the plurality of calibers, and
inclined surfaces of the projections and caliber peripheral surfaces that are adjacent to the inclined surfaces and face the end surfaces of the material to be rolled form substantially perpendicular angles, and
the projections formed in the second caliber and subsequent calibers among the plurality of calibers have tip angles sequentially increasing toward subsequent calibers.

10. The method for producing H-shaped steel according to claim 1 ,
wherein the projections formed in the first caliber and the second caliber have a tip angle of equal to or more than 25° and equal to or less than 35°,
the plurality of calibers are four calibers of first to fourth calibers to shape the material to be rolled,
in the third caliber and the fourth caliber among the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed,
projections formed in the third caliber have a tip angle of equal to or more than 70° and equal to or less than 110°, and
projections formed in the fourth caliber have a tip angle of equal to or more than 130° and equal to or less than 170°.

Assignees

• Nippon Steel Corp

Inventors

• Yamashita Hiroshi

Classifications

• B21B1/0883

  using forging or pressing devices · CPC title

• B21B2267/18

  Roll crown; roll profile · CPC title

• B21B2267/02

  Roll dimensions · CPC title

• B21B13/06

  with axes of rolls arranged vertically {, e.g. edgers} · CPC title

• B21B2013/106

  for sections, e.g. beams, rails · CPC title