JPS6021108A - Production of differential thickness plate - Google Patents

Abstract

PURPOSE:To produce simultaneously two sheets of stepped plates by superposing two sheets of steel slabs having the same shape via a release material and welding the circumferential edge thereof then subjecting the superposed slabs to rolling including stepped rolling at the end of the rolling stage and finally separating the rolled slab to two sheets at the part of the release material. CONSTITUTION:Two sheets of steel slabs 4A, 4B having the same shape are superposed via a release agent 5 such as sodium aluginate and the circumferential edge thereof is fully circumferentially or partially welded. The welded slab is rolled with a rolling mill having work rolls above and below and the rolling is completed by providing a step to the slab at the end of the rolling stage. The two rolled members 4A, 4B are then separated to two sheets in the part of the material 5 and two sheets of the stepped plates 4A', 5B' having excellent flatness of the flat surface are simultaneously produced.

Description

Detailed Description of the Invention The present invention provides a metal plate (hereinafter referred to as The present invention relates to a manufacturing method for a differential thickness plate (called a differential thickness plate).

The differential thickness plate has a shape as shown in FIG. 1, and is used, for example, as a shipbuilding material.

Face material of transverse bulkhead stiffener, transverse bulkhead curtain plate.

Used for web frame face plates, etc.

If one side A of the differential thickness plate 1 is not a flat surface, there will be a gap between the one side A and the mating material 2.

Problems arise in welding.

Conventionally, differential thickness plates have been manufactured by rolling a slab 4 to a predetermined position by a pair of upper and lower work rolls 3.3', as shown in FIG.

In the method for manufacturing the differential thickness plate described above, the following method has been adopted as a method for making the one surface a flat surface.

(1) As the lower work roll 3', use one whose diameter is as large as possible compared to the diameter of the upper work roll 3.

(2) Only one side A of the slab 4 is cooled and rolled with a temperature difference between one side A and the other side B, so that there is a step only on the other side B where the deformation resistance is small. Attach.

(3) By passing the double-sided stepped plate, which has undergone final finishing at a specific temperature range, through a roller table,
．． Make one side hf flat.

However, in reality, there are limitations in terms of equipment and operation.

The current situation is that it is not very effective.

This invention was made to solve the above-mentioned problems.

Two slabs are stacked on top of each other via a release agent, the two stacked slabs are subjected to rolling including step rolling at the end of the rolling process, and after the rolling is completed, the two slabs are peeled off. In this way, the present invention is characterized in that it produces a plate of different thickness, which is flat on one side and has a step formed on the other side.

Here, the step rolling refers to rolling in which steps are formed on both sides of the plate. As a specific example of step rolling, the first
As shown in the figure, during rolling, the upper and lower work rolls 3,
There is a method of changing the roll interval of 3'. In FIG. 1, the distance between the rolls is increased during rolling to allow the slab 4 to pass through.

On the contrary, the distance between the rolls may be reduced during rolling.

Further, as another step rolling method, there is a method in which rolling is started from one end of the slab and the rotation direction of the rolls is reversed halfway through rolling.

Step rolling may be carried out over two or more passes, but one step rolling is preferred because the difference in thickness between the thick and thin portions of a differential thickness plate that is normally required is not that large.

It is preferable to carry out the rolling process at the end of the rolling process, that is, near the final target dimensions (plate length, plate width, plate thickness).

Normally, it is sufficient to carry out step rolling at the end of the rolling process. That is, it is preferable that after the slab is made into a plate having a uniform thickness over the entire length in the lengthwise direction by the internal thickness of the differential thickness plate by normal rolling, the above-mentioned step rolling is performed in the final step. Note that in the present invention, two slabs are used to simultaneously manufacture two plates with different thicknesses.
The thickness is twice the thickness of the thick portion.

One embodiment of this invention will be explained from the woman's perspective with reference to the drawings.

First, as shown in FIG. 3(A), one of the slabs 4
Apply a release agent such as sodium alginate to the top surface of A.

The other slab 4B having the same shape as the slab removed is placed on the slab body. After this, as shown in the same figure (B).

The contact outer peripheral portions of the slabs 4A and 4B are welded partially or over the entire circumference. Next, these two stacked slabs 4A and 4B are subjected to rolling including step rolling at the end of the rolling process, as shown in FIG. 4(0). After rolling,
As shown in Figure (D), the two slabs are separated. As a result, two plates 4'A and 4'B of different thickness, each having a flat surface on one side and a step on the other surface, can be manufactured at the same time.

Next, ★Administration of this invention will be explained.

Sodium alginate was applied to the top surface of a slab with a short side length of 1350rnjn, a long side length of 1700mm, and a thickness of 150M, and on top of this, another slab of the same shape as the above slab was placed, and the two sheets were stacked together. After heating the slab to the specified temperature,
Rolling was carried out according to the rolling schedule shown in Table 1.

In Table 1, up to 11 passes are normal rolling, and 1
The two passes were step rolling, and the above-mentioned method of reversing the rolls in the middle of rolling was adopted as the one-step rolling.

Table 1 After such rolling, the two slabs were peeled off. As a result, a differential thickness plate was obtained in which the thickness of the thick portion was 10 nm and the thickness of the thin portion was 15 m.

The flatness of this differential thickness plate was almost flat.

As described above, according to the present invention, an extremely useful effect is brought about, such as being able to simultaneously manufacture two plates with different thicknesses each of which has a substantially completely flat surface.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the differential thickness plate, and FIG. 2 is a perspective view of the differential thickness plate. Explanatory drawings showing the manufacturing method of differential thickness plates, Figures 3(A) to (
D) is a manufacturing process diagram of an embodiment of the present invention. In the drawing. l... Differential thickness plate 2... Laminating material 3.3'...
・Work roll 4...Slab 4A, 4B...Slab 4'A, 4'B...Differential thickness plate 5...Removal agent Applicant Nippon Kokan Co., Ltd. Agent Natsuo Shioya (and 2 others) ) 1st calendar day 1 (A) (C) (B) B (D)

Claims (1)

[Claims] Two slabs are stacked on top of each other via a release agent, the two stacked slabs are subjected to rolling including step rolling at the end of the rolling process, and after the rolling is completed, the two slabs are peeled off. In this way, the present invention is characterized in that it produces a differential thickness plate having one surface flat and the other surface having a step. Method for manufacturing differential thickness plates.