JPH09262604A - Method for rolling copper and copper base alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the machinability of surface cutting work process at the time of rolling a slab cast billet of copper and copper base alloy which is soft and whose machinability is defective in the process of surface cutting work. SOLUTION: In a time of rolling a slab cast billet of copper and copper base alloy which is soft and whose machinability is defective in the surface cutting work, after a slab is hot-rolled to a prescribed thickness, it is cooled to the normal temperature on a rolling table, further with the same rolling mill, it is cold-rolled to the target thickness and the surface hardness is raised, the machinability of surface cutting work is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot rolling method for slab slabs of copper and copper-based alloys, and particularly to copper and copper-based alloys which are soft and have poor machinability in the surface cutting process After hot rolling the slab to a predetermined plate thickness when rolling a slab slab, it is cooled to room temperature on a rolling table, and further cold-rolled to a target plate thickness in the same rolling mill, The present invention relates to a method for rolling copper and a copper-based alloy, which is characterized by improving machinability in a surface cutting step.

[0002]

Hot rolling of copper and copper-based alloys reduces the deformation resistance of the material by heating the cast slab and bloom to a predetermined temperature, and applies a large force to the two rolls in a short time. On the other hand, the slab and the bloom are passed between the rolls to process them into a predetermined plate thickness. The hot rolling mill is classified into a reverse mill that reciprocates around a set of rolls and a tandem mill that performs rolling in one direction using a plurality of sets of rolls. With copper and copper-based alloys, fine oxide scales and surface defects occur on the plate surface during hot rolling, so 0.3 mm from the surface after hot rolling.
It is necessary to cut a range of ~ 0.8 mm to remove oxide scale and surface defects.

On the other hand, the plate after hot rolling is cut with a flat-edged milling cutter made of high-speed steel and cemented carbide. The cutter used for cutting after rolling is required to cut the surface of a wide plate with high efficiency,
Both width and diameter are large, for example, cutter width 800-1
A dimension of 600 mm and an outer diameter of 200 to 300 mm is common. In soft materials such as copper and copper-based alloys, especially pure copper, chips are welded to the cutting edge to damage the finished surface, form a built-up cutting edge, tear the finished surface, and cannot provide stable surface quality. In this case, in order to prevent defects due to cutting, it is general to change the cutting speed or change the material of the cutting tool.

[0004]

However, changing the cutting speed requires a large-scale remodeling of the equipment and significantly deteriorates productivity, and changing the cutting tool shortens the tool life remarkably. There was a problem such as making it happen.

The present invention has been made in view of the above circumstances, and is performed in the surface cutting step when rolling a slab cast piece of copper and a copper-based alloy that is soft and has poor machinability in the surface cutting step. The object is to improve the machinability.

[0006]

Means for Solving the Problems The present inventor has conducted extensive studies in order to achieve the above object. As a result, in order to improve the machinability in the surface cutting process after hot-rolling copper and copper-based alloys, we found the need to increase the hardness of copper and copper-based alloys before surface cutting, and increased the hardness. To do this, when rolling slab slabs of copper and copper-based alloys, the slab is hot-rolled to a prescribed plate thickness, then cooled on a hot-rolling table and cooled to the target thickness with the same rolling mill. It was found that the hot-rolling improves the machinability of copper and copper-based alloys, and has completed the present invention.

That is, the method for rolling copper and copper-based alloys according to the present invention is a method for rolling a slab of copper and a copper-based alloy which is soft and has poor machinability in the surface cutting step. After being hot-rolled to the plate thickness of the above, it is cooled to room temperature on the rolling table, and further cold-rolled to the specified plate thickness in the same rolling machine to improve the machinability in the surface cutting process. It is what

[0008]

DETAILED DESCRIPTION OF THE INVENTION Next, the operation of the present invention will be described. In the present invention, the reason for performing cold rolling after hot rolling is to improve the machinability of the surface cutting step. From this point of view, in the present invention, it is desirable that the hardness is 100 HV or more in the cold rolling after the hot rolling. However, as the hardness increases, the cutting resistance increases and the tool wear increases, so the upper limit is 3
00HV is desirable. The reason why cold rolling is performed by the same rolling mill after hot rolling is that the copper and copper-based alloy strips can be manufactured at low cost without increasing the number of manufacturing steps.

The present invention is intended for relatively soft copper and copper alloys such as tough pitch copper, but does not limit the components of copper and copper-based alloys, and the range of their mixing ratio.
Further, the slab dimensions, heating temperature, hot rolling processing conditions, cooling method, cold rolling processing conditions, and surface cutting conditions are merely examples, and the slab dimensions, heating temperature, hot rolling processing history,
It does not limit the range of the cooling method or the cold rolling process condition.

[0010]

EXAMPLES Next, examples and comparative examples according to the present invention will be described. In this example, hot rolling and surface cutting were performed using a slab of tough pitch copper containing 0.03% oxygen, which was cast by a vertical continuous casting machine.

The following experiment was conducted to clarify the effect of the present invention. 180m thickness cast in vertical continuous casting furnace
m tough pitch copper slab 800 ℃ by continuous heating furnace
And after hot rolling to a thickness of 15 mm with a hot rolling mill, cooling to room temperature on the table of the hot rolling mill,
Further, cold rolling was performed to 8 mm in the hot rolling mill. The tough pitch copper was cut by 0.4 mm in the surface cutting step, and the surface defects after cutting were observed.

As a comparative example, a 180 mm thick tough pitch copper slab cast in a vertical continuous casting furnace is heated to 800 ° C. in a continuous heating furnace, and a thickness of 8 is obtained in a hot rolling mill.
Hot rolling was performed up to mm, 0.4 mm was cut in the surface cutting step, and the surface defects after cutting were observed.

As a result of the present invention, the number of surface defects observed on the surface cutting line is shown in Table 1 together with Comparative Examples. As is clear from Table 1, as compared with the conventional hot-rolling-only material, the results were obtained by performing hot-rolling with a hot-rolling mill to a predetermined plate thickness and then performing cooling and cold-rolling with the same rolling mill. The material is
Surface defects after surface cutting were reduced.

[0014]

[Table 1]

[0015]

According to the present invention described above, when rolling a slab slab of copper and a copper-based alloy that is soft and has poor machinability in the surface cutting step, the slab is heated to a predetermined plate thickness. After cold rolling, it is cooled to room temperature on the rolling table, and further cold-rolled to a predetermined plate thickness in the same rolling machine to improve the machinability in the surface cutting step.
Surface defects during surface cutting can be reduced.

Claims (3)

[Claims] 1. When rolling a slab slab of copper and a copper-based alloy that is soft and has poor machinability in the surface cutting step, the slab is hot-rolled to a predetermined plate thickness and then on a rolling table. A method for rolling copper and copper-based alloys, which comprises cooling to room temperature and further cold rolling to a target plate thickness in the same rolling mill to improve machinability in a surface cutting step. 2. When rolling a slab slab of copper and a copper base alloy that is soft and has poor machinability in the surface cutting step, the slab is hot-rolled to a predetermined plate thickness and then on a rolling table. A method for producing copper and a copper-based alloy, comprising cooling to room temperature, further cold rolling to a target plate thickness in the same rolling mill to increase the surface hardness, and then performing surface cutting with a cutter. 3. A hardness of 100 after cold rolling after hot rolling.
The method according to claim 1, wherein the method is adjusted to HV to 300 HV.