KR20100072349A - Magnesium hot rolling method and magnesium hot rolling apparatus - Google Patents

Abstract

A magnesium hot rolling method comprises a first rolling step performing reciprocal rolling of magnesium plates (M0, M1) between an upstream side heating furnace (2) arranged on the upstream side of a rolling machine (1) for heating the magnesium plates (M0, M1) and a downstream side heating furnace (3) arranged on the downstream side of the rolling machine (1) for heating the magnesium plates (M0, M1), and a second rolling step performing reciprocal rolling of the magnesium plates (M0, M1) while retaining heat in the upstream side and downstream side ends thereof between an upstream side heat retention device (5) for carrying/heat-retaining the heated magnesium plates (M0, M1) and a downstream side heat retention device (6) for carrying/heat-retaining the heated magnesium plates (M0, M1). According to the magnesium hot rolling apparatus of the present invention and the magnesium hot rolling method employing the apparatus, quality of a product can be prevented from deterioration due to temperature variation during hot rolling of a magnesium alloy.

Description

Magnesium hot rolling method and magnesium hot rolling apparatus

The present invention relates to a magnesium hot rolling method and a magnesium hot rolling apparatus.

This application claims priority based on Japanese Patent Application No. 2007-269058 for which it applied on October 16, 2007, and uses the content here.

To manufacture a magnesium sheet from a magnesium alloy, a round bar-shaped billet having a diameter of 300 to 400 mm and a length of 500 to 600 mm is formed into a thick plate having a thickness of 10 mm or less, for example, by hot extrusion. The thick plate is cut into a predetermined length (for example, 3 m) to form a cut plate, and the cut plate is rolled to a thickness of 1 mm or less by rough rolling.

By the way, in order to roll at a normal temperature, magnesium alloy is easy to crack, even if it increases pressure, so it is preferable to roll at hot temperature.

As a prior art example of the apparatus which hot-rolls a magnesium alloy, it is disclosed by FIG. 1 of patent document 1, and FIG.

The hot rolling apparatus disclosed in these patent documents includes a rolling mill for rolling while reciprocating a magnesium alloy, and two heating furnaces disposed upstream and downstream of the rolling mill. It is heated by rolling with a rolling mill.

Patent Document 1: Japanese Patent No. 3351863 Patent Document 2: Japanese Patent No. 3821074

However, in the hot rolling apparatus disclosed in the above patent document, since there are only heating furnaces on both sides of the rolling mill, the end of the magnesium-cutting plate is pushed out of the heating furnace as the magnesium-cutting plate is lengthened by reciprocating rolling. There is a flaw that comes out cool. This is because the temperature fluctuation during hot rolling of the magnesium cut sheet causes poor dimensional accuracy and deterioration of the finished product.

This invention is made | formed in view of the above-mentioned situation, and an object of this invention is to propose the magnesium hot rolling method and apparatus which can prevent the quality fall of the product by the temperature change during hot rolling of a magnesium alloy.

In order to solve the said subject, the following apparatus and method were employ | adopted in this invention.

According to a first aspect of the present invention, a reciprocal rolling of the magnesium plate is performed between an upstream heating furnace disposed on an upstream side of a rolling mill and heating a magnesium plate, and a downstream heating furnace disposed downstream of the rolling mill and heating the magnesium plate. First rolling process; An upstream side heat preservation apparatus which is disposed further upstream of said upstream side heating furnace and conveys and heats said magnesium plate heated by said upstream side heating furnace, and is arranged further downstream of said downstream side heating furnace and said downstream side Employing a magnesium alloy hot rolling method having a second rolling step of reciprocally rolling the magnesium plate while warming up and down each of the plate end portions between downstream downstream insulation devices for conveying and insulating the magnesium plate heated by a heating furnace. It was.

In the magnesium alloy hot rolling method according to the first invention, the downstream insulation is performed while applying tension to the magnesium plate rolled to a predetermined thickness by a tension applying device disposed downstream of the downstream insulation device. You may have the winding process wound by the winding machine arrange | positioned further downstream of an apparatus.

Moreover, as 2nd invention which concerns on this application, The rolling mill which reciprocally rolls a magnesium plate; An upstream heating furnace disposed at an upstream side of the rolling mill to heat the magnesium plate; A downstream heating furnace arranged downstream of the rolling mill to heat the magnesium plate; An upstream side heat preservation apparatus arranged at a further upstream side of said upstream side heating furnace to heat the conveyance of said magnesium plate heated by said upstream side heating furnace and an upstream end; The magnesium alloy hot rolling apparatus which was provided further downstream of the said downstream side heating furnace and which conveys the said magnesium plate heated by the said downstream side heating furnace, and heat-retains the downstream end part was employ | adopted.

In the magnesium alloy hot rolling apparatus according to the second invention, a plurality of sets are respectively arranged between the rolling mill and the upstream heating furnace and between the rolling mill and the downstream heating furnace to sandwich the magnesium plate in the thickness direction, You may be provided with the pinch roll which adjusts a conveyance speed.

Moreover, in the magnesium alloy hot rolling apparatus which concerns on the said 2nd invention, the heat roll may be sufficient as the plurality of sets of pinch rolls provided in the work roll of the said rolling mill, and the upstream and downstream of the said rolling mill.

Further, the magnesium alloy hot rolling device according to the second invention, comprising: a tension imparting device disposed on a downstream side of the downstream side thermal insulation device to impart tension to the magnesium plate; The winding device which is arrange | positioned further downstream of the said tension provision apparatus and winds up said magnesium plate may be provided.

According to the present invention, since the magnesium plate is rolled while heating and keeping it warm over approximately the entire length, the temperature drop of the magnesium plate can be suppressed, and the dimensional accuracy of the product due to the temperature variation during hot rolling can be prevented, and the quality can be prevented. The quality of the finished product can be kept good.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic front view which shows schematic structure of the hot rolling apparatus in one Embodiment of this invention.
It is a schematic diagram which shows schematic structure of a leveler.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of this invention is described with reference to drawings.

FIG. 1: is a schematic front view which shows schematic structure of the hot rolling apparatus 100 (magnesium alloy hot rolling apparatus) in this embodiment.

As shown in FIG. 1, the hot rolling apparatus 100 which concerns on this embodiment is the rolling mill 1, the 1st heating furnace 2, the 2nd heating furnace 3, the pinch roll 4, and the 1st table. The roller 5, the 2nd table roller 6, the winding machine 7, and the pinch roll 8 are provided.

The rolling mill 1 has a pair of work roll 1a which opposes in parallel, and the drive source (not shown) which rotationally drives the said work roll 1a.

The work roll 1a is a heating roll in which the surface temperature is raised to an appropriate temperature, and the magnesium cut plate M0 is sent out while feeding the magnesium cut plate M0 (magnesium plate) passing through the work roll 1a in one direction. ) Is given a predetermined pressure. Thereby, the rolling mill 1 lengthens the magnesium cut board | plate material M0, reducing thickness.

Moreover, the rolling mill 1 performs reciprocal rolling by inverting the conveyance direction of the magnesium cutting board material M0 at a predetermined timing. Thereby, the rolling mill 1 rolls the magnesium cut board | plate material M0 from thickness 6mm, about 3m in length to thickness 1mm, about 18m in length, for example.

The said magnesium cutting board material M0 (magnesium plate) which is the workpiece | work of this hot rolling apparatus 100 is a board | plate material which consists of magnesium alloys.

The 1st heating furnace 2 (upstream heating furnace) is the heating furnace arrange | positioned upstream of the rolling mill 1. As shown in FIG. The 2nd heating furnace 3 (downstream heating furnace) is the heating furnace arrange | positioned downstream of the rolling mill 1. As shown in FIG.

These pair of heating furnaces 2 and 3 have the length more than the length of the magnesium cutting board material M0 before rolling, and are equipped with the heater and a conveyance roller (all not shown). The magnesium cut sheet material M0 is heated to predetermined temperature (about 100-350 degreeC, 200-300 degreeC is preferable) with a heater, and a magnesium cutting board material M0 is conveyed by a conveyance roller.

The pinch roll 4 is a heating roll which heated up the surface temperature to a suitable temperature, and auxiliary conveys the magnesium cutting board M0 which reciprocates along with the reciprocation rolling by the rolling mill 1. As shown in FIG. These pinch rolls 4 are respectively arranged in multiple sets between the rolling mill 1 and the 1st heating furnace 2, and between the rolling mill 1 and the 2nd heating furnace 3, respectively.

These pinch rolls 4 provide appropriate tension to magnesium-cutting board | plate material M0 rolled by the rolling mill 1 by adjustment of a conveyance speed.

The 1st table roller 5 (upstream thermostat) is arrange | positioned upstream of the 1st heating furnace 2, and the 2nd table roller 6 (downstream thermostat device) of the 2nd heating furnace 3 Disposed downstream. Each said table roller 5 and 6 has convey rollers 5a and 6a and heat retention covers 5b and 6b.

When the magnesium cut board | plate material M0 is reverse-rolled by the rolling mill 1 and lengthens, the edge part will be pushed out from the heating furnaces 2 and 3. The table rollers 5 and 6 convey and support the edges pushed out from the heating furnaces 2 and 3 of the magnesium cutting plate M0 by the conveying rollers 5a and 6a, and at the same time, the heat retaining covers 5b and 6b. Cover by and cut off from the outside air. As a result, the table rollers 5 and 6 heat-retain so that the heat of the magnesium cutting board M0 may not run away. In addition, the edge part thermal insulation part located downstream from the magnesium cut board | plate material M0 at the time of reverse rolling enters into a heating furnace at the time of rolling to the next reverse direction. In addition, the edge part heating part located in the downstream side exists in the heat retention apparatus at the time of rolling in a reverse direction, and can reduce temperature fall of an edge part by repeating this alternately.

The winder 7 winds the manufactured product, ie, magnesium sheet M1 (magnesium plate), after the magnesium cut board | plate M0 is rolled.

The pinch roll 8 (tension applying device) is disposed in front of the winder 7, and by adjusting the conveying speed of the magnesium sheet M1, the magnesium sheet M1 in the reverse direction to the winding direction of the winder 7. ) To give tension.

In such a configuration, the hot rolling apparatus 100 performs rough rolling of the magnesium cutting plate M0. Hereinafter, the operation of the hot rolling apparatus 100 will be described.

First, magnesium cutting board | substrate M0 which is the object rolled by this hot rolling apparatus 100 hot-extrudes the round bar-shaped billet of about 300-400 mm in diameter and about 500-600 mm in length (about 100-300 degreeC, It is manufactured by molding into a thick plate having a thickness of 10 mm or less (for example, 6 mm), for example, and cutting the thick plate to a predetermined length (for example, 3 m).

Since the crystal grains of magnesium constituting the magnesium-cutting board member M0 formed by hot extrusion are mechanically refined by being extruded, they have high strength, high quality, are difficult to crack, and have good press formability.

Magnesium cutting board | plate M0 is conveyed from the 1st table roller 5 to the 1st heating furnace 2, and predetermined temperature (about 100-350 degreeC, 200-300 degreeC) is preferable in the 1st heating furnace 2. Is heated to the rolling mill 1.

The rolling mill 1 conveys to the 2nd heating furnace 3, rolling the magnesium cut board | plate material M0. The temperature of the magnesium cutting board M0 drops slightly while moving from the first heating furnace 2 to the second heating furnace 3. However, since the work roll 1a and the several pinch rolls 4 are a heating roll and are heated again to the said predetermined temperature in the 2nd heating furnace 3, temperature fluctuations are small.

The hot rolling device 100 reverses the rolling direction when the terminal 1 of the magnesium cut plate M0 passes through the rolling mill 1. The hot rolling apparatus 100 repeats this and reciprocally rolls the magnesium cutting board M0, and sequentially reduces the thickness of the magnesium cutting board M0 to manufacture the magnesium sheet M1.

Here, the specific example of the various numerical value of the rough rolling by the hot rolling apparatus 100 which is shown in following Table 1 is shown.

Pass No. Thickness at the time of import
(mm) Thickness reduction
(mm) Rolling temperature
(℃) Rolling speed
(m / min) Rolling load
(ton) One 6.00 1.80 200 10 180 2 4.20 1.26 200 10 165 3 2.94 0.88 200 10 150 4 2.06 0.62 200 10 140 5 1.44 0.43 200 10 135

            Final thickness: 1.01mm

In the above specific example, the material of the magnesium cut plate M0 is AZ31B, the dimension is 6.00 mm in thickness, 300 mm in width, and 3000 mm in length. The diameter of the work roll 1a is 400 mm, the barrel length is 500 mm, and the diameter of the pinch roll 4 is 250 mm.

In the above example, the heating temperature in the heating furnaces 2 and 3 is 220 ° C, the pinch rolls 4 and the work roll 1a are heating rolls in which a heater is incorporated, and the surface temperature of the heating roll is 200 ° C. .

And the said example makes magnesium cutting board | substrate M0 of thickness 6.00mm into the magnesium sheet M1 of thickness 1.01mm by reciprocating rolling of 5 passes (2 reciprocating half), and after 5 passes to the winding machine 7, It is wound by.

The magnesium cutting plate M0 is lengthened as it is rolled, and when the end passes through the rolling mill 1, the end including the start end is pushed out of the heating furnaces 2 and 3.

The table rollers 5 and 6 support the edge part pushed out from the heating furnaces 2 and 3 with the conveyance rollers 5a and 6a, and heat-retain by the heat insulation covers 5b and 6b.

Referring to this in more detail in FIG. 1, for example, the magnesium cut sheet M0, which was the length L0 before rolling, is rolled in the section A1 until the length L1 is obtained (first rolling step), and the length L2 is exceeded the length L1. It is rolled up in the section A2 (second rolling step), and wound up (winding step) until

That is, in this hot rolling apparatus 100, segment A1, ie, 1st heating furnace 2-rolling mill 1-2nd by a 1st rolling process, while magnesium cutting board | substrate M0 is length L0-L1 is performed. Reciprocating rolling between the heating furnaces (3). Section A2, ie, 1st table roller 5-1st heating furnace 2-rolling mill 1-2nd heating by a 2nd rolling process, until magnesium cutting board M0 exceeds L1 and becomes L2. Reciprocating rolling between the furnace 3 and the 2nd table roller 6 is carried out. Then, the finished product, that is, the magnesium sheet M1 is wound by the winding machine 7.

Thereby, the magnesium cut board | plate M0 is heated or insulated over the whole length, and is maintained at the temperature of a substantially constant range. Therefore, the fall of the quality of the product by the temperature change of the magnesium cutting board M0 can be prevented, and the quality of the finished product, ie, the magnesium sheet M1, can be kept favorable.

By the way, since the magnesium cutting board M0 in rolling is high temperature, when the high pressure is applied also in parts other than the rolling mill 1, there exists a possibility that the pressed trace may remain. On the other hand, in this hot rolling apparatus 100, pinching of the pinch roll 4 by disperse | distributing the pinch roll 4 small by sandwiching the magnesium cutting board | substrate M0 in multiple positions with a plurality of sets of pinch rolls 4, The risk of leaving the pressed trace by the roll 4 is reduced.

Then, when the magnesium cut sheet M0 is reduced to a predetermined thickness (for example, about 1 mm) and becomes a magnesium sheet M1, the hot rolling apparatus 100 is wound by the winding machine 7 with a magnesium sheet ( Wind up M1) to make a coil material.

In that case, the pinch roll 8 adjusts the conveyance speed of the magnesium sheet M1 so that predetermined tension may be applied to the magnesium sheet M1 wound by the winding machine 7, and the winding direction of the winding machine 7 may be carried out. The tensile force is given to the magnesium sheet M1 in the reverse direction of.

According to the hot rolling apparatus 100 of this invention, since rolling is carried out over the whole length of the magnesium cutting board M0 while heating and keeping warm, it suppresses the temperature drop of the magnesium cutting board M0, and changes the temperature variation during hot rolling. It is possible to prevent the deterioration of the product according to, and to maintain a good quality of the finished product, that is, the magnesium sheet (M1).

In this embodiment, although the pinch roll 8 is used as a tension provision apparatus, the tension provision apparatus may be sufficient as the leveler which planarizes the magnesium sheet M1.

Here, the leveler is flattened magnesium sheet M1 by staggering a combination of three or more rollers so that the cross section becomes a honeycomb in two stages as shown in FIG. 2 and passing a sheet-like material between these rolls. do.

According to the magnesium hot rolling apparatus of the present invention and the magnesium hot rolling method using the same, poor dimensional accuracy and quality deterioration of the product due to temperature fluctuation during hot rolling can be prevented, and the quality of the finished product can be maintained satisfactorily.

100 hot rolling equipment (magnesium hot rolling equipment)
1 rolling mill
2 first heating furnace (upstream heating furnace)
3 second heating furnace (downstream heating furnace)
4 pinch rolls (feed roller pair)
5 first table rollers (upstream thermostat)
6 second table roller (downstream thermostat)
7 winder
8 pinch rolls (tension device)
M0 magnesium cutting board (magnesium plate)
M1 magnesium sheet (magnesium plate)

Claims (6)

A first rolling step of reciprocally rolling the magnesium plate between an upstream heating furnace disposed upstream of the rolling mill and heating the magnesium plate, and a downstream heating furnace disposed downstream of the rolling mill and heating the magnesium plate. ;
An upstream side heat preservation apparatus which is disposed further upstream of said upstream side heating furnace and conveys and heats said magnesium plate heated by said upstream side heating furnace, and is arranged further downstream of said downstream side heating furnace and said downstream side And a second rolling step of reciprocally rolling the magnesium plate while warming each of the upstream and downstream side plate end portions between the downstream side insulation devices for conveying and insulating the magnesium plate heated by a heating furnace. The method of claim 1,
Winding process wound up by the winding machine arrange | positioned further downstream of the said downstream side thermostat, while giving tension with respect to the said magnesium plate rolled to predetermined thickness by the tension provision apparatus arrange | positioned downstream of the said downstream side thermostat. Magnesium alloy hot rolling method having a. Rolling mill for reciprocating a magnesium plate;
An upstream heating furnace disposed at an upstream side of the rolling mill to heat the magnesium plate;
A downstream heating furnace arranged downstream of the rolling mill to heat the magnesium plate;
An upstream side heat preservation apparatus arranged further upstream of said upstream side heating furnace to heat the conveyance of said magnesium plate heated by said upstream side heating furnace and also upstream end;
And a downstream side heat insulating device disposed further downstream of the downstream side heating furnace and configured to carry the conveyance of the magnesium plate heated by the downstream side heating furnace and the downstream end portion. The method of claim 3,
Magnesium alloy hot rolling provided with the pinch roll which arranges a plurality of sets, respectively, between the said rolling mill and the said upstream heating furnace, and between the said rolling mill and the said downstream heating furnace, and clamps the said magnesium plate in thickness direction, and adjusts a conveyance speed. Device. The method of claim 4, wherein
The magnesium alloy hot rolling apparatus of the work roll of the said rolling mill and the plurality of sets of pinch rolls provided in the upstream and downstream of the said rolling mill is a heating roll. The method according to claim 3 or 4,
A tension imparting device disposed on a downstream side of said downstream insulating device to impart tension to said magnesium plate;
And a winder disposed further downstream of the tension applying device to wind the magnesium plate.

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