JPS5855874B2 - Manufacturing method of cladding material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a cladding material by electroslag welding.

In recent years, as various facilities such as petrochemical plants have become larger, there has been an increase in demand for composite materials that combine corrosion-resistant materials and high-strength materials, so-called cladding materials. There is a roll pressure welding method in which a base material and a composite material are crimped together by rolling or cold rolling.In the roll pressure welding method, the surfaces of the base material and composite material are cleaned by pickling, polishing, etc., or the surfaces are cleaned. Electroslag welding has recently come to be used as a manufacturing method for clad materials in place of the roll pressure welding method. The clad material is made by interposing a slug between the facing surfaces of the base material and composite material separated by 30 to 40 mm, inserting an electrode into the slag, applying electricity, and overlaying the base material and composite material to form a clad material. In the conventional cladding method using electroslag welding, if the welding speed exceeds 20 mm/min, cracking defects are likely to occur in the weld. The amount of heat per unit area of the facing surface to be welded increases,
Since the penetration depth is 30 to 80 mm, the thickness of the base material and composite material must be 100 mm or more, and the drawback is that the base material and composite material are small in thickness and cannot be clad using the conventional electroslag welding method. was there.

The present invention eliminates the drawbacks of the conventional cladding method using electroslag welding, has a high welding speed, and enables cladding of base materials and composite materials with a small thickness of about 10 mm, and is a manufacturing method for cladding materials. This is what we propose.

In the present invention, a base material and a composite material having a thickness of 10 to 400 are transported from two directions above by guide rolls, and a The shaped space is filled with granular slag, an electrode is inserted into the slag, and electricity is applied to the base material, composite material, and electrode to melt the slag, and the resistance slag heat generated at that time melts the base material. and a method for manufacturing a clad material, which is characterized in that the facing surfaces of the composite material are melted and the composite material is pressed together with a drawing roll and then pulled out.

Embodiments of the present invention will be described below based on the drawings.

When the base material 1 and the composite material 2 are transferred from two directions by the guide roll 3, if the base material 1 and the composite material 2 are thin (10 to 30 mm), the base material 1 is transferred as shown in FIG. Immediately before the composite material 2 is brought into pressure contact with the drawing roll 4, it is made to face each other in a ■ shape.

In addition, in the case of a thick material in which the thickness of the base material 1 is 301nWL to 400mm, as shown in FIG. and composite material 2 are placed facing each other in a ■ shape.

In this way, the space between the facing surfaces of the base material 1 and composite material 2, which are opposed in the shape of a ■, is filled with granular slag (not shown, the illustration shows molten slag γ), and the slag 1 is filled with: As shown in FIG. 3, control is performed so that the tips of two or more electroslag heating electrodes 5 are always positioned according to the width of the base material 1.

Further, cooling copper plates 9 having cooling water pipes 8 are installed at both ends of the base material 1 and composite material 2 that face each other in a square shape to prevent the molten metal 6 and molten slag 7 from flowing out.

The base material 1, composite material 2, and electrode 5 are each connected to a power terminal of a three-phase AC power source (not shown), and when the three-phase AC power source (not shown) is energized, the granular slag (
(not shown) is heated by arc discharge and becomes partially molten.

Starting from this point, the temperature of the molten slag 7 rises to 1700-1800° C. due to Joule heat using the slag as a resistor, and the opposing surfaces of the base material 1 and composite material 2 become molten.

In this way, the facing surfaces of base material 1 and composite material 2 are sequentially
Melt while in a molten state at a welding speed of 0 mm/min,
Pressing is performed using a drawing roll 4, and the material is pulled out to form a cladding.

The clad material obtained as described above is hot-rolled or cold-rolled into a clad steel plate having a predetermined thickness.

In the present invention, when the welding speed is less than 30 mm/min, the amount of heat per unit area is large and the penetration depth is as deep as 8 mm or more. It was not possible to clad it, and the welding speed was 120mm/
If the welding speed exceeds 30 to 120 min, it is preferable to set the welding speed to 30 to 120 m/min.

Compared to the conventional cladding method using electroslag welding, the welding speed is faster, the amount of heat generated per unit area is smaller, and the penetration depth is shallower at 2 to 8mm, making it easier to manufacture cladding materials with smaller thicknesses. 1700~ as soon as possible
Since the surfaces of the base material and composite material are melted by the high-temperature slag heat of 1800° C., there is no need to clean the bonding surfaces of the base material and composite material before pressure welding, as in the conventional roll pressure welding method.

Next, examples of the present invention will be described.

Example 1 Table 1 shows the electroslag welding conditions such as the base material used, proportions and dimensions of the composite material, slag composition, electrode, heating power source, and welding speed.

As shown in Fig. 1, the base material 1 and composite material 2 shown in Table 1 are transported by guide rolls 3 while being curved from above, and immediately before being pressed by drawing rolls 4, they are made to face each other in a ■ shape. The granular slag is filled into the ■-shaped space under the welding conditions shown in , and an electrode is inserted into the slag and heated with electricity to melt the facing surfaces of the base material and composite material, while pressure welding is carried out using a drawing roll 4. At the same time, the clad material was drawn at the same speed as the welding speed.

Test pieces were taken from the joints of the cladding materials, and the depth of weld penetration was investigated. The results are shown in Table 2.

The thus obtained clad material was hot rolled to obtain a clad steel plate having a base material thickness of 3 mm and a composite material thickness of 3 mm.

6mm thicker than the clad steel plate (base metal part 3mm thick, composite material part 3mm thick)
) A test piece of 300mm width x 500mm length was taken, and the results of the bending test and shear strength based on JISGO601 are also shown in Table 2.

Example 2 Table 3 shows the electroslag welding conditions such as the base material used, the components and dimensions of the composite material, the slag composition, the electrode, the heating power source, and the welding speed.

As shown in Fig. 2, the base material 1 shown in Table 3 is conveyed vertically from the upper side using guide rolls while curving the composite material 2, and immediately before being pressed by a drawing roll, the base material 1 shown in Table 3 is conveyed in a V-shape facing each other. Fill the ■-shaped space with granular slag under the welding conditions shown in
An electrode was inserted into the slag, and the opposing surfaces of the base material and composite material were melted and pressed together with a drawing roll, and drawn at the same speed as the welding speed to form a cladding material.

Test pieces were taken from the joints of the cladding materials, and the depth of weld penetration was investigated. Table 4 shows the results.

The thus obtained clad material was hot rolled to obtain a clad steel plate with a base material thickness of 10 plates and a composite material thickness of 2 plates.

12 mm thicker than the clad steel plate (base metal part 10 mm thick, composite material part 2 mm thick)
A test piece of 7g711) x 300 width x 500 length was taken, and the sidewall test and shear strength were examined based on JIS, G 0601. The results are also shown in Table 4.

As described above, according to the method of the present invention, compared to the conventional electroslag welding method, the welding speed is faster, production efficiency is improved, and the penetration depth is shallower. Cladding is also possible, and there is no need to clean the surface as in the conventional roll pressure welding method, and manufacturing costs can be reduced.

Furthermore, the quality of the cladding material obtained by the method of the present invention was comparable to or higher than that of the conventional material.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing embodiments of the cladding material of the present invention. FIG. 3 is a sectional view taken along line A-A. 1...Base material, 2
...Mixture material, 3...Guide roll, 4.
...Pull-out roll, 5...Electrode, 6.
... Molten metal, 7... Molten slag, 8.
...Cooling water piping, 9...Copper plate for cooling.

Claims (1)

[Claims] 1 Immediately before the base material and composite material transferred from above are pressed together with a drawing roll, the ■ formed between the facing surfaces of the base material and composite material.
The shaped space is filled with slag, an electrode is inserted into the slag, and the resistive slag heat generated when the slag is heated with electricity melts the facing surfaces of the base material and composite material, and is pulled out by a drawing roll. A method for manufacturing clad material, which is characterized by pressure welding and pulling out.