JPH04333371A - Auxiliary material for welding - Google Patents

Abstract

PURPOSE:To improve the adaptability of the auxiliary material for arc shielded welding, etc., when the material is repetitively used and where particularly high corrosion resistance is requested by imparting excellent corrosion resistance together with heat resistance to this material. CONSTITUTION:The auxiliary material 30 for welding is formed of ceramics contg. alumina. The above-mentioned alumina may be preferably incorporated at >=30wt.%, further preferably >=5Owt.% into the ceramics. The alumina is preferably incorporated as an essential component therein.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a welding auxiliary material, which
It mainly relates to a welding auxiliary material that is used to cover a welded part during welding, to block the outflow of molten metal, to mold the molten metal into a certain shape, or to isolate the welded part from the outside air.

0002

2. Description of the Related Art Conventionally, in arc stud welding, a cylindrical welding aid 2 called an arc shield (ferrule) has been used, as shown in FIG. When welding the stud 4 to the workpiece 6, the arc shield 2 is fitted onto the stud 4 as shown in the figure to cover the welded part of the stud 4 (the lower end of the stud 4), and is used to insert molten metal into the mold. Isolate the welding area from the outside air.

[0003] Conventional arc shields are cylindrical, one is attached to each stud, and after welding, they are generally crushed with a hammer or the like and removed from the welded area, so they cannot be recycled again. It was an unusable consumable item.

[0004] On the other hand, for example,
As disclosed in Publication No. 69 and Japanese Unexamined Patent Publication No. 141379/1980, a cylindrical arc shield is divided into a plurality of pieces, for example, two pieces, and these two arc shield pieces are connected and separated by a welding machine. The two arc shield segments are brought into contact and butted against each other to form a cylindrical arc shield, and the cylindrical arc shield covers the welded part of the stud as shown in FIG. A method has been proposed in which welding is performed, and after the welding is completed, both of the arc shield segments are separated from each other and removed from the welded stud. According to this method, arc stud welding can be repeated many times using the same arc shield.

[0005] When the arc shield is repeatedly used as described above, the arc shield becomes extremely hot during welding and easily breaks, so it must be made of a material with excellent thermal shock resistance. 1986-18
Publication No. 1269 mentions ceramics (the specific ceramic name is not listed), and JP-A No. 5
No. 9-141379 mentions silicon nitride ceramics.

[0006]

[Problems to be Solved by the Invention] By the way, there are many types of ceramics, each of which has different characteristics. Therefore, when forming an arc shield using ceramics, it is desirable to select and form a ceramic that better matches the properties required for the arc shield from among various ceramics, rather than simply forming it using any ceramic.

[0007] However, as mentioned above, the arc shield becomes extremely hot during welding (1300°C or higher), making it susceptible to deterioration and cracking, and since the inner surface is in contact with high-temperature molten metal, it is corroded by the high-temperature molten metal. Cheap. Therefore, especially in the case of an arc shield that is used repeatedly, it is required to have both excellent heat resistance and corrosion resistance, but depending on the welding conditions, etc., it is required that the corrosion resistance is particularly excellent. There are cases.

[0008] In view of the above circumstances, an object of the present invention is to provide a welding auxiliary material such as an arc shield, which has excellent heat resistance and, in particular, sufficiently excellent corrosion resistance.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the welding auxiliary material according to the present invention is made of alumina (Al2O3
) is characterized by being made of ceramics containing.

[0010] When containing the above alumina, 3
It is preferable that the content is 0% by weight or more, preferably 50% by weight.
It is more preferable if the content is above. Moreover, it is more preferable if it is contained as a main component, that is, as a component with the highest content. In addition, as alumina, high-temperature type α-A
l2 O3 is preferably used.

[0011]

[Function] Alumina has strong chemical bonds and therefore has extremely high chemical and physical stability, and also has a relatively high melting point of 2050°C and excellent heat resistance.

[0012] The welding auxiliary material made of ceramics containing alumina has the above-mentioned characteristics of alumina, and therefore has extremely high physical and chemical stability, and has extremely excellent corrosion resistance particularly against molten metal. Furthermore, since the melting point is 2050° C., which is higher than the general welding temperature of, for example, 1300° C. or higher, there is little material deterioration due to high temperatures during welding, and in this sense, it has sufficient heat resistance.

[0013] Therefore, the welding auxiliary material made of ceramics containing alumina has heat resistance and particularly excellent corrosion resistance, and is suitable for use when repeated use and particularly high corrosion resistance is required. be able to.

[0014]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the welding auxiliary material according to the present invention. The welding auxiliary material shown in this embodiment is a substantially semi-cylindrical arc shield divided body 30 formed by dividing a cylindrical arc shield into two parts.

A plurality of communication grooves 32 having a predetermined opening area are formed on the lower surface of the arc shield division body 30 to communicate the inside and outside of the arc shield for degassing during welding, and the inner surface 34 will be explained below. As shown in FIG. 5, a stud insertion hole is formed that is slightly larger than the outer diameter of the stud 80, and a recess 38 is formed on the outer surface 36 for holding the arc shield divided body 30 in the arc shield holding section described below. has been done.

FIG. 2 is a front view showing an arc stud welding machine that performs arc stud welding using the arc shield division body 30, and FIG. 3 is a right side view of the welding machine shown in FIG.
Figure 4 is an enlarged view taken along the line IV-IV in Figure 2, and Figure 5 is Figure 4.
It is a sectional view taken along the line V-V of

The illustrated welding machine 42 has a base 44 and a base 4.
A fulcrum pin 48 is attached to each of the two legs 46 fixed to the
A pair of levers 50 are rotatably supported through the levers 50, one end is rotatably connected to the upper end of each lever 50 through a joint pin 52, and the other end is rotatably connected through a joint pin 54. A pair of links 56 that are possibly connected, a handle 58 that is fixed to the one end of one link 56 and extends in the left and right lateral directions (in the direction of arrow B in FIG. 2), and both links 5
A long hole member 62 is fixed to the base 44 and has a long hole 60 extending in the vertical direction (direction of arrow C in FIG. 2) through which a joint pin 54 connecting the other ends of the base 4 is inserted.
4, a welding gun 66 attached to a pair of rods 64 erected, a chuck 68 for holding the head of a stud 80 provided at the lower end of the welding gun 66; and a handle 70 having a welding switch 69 provided at the welding switch 69. Furthermore, an arc shield holding part 72 is detachably attached to the lower end of each of the levers 50, and each arc shield holding part 72 holds the arc shield divided body 30, respectively.

The arc shield holding section 72 is shown in FIG.
As shown in 5, it comprises a holding part main body 74 and a clamping body 76. The holding portion main body 74 is formed by a stepped portion 50a of the lever 50 and a nut 50b screwed onto the lower end of the lever 50.
It is attached to the lever 50. Further, a convex portion 74c formed on the inner surface 74a of the arc shield holding body is fitted into the concave portion 38 of the arc shield divided body, and a screw 76a is screwed onto the upper end surface 30a of the arc shield holding body. A clamping body 76 fixed to 74
is arranged, and the arc shield division body 30 is
The upper surface 38 of the concave portion is formed by the convex portion 74c and the clamping body 76.
a and the upper end surface 30a are vertically sandwiched and held by the arc shield holding portion 72.

Arc stud welding by the welding machine 42 is performed as follows. First, the handle 58 is rotated upward from the position shown by the solid line in FIG. 2 to the position shown by the broken line. Then, the link 56 tilts, the joint pin 54 moves downward in the elongated hole 60, the joint pin 52 rotates around the fulcrum pin 48, and the two levers 50 open, as shown by broken lines. It becomes open. After that, the chuck 68 is made to grip the head of the stud 80,
The handle 58 is rotated downward to close both levers 50 to the closed state shown by the solid line. In this closed state,
Arc shield holding part 7 provided on each lever 50
2 are brought into contact with each other, and the arc shield divided bodies 30 are also brought into contact with each other facing each other to form a cylindrical arc shield, and the stud 80 is fitted into this arc shield. Next, from this state, the welding machine 42 is lowered to bring the lower end of the stud 80 and the lower end surface of the arc shield divided body 30 into contact with a predetermined position of the workpiece 82, and the switch 69 is pressed to perform welding. . After welding is completed, the handle 58 is rotated upward to open the lever 50, and arc stud welding is repeated in the same manner.

By the way, the arc shield divided body 30
is made of ceramics containing alumina (Al2O3). Alumina has strong chemical bonds and therefore has extremely high chemical and physical stability, and also has a relatively high melting point of 2050° C. and excellent heat resistance.

The arc shield segment 30 made of ceramic containing alumina has the characteristics of alumina described above, and therefore has extremely high physical and chemical stability, and has extremely excellent corrosion resistance, especially against molten metal. In addition, the melting point is 2050°C, which is more than the general welding temperature of 1300°C or higher, so there is little material deterioration due to high temperatures during welding, and in this sense it has sufficient heat resistance. .

Therefore, the arc shield divided body 30 has heat resistance and particularly excellent corrosion resistance, and even if it is used repeatedly, there is little deterioration of the material, and the inner surface of the arc shield divided body is not damaged by molten metal. It has very little corrosion and can be used suitably in cases where it is used repeatedly and particularly high corrosion resistance is required.

[0023] It is preferable that the above-mentioned alumina is contained in an amount of 30% by weight or more. This is because when the content is 30% by weight or more, the characteristics of alumina can be exhibited to some extent in the ceramic, and when it is less than 30% by weight, the characteristics of alumina are not exhibited very much. In this sense, it is more preferable that the alumina is contained in an amount of 50% by weight or more, and it is even more preferable that the alumina is contained as a main component (the component with the highest content).

The welding auxiliary material made of ceramics containing alumina according to the present invention can be used not only for the above-mentioned arc shield, but also for various other welding auxiliary materials, such as welding auxiliary materials (tabs) in joint arc welding between plates. It can also be applied as a welding auxiliary material (covering material) for joint welding of steel bars and steel bars.

FIG. 6 is a perspective view showing joint arc welding between plates when the present invention is applied to the above-mentioned tab.
0 and the plate 92 are arc welded at a welding portion 94, and tabs 96 made of ceramic containing alumina are provided at both ends of the welding portion 94. The tab 96 may be disposed using a strong permanent magnet, such as a rare earth permanent magnet, or mechanical screw fastening.

FIG. 7 is a front view showing joint welding (enclose welding) between steel bars when the present invention is applied to the above-mentioned backing material, and FIG. 8 is a sectional view taken along the line VIII-VIII of FIG. and the steel bar 100 are arranged with their end faces facing each other, and a backing member 102 having a U-shaped cross section made of the alumina-containing ceramic is arranged at the opposing end faces, and a metal presser is provided on the outside of the member 102. Jig 104
are arranged, and under such conditions both end faces of the steel bar are welded by gas welding using a welding rod 106.

[0027] Also in the case of the tab 90 and the backing material 102,
Since it is made of ceramic containing alumina, it has heat resistance and excellent corrosion resistance, similar to the case of the arc shield segment 30 described above.

[0028]

Effects of the Invention The welding auxiliary material according to the present invention is made of ceramic containing alumina as described above, and therefore has the characteristics of alumina, that is, heat resistance, and particularly has excellent corrosion resistance against molten metal. Therefore, it can be suitably used when it is used repeatedly and particularly high corrosion resistance is required.

[Brief explanation of drawings]

[Fig. 1] A perspective view showing an embodiment of the present invention.

[Fig. 2] Front view of an arc stud welding machine using the embodiment shown in Fig. 1.

[Figure 3] Right side view of the arc stud welding machine shown in Figure 2

[
Figure 4: IV-IV line arrow view in Figure 2

[Figure 5] Cross-sectional view taken along the line V-V in Figure 4

[Fig. 6] Perspective view showing another embodiment

[Fig. 7] Front view showing still another embodiment

[Figure 8] VIII-VIII line cross-sectional view in Figure 7

[Figure 9] Diagram explaining arc stud welding using an arc shield

[Explanation of symbols]

Claims (1)

[Claims] 1. A welding aid comprising a ceramic containing alumina.