JP2678226B2 - Welding ceramic piece - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic piece for welding which is attached to the surface of a metal base material by arc stud welding. More specifically, it is used as a heat-resistant material for structures used in high temperature atmosphere such as furnace walls and burners. Alternatively, the present invention relates to a ceramic piece for welding suitable for use as a wear-resistant material for high-speed rotating equipment such as blowers and pumps.

[0002]

2. Description of the Related Art As conventional ceramic pieces for welding, those described in JP-A-63-171272 can be mentioned. As shown in FIG. 4A, the ceramic piece for welding includes a ceramic piece body 51 and a metal stud 59. First, the ceramic piece main body 51 has a concave
Is formed, and a hole 57 penetrating through the concave portion 54 on the front surface 52 side is formed. Also stud 5
Reference numeral 9 denotes a cone portion 61 having a projection 60 at its tip, a flange portion 62 following the cone portion 61, and a welding current supply pin portion 65 erected at the center of the upper surface 63 of the flange portion 62. Made up of Then, by inserting the pin portion 65 into the hole portion 57 and brazing the upper surface 63 of the flange portion 62 and the bottom surface 55 of the concave portion 54, the ceramic piece body 51 and the stud 59 are joined and integrated, and welding is performed. Forming ceramic pieces for use. This ceramic piece for welding is attached to the base material 71
This is performed by holding the holder portion 66 of the pin portion 65 with a holder of a welding machine, supplying a welding current while making the projection 60 contact the surface 72 of the base material 71, and performing arc stud welding of the stud 59 to the base material 71. . After this welding, as shown in FIG.
The hole 57 cut out from FIG. 7 and having a cavity is filled with a filler 74.

[0003]

However, since the coefficient of thermal expansion of the ceramic piece body 51 and the stud 59 in the above-mentioned welding ceramic piece is generally different, the brazing portion which is the joint surface between the ceramic piece body 51 and the stud 59 has a different thermal expansion coefficient. However, shearing force is generated during brazing and during use. This shearing force induces the occurrence of cracks in the vicinity of the brazed portion of the ceramic piece body 51 having poor ductility, and causes the ceramic piece body 51 to peel off.

In order to avoid the peeling of the ceramic piece body 51, the stud 59 made of a material having a thermal expansion coefficient close to that of the ceramic piece body 51 should be selected in consideration of the conditions such as the brazing temperature and the operating temperature. I have to.
For example, when alumina is used for the ceramic piece body 51, it is said that it is preferable to use kovar as the stud 59. However, this is inexpensive kovar, has a coefficient of thermal expansion close to that of alumina, and is easy to weld. Because it is a metal. But even with this Kovar,
It has a coefficient of thermal expansion close to that of alumina up to around 600 ° C., and at higher temperatures, internal stress is unavoidable at the joint surface.

As described above, in the conventional case, the stud 5 has a relationship with the coefficient of thermal expansion of the ceramic piece body 51.
There is a problem that the material of No. 9 is limited, and the operating temperature of the ceramic piece for welding itself is also limited by the coefficient of thermal expansion of both of them.

The present invention has been made in order to solve the above-mentioned conventional drawbacks, and its object is for welding in which the ceramic piece body and the stud are not restricted in material and cracking is unlikely to occur in the ceramic piece body. To provide a ceramic piece.

[0007]

Therefore, the ceramic piece for welding according to claim 1 is a ceramic piece for welding comprising the ceramic piece body 1 and a stud 9, and the stud 9 is a flange provided with a cone portion 17. A welding in which a pin portion 10 is erected on the portion 13 and the pin portion 10 is inserted into a hole 7 formed through the ceramic piece body 1 so that the cone portion 17 is arc stud welded to the base material 21. In the ceramic piece for use, the hole portion 7 is provided on the surface 2 side of the ceramic piece body 1.
A concave portion 4a communicating with the concave portion 4a is formed, and the flat plate-shaped fixing members 26 and 31 are housed in the concave portion 4a.
31 and the pin portion 10 are joined, and the fixing members 26, 31
On a ceramic body 1 between the flange portion 13 and the
It is characterized in that the pin portion 10 is compressed and held only in the axial direction .

In the ceramic piece for welding according to the second aspect of the present invention, the coefficient of thermal expansion of the pin portion 10 is made larger than that of the ceramic piece body 1, and the fixing members 26, 31 and the pin portion 10 are heated. It is characterized by doing in.

[0009]

In the ceramic piece for welding according to the above-mentioned claim 1, the ceramic piece body 1 and the stud 9 are integrated with each other without directly brazing the ceramic piece body 1 and the flange portion 13 of the stud 9 to each other. Since the pin portion 10 and the fixing members 26 and 31 are joined so that the ceramics piece body 1 is sandwiched and held by the flange portion 13 of 9 and the fixing members 26 and 31, heat of the flange portion 13 in the lateral direction is increased. Expansion and contraction are not easily restrained by the ceramic piece body 1. Therefore, it is possible to suppress the generation of internal stress in the ceramic piece body 1. Also ceramic
Axial compressive force acts on the x-piece body 1.
Since it does not apply tensile force, it is aimed at impact resistance.
I can do it.

Further, in the ceramic piece for welding according to claim 2, since the coefficient of thermal expansion of the pin portion 10 is larger than that of the ceramic piece body 1, the ceramic piece body 1
Is constantly pinched between the flange portion 13 and the fixing members 26 and 31 due to contraction in the axial direction due to cooling of the pin portion 10. Therefore, the ceramic piece body 1 and the stud 9
There is no looseness.

[0011]

Next, specific examples of the ceramic piece for welding according to the present invention will be described in detail with reference to the drawings. FIG. 1A is a longitudinal sectional view showing a first embodiment of the present invention. In the figure, 1 is a ceramic piece body, and the material thereof is alumina, zirconia, silicon carbide, silicon nitride or the like having excellent heat resistance and wear resistance, and a square or rectangular shape having a thickness of 3 mm to 25 mm. It is obtained by molding and sintering into a plate shape. The ceramic piece body 1 has recesses 4a and 4b formed on the front surface 2 and the back surface 3, respectively. The bottom surface 5a of the recess 4a on the front surface 2 side communicates with the bottom surface 5b of the recess 4b on the back surface 3 side by a hole 7 formed substantially in the center thereof.

Reference numeral 9 denotes a stud, the material of which is a metal such as stainless steel or copper, which is determined in consideration of the weldability with the metal base material and the coefficient of thermal expansion. The stud 9 is composed of a pin portion 10, a flange portion 13, and a cone portion 17. First, the pin portion 10 is inserted into the hole portion 7, one end side of which has a holder portion 11 which projects outward from the surface 2 of the ceramic piece body 1, and the other end side of which is at the center of the upper surface 14 of the flange portion 13. It is joined. The pin portion 10 may be formed integrally with the projection 16, the cone portion 17, and the flange portion 13 or may be formed separately from these.

In the flange portion 13, a cone portion 17 having a projection 16 on the side opposite to the upper surface 14 thereof is bulged and is housed in the recess 4b on the back surface 3 side.
Is in contact with the bottom surface 5b. The shape of the flange portion 13 is
It has a shape corresponding to the shape of the recessed portion 4b to be stored.

In FIG. 31, a through hole 34 is formed at the center thereof.
It is a flat plate-shaped fixing ring. The pin portion 10 of the fixing ring 31 is inserted into the through hole 34 and is housed in the recess 4 a on the surface 2 side. Further, the lower surface 33 is brought into contact with the bottom surface 5a, and is fixed by brazing to the pin portion 10 at the through hole 34 portion. When brazing the both, the ceramic piece body 1 is inevitably heated. However, when these are cooled, generally, the stud 9 has a higher thermal expansion coefficient than the ceramic piece body 1. Therefore, the ceramic piece body 1 is compressed by the flange portion 13 and the fixing ring 31 and receives a compressive force. Moreover, since the operating temperature of the ceramic piece is usually set lower than the brazing temperature, the ceramic piece body 1 and the stud 9 are not used.
It does not loosen during use and is stronger than mechanical bond against repeated thermal shock. As described above, by this brazing, the flange portion 13 and the fixing ring 3 are
1 and the ceramic piece body 1 are sandwiched between them, and the ceramic piece body 1 and the stud 9 are integrated.

In order to weld the ceramic piece for welding having the above structure to the metal base material, first, the holder portion 11 is held by the holder of the welding machine, the projection 16 is pressed against the surface of the metal base material, and a welding current is applied. And generate an arc. By this arc, the cone portion 17 and the surface of the metal base material are melted and welded by a pressing force.

In this embodiment, unlike the conventional example, the bottom surface 5b of the back side recess 4b and the top surface 14 of the flange portion 13 are not brazed but are in surface contact with each other. Due to heat and heating during use, both expand in the lateral direction, and even if there is a difference in the amount of expansion, one does not restrain the other, thereby suppressing the generation of internal stress, and a ceramic with poor ductility. Peace body 1
Cracks can be prevented from occurring. Also, ceramics
Only a compressive force acts on the base body 1, and
Since the tensile force does not act, impact resistance can be improved.
It is possible to prevent the occurrence of cracks. It should be noted that FIG. 1B shows a modified example, which is the fixing ring 31.
Is thinly formed, and the upper portion thereof is covered with a filler 26 in which an abrasion resistant material (for example, tungsten carbide) is mixed in a brazing material (for example, nickel braze: BNi-2 of JISZ3265) to improve abrasion resistance. It was
It is also possible to carry out in such a mode.

FIG. 2 is a vertical sectional view showing a second embodiment of the present invention. In the second embodiment, instead of the fixing ring 31, a wear-resistant material (for example, tungsten carbide) is used as a brazing material (for example, nickel brazing: BN of JIS Z3265).
i-2) The filler (fixing member) 26 mixed in is flat
Are Takashi愼to. That is, as shown in FIG. 2, the filling material 26 is filled in the concave portion 4a and sintered to fix the pin portion 10, thereby holding the ceramic piece body 1 in a pinching state in cooperation with the flange portion 13. There is.

FIG. 3 is a longitudinal sectional view showing a third embodiment of the present invention, FIG. 3 (a) shows a state before stud welding to a member to be welded, and FIG. 3 (b) shows a state after welding. Are shown respectively. In the third embodiment, as in the first embodiment, the fixing ring 31 is housed in the recess 4a, and the through hole 34 is formed.
The pin portion 10 is brazed and fixed at the portion, but the thickness of the fixing ring 31 is thinner than the depth of the recess 4a. After the stud 9 is welded to the metal base material 21, the pin 10 outside the upper surface 32 of the fixing ring 31 is notched with the notch 1.
Cut off from 2. Further, the fixing ring 31 in the recess 4a is filled with the resin 27 mixed with the ceramic so that the cut portion of the pin portion 10 is not exposed without lowering the bonding strength with the pin portion 10. There is. Thereby, for example, the pin portion 10 is immersed in the high temperature molten metal.
Can be prevented from being eluted and contaminating the molten metal.

In the arc stud welding, a gap 24 is inevitably required between the back surface 3 of the ceramic piece body 1 and the front surface 22 of the metal base material 21 in order to ensure reliable welding. However, since the gap 24 exists, that is, because the ceramic piece body 1 and the metal base material 21 are not in surface contact with each other, the ceramic piece body 1 is bent due to, for example, an impact, or the corrosive fluid gap 24 However, there is a problem that the stud 9 and the metal base material 21 are melted and damaged by the infiltration. Therefore, in this embodiment,
The elastic material 18 is connected to the ceramic piece body 1 and the metal base material 21.
The ceramic piece body 1 and the metal base material 21 are brought into surface contact with each other to prevent bending and intrusion of corrosive fluid.

[0020]

As described above, in the ceramic piece for welding according to claim 1, the ceramic piece body and the stud are not directly joined by a joining means such as brazing, but the ceramic piece body is joined to the flange portion of the stud and the fixing member. Since it is sandwiched between the ceramic piece body and the stud, the material of the ceramic piece body and the stud is not restricted as in the past, and moreover, the generation of shearing force on the contact surface between them is suppressed and cracks occur in the ceramic piece body. It can be prevented. Also ceramics
Only compression force acts on the body of the piece,
Since the tensile force does not act, impact resistance can be improved.
It is possible to prevent the occurrence of cracks.

According to the second aspect of the present invention, the flange portion and the fixing member constantly press the ceramic piece body, and the ceramic piece body and the stud are not loosened.

[Brief description of the drawings]

1A and 1B are views showing a first embodiment of a ceramic piece for welding according to the present invention, in which FIG. 1A is a vertical sectional view showing a case where a fixing ring is used as a fixing member, and FIG. It is a figure.

FIG. 2 is a view showing a second embodiment of the present invention and is a vertical sectional view showing a case where a filler is used as a fixing member.

3A and 3B are views showing a third embodiment of the present invention, in which FIG. 3A is a vertical sectional view showing a state before welding, and FIG. 3B is a vertical sectional view showing a state after welding.

4A and 4B are views showing a conventional example, in which FIG. 4A is a longitudinal sectional view showing a state before welding, and FIG. 4B is a longitudinal sectional view showing a state after welding.

[Explanation of symbols]

 1 Ceramics piece main body 2 Front surface 3 Back surface 4a Recessed portion 5a Bottom surface 7 Hole portion 9 Stud 10 Pin portion 13 Flange portion 17 Cone portion 21 Base material 26 Fixing member 31 Fixing member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-63-171272 (JP, A) Actually opened 63-111280 (JP, U) Actually opened 58-143095 (JP, U)

Claims (2)

(57) [Claims] 1. A ceramic piece for welding comprising a ceramic piece body (1) and a stud (9), wherein the stud (9) has a pin portion on a flange portion (13) having a cone portion (17). (10) is erected, and the pin portion (10) is inserted into a hole portion (7) penetratingly formed in the ceramic piece body (1).
In a ceramic piece for welding configured to arc-stud weld 7) to a base material (21), the hole (7) is provided on the surface (2) side of the ceramic piece body (1).
Forming a recess (4a) communicating with the recess (4a)
While accommodating the flat plate-shaped fixing members (26) (31),
Fixing members (26) (31) and pin portion (10) joining the said pin portion of the ceramic body (1) between the fixing member (26) (31) and the flange (13)
(10) A ceramic piece for welding, characterized in that it is compressed and held only in the axial direction . 2. The coefficient of thermal expansion of the pin portion (10) is made larger than that of the ceramic piece body (1), and the fixing member (26) (31) and the pin portion (10) are heated to each other. 2. The ceramic piece for welding according to claim 1, wherein