JPH09225572A - Production of welding ring of difficultly processable alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a welding ring of difficultly processable alloy on which the tensile strength and elongation of the welding part is made as same as the tensile strength and elongation of a base material by hot ring rolling after bending a rod blank of difficultly processable alloy in a ring like and welding both ends. SOLUTION: An alloy of difficultly processable material used in the production of a welding ring is a Ni base alloy, a Ti alloy and a high alloy steel, etc., as the super alloy. In ring rolling executed in the production of a ring, a ring blank 5 as the difficultly processable subject is hung on a mandrel 2 of freely rotating and it is rolled with a ring roll 3 and the mandrel 2 while heating the ring blank with a high frequency heating device 4. The temperature of ring rolling is made preferably, for example, 900 to 1100 deg.C in the super alloy, 600 to 980 deg.C in the Ti alloy and 600 to 1000 deg.C in the high alloy steel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a weld ring made of a hard-to-work alloy such as superalloy or high alloy steel.

[0002]

2. Description of the Related Art Conventionally, when a ring used for aircraft parts is manufactured by welding a difficult-to-process alloy such as a superalloy (Ni alloy), a Ti alloy, or a high alloy steel, a rod-shaped material is bent into an annular shape, and both ends are bent. Were joined by flash butt welding, friction welding, etc., and then the joints were deburred, and finishing processing such as straightening by rolling was performed. However, the ring thus manufactured has a drawback that the tensile strength and elongation of the welded portion are lower than the tensile strength and elongation of the base material portion.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a weld made of a difficult-to-machine alloy material such as a superalloy, a Ti alloy, or a high alloy steel in which the tensile strength and elongation of the welded portion are the same as those of the base metal portion. It is intended to provide a method of manufacturing a ring.

[0004]

In order to achieve the above object, in the method for manufacturing a difficult-to-machine alloy welding ring of the present invention, a bar-shaped material made of a difficult-to-process alloy is bent into an annular shape, and both ends are welded and joined. After that, it is hot ring rolling.

Difficult-to-machine alloy materials used in the method for manufacturing the weld ring of the present invention are superalloys such as Ni-base alloys, Ti alloys, and high-alloy steels, and the Ni-base alloys are Nimonic 80A,
There are various types of Inconel, various types of Monel, various Hastelloy, and the Ti alloys are 6Al-4V-Ti and 8Al-1Mo.
-1V-Ti, etc., and the high alloy steel is SUS30.
4, austenitic heat resistant steels such as SUS321 and SUH660, and high Cr ferritic heat resistant steels such as SUS430.

Further, the welding method in the present invention may be any welding method such as flash butt welding or friction welding as long as the both ends can be butt-welded together. In the ring roll processing performed in the method for manufacturing a weld ring of the present invention, as shown in FIG. 1, a rotatable mandrel (2) is hung on a ring material (5) which is a workpiece, and the ring material ( It can be carried out by a device for rolling 5) with a ring roll (3) and a mandrel (2) while heating it with a high-frequency heating device (4).

The temperature of this ring roll processing is the hot working temperature usually performed, for example, 900 to 1100 for superalloys.
Ti alloy is 600 to 980 ° C, and high alloy steel is 600 to 980 ° C.
It may be 1000 ° C. Further, the working rate of hot working must be 30% or more.

According to the present invention, by performing hot ring roll processing after welding, it is possible to refine crystal grains, impurities, etc. coarsened by welding, and press-bond voids such as bubbles generated in welding. Because you can do things,
It is speculated that the strength and elongation of the welded portion will increase, resulting in higher welded joint efficiency.

[0009]

Embodiments of the present invention will be described below. Example 1 Cross section is 40 mm (thickness) × 50 mm (width), length 122
0 mm SUS304 (C: 0.04%, Si: 0.5
5%, Mn: 0.98%, P: 0.02%, S: 0.0
17%, Ni: 9.83%, Cr: 19.5%, the remainder being substantially Fe) was bent into a ring shape, and both ends of this were flash-butt welded by a usual method to produce a ring having an inner diameter of 370 mm. After removing the burrs from this ring, hot working was performed using a ring roll processing device as shown in FIG. 1 to obtain a cross section of 20 mm (thickness) × 50 mm (width) and an inner diameter of 80.
A 0 mm ring was manufactured, and then heat-treated (ST) in which it was heated at 1050 ° C. for 30 minutes and then cooled with water. A tensile test was carried out using a tensile test piece cut out from this ring so that the welded part was at the center and a tensile test piece cut out from the part (base material) not containing the welded part. The result was as described in the column of Example 1.

Conventional Example 1 A cross section having the same composition as in Example 1 has a cross section of 20 mm (thickness) × 5.
SUS304 having a length of 0 mm (width) and a length of 2580 mm is bent into a ring shape, and both ends of the SUS304 are subjected to flash butt welding by a normal method to have a cross section of 20 mm (thickness) × 50 mm (width),
A ring having an inner diameter of 800 mm was manufactured, and then heat-treated (ST) in which it was heated at 1050 ° C. for 30 minutes and then cooled with water. When a tensile test was performed using a tensile test piece cut out from this ring in the same manner as in Example 1, the results shown in the column of Conventional Example 1 in Table 1 were obtained. The joint efficiencies in Tables 1 and 2 are expressed by the following formula: tensile strength (elongation) of welded portion / tensile strength (elongation) of base material × 100 (%).

[0011]

[Table 1]

In the welded portion of the ring according to the first embodiment of the present invention, 0.
It can be seen that all of the 2% proof stress, the tensile strength, the elongation, the drawing and the joint efficiency are higher than those of the welded portion of the ring of Conventional Example 1.

Example 2 A cross section of 40 mm (thickness) × 50 mm (width) and a length of 123
0 mm Inconel 718 (C: 0.043%, Mn:
0.12%, Fe: 18.2%, Si: 0.14%, C
r: 18.83%, Al: 0.52%, Ti: 1.06
%, Mo: 3.31%, the remainder being substantially Ni) was bent into a ring, and both ends of this were flash-butt welded in the same manner as in Example 1 to produce a ring having an inner diameter of 370 mm. After removing the burrs from this ring, hot working was performed using a ring roll processing device as shown in FIG. 1, and the cross section was 20 mm (thickness) × 50 mm (width) and the inner diameter was 800 m.
m rings were produced. After that, it is heated at 954 ° C. for 1 hour and then water-cooled (ST), further heated at 718 ° C. for 8 hours, and then cooled to 621 ° C. at a cooling rate of 55 ° C./hour.
A heat treatment (AG) was performed in which the temperature was kept at 8 ° C. for 8 hours and then air cooling was performed. A tensile test piece was produced from this ring in the same manner as in Example 1, and a tensile test was performed using this test piece. The results shown in the column of Example 2 in Table 2 were obtained.

Conventional Example 2 A cross section having the same composition as in Example 2 has a cross section of 20 mm (thickness) × 5.
Inconel 718 having a length of 0 mm (width) and a length of 2595 mm is bent into a ring shape, and both ends of the Inconel 718 are flash butt welded by a normal method to obtain a cross section of 20 mm (thickness) x 50 mm.
A ring having a width of 800 mm and an inner diameter of 800 mm was manufactured, and then the same heat treatment as in Example 2 was performed. A tensile test piece was manufactured from this ring in the same manner as in Example 1, and a tensile test was performed using this test piece, and the results shown in the column of Conventional Example 2 in Table 2 were obtained.

[0015]

[Table 2]

In the weld portion of the ring according to the second embodiment of the present invention,
It can be seen that the 2% proof stress, the tensile strength, the elongation, the drawing and the joint efficiency are all higher than those of the welded portion of the ring of Conventional Example 2.

The above embodiment was carried out with SUS304 and Inconel 718, but it can also be carried out with other hard-to-machine alloy materials such as other Ni alloys, Ti alloys and other high alloy steels. . Furthermore, although the above-mentioned embodiment is an example using flash butt welding, it can be manufactured by another welding method such as friction welding in the same manner.

[0018]

According to the present invention, the above-described configuration enables
It has an excellent effect that the tensile strength and elongation of the welded portion become equivalent to the tensile strength and elongation of the base material portion.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an outline of a ring roll processing apparatus used in a method for manufacturing a weld ring according to the present invention and a method for performing ring roll processing using this apparatus.

[Brief description of reference numerals]

 1 Ring roll processing device 2 Mandrel 3 Ring roll 4 High frequency heating device 5 Ring material of work piece

Claims (1)

[Claims] 1. A method for manufacturing a welded ring made of a hard-to-work alloy, which comprises bending a rod-shaped material of a hard-to-work alloy into an annular shape, welding both ends to join them, and then hot ring rolling.