JPS60201002A - turbine rotor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a turbine rotor having a structure in which a ceramic turbine rotor body such as 813N4.810 or Sialon, used in turbochargers, gas turbines, etc., is joined to a metal shaft. In particular, this invention relates to improvements when the bearing part is made of metal.

(Conventional technology) In the case of metal rotors, SCM is conventionally used as the shaft.

Strong steel such as SNCM or SAOM is used, and before or after welding with the rotor, it is tempered by quenching and tempering to adjust the core hardness and increase the axial strength. The surface of the bearing part was hardened by quenching to create a thin, strong shaft that could withstand sliding.

On the other hand, when joining a ceramic rotor and metal,
Firing or brazing is used.

However, when joining is carried out on the rotor side close to the bearing, the shaft becomes dull with conventional steel materials due to the heating during joining, and the hardness is less than My250 at the center, reducing the strength of the shaft. There was a problem. In addition, if you try to increase the hardness again after joining, there are problems such as the once joined part coming off during the tempering quenching process, and ceramic bonding due to internal stress caused by rapid thermal distortion after quenching. was there. Even in the case of surface hardening of the shaft bearing, this type of hardening method could not be used. Therefore, the appearance of a metal shaft with increased hardness of the bearing portion has been awaited.

(Structure of the Invention) The present invention satisfies the condition that the hardness of the shaft of a turbine rotor such as a turbocharger (at least the shaft on the rotor body side (two parts) has a hardness of HV 250 or more at the center). , Hv500 can be achieved when necessary in terms of wear resistance, and it solves the above-mentioned problem regarding shaft damage. The purpose of the present invention is to provide a ceramic turbine rotor in which the shaft is less likely to be damaged by using a metal material having a hardness of Hv 250 or more after joining without quenching or tempering.

Examples of metals that satisfy the above conditions include stellite,
Items with intrinsic hardness such as tungsten, items with increased hardness due to precipitation hardening such as Inconel and Nimonik, and items with increased hardness due to two-age hardening, such as maraging steel. Ashi, either is fine.

In the case of tungsten, its own thermal expansion is small, and S
When bonding with low expansion ceramics such as i3N4.5iCi, residual stress is small, which is advantageous. In addition, in the case of precipitation hardened metals, if the precipitation temperature is lower than the brazing temperature, a predetermined hardness can be obtained by holding the metal at the precipitation temperature during cooling after brazing, or by slightly heating it after cooling. or,
When using maraging steel, hardness can be increased using a similar method.

(Embodiments) Next, embodiments of the present invention will be described below with reference to the drawings.

Example 1: As shown in FIG.
-T1(o,1p)-MO(0,1tt J-Ou(
2tt), a shaft 3 made of 80M material is coated on the tungsten shaft 2a and other parts on the rotor body side.
Brazing 4 was performed at 850° C. between the inner surface of the rotor 1, the surface of the shaft, and the end surface of the shaft. The joint between the shafts was located 10 degrees away from the second shaft bearing part in consideration of the heat treatment to be performed later. The hardness of the tungsten shaft 2a after brazing is H
There was v390'u. Next, the shaft 3a made of 80M material was subjected to induction hardening to make it HV 500, finished to the specified dimensions, and incorporated as a turbocharger.
A spin test of 000 r, p, m, and 200 hr was conducted, and the wear of the tungsten shaft 2a was less than 0.5 μ, and there was no damage.

Example 2: As shown in FIG. 2, the bonding surface of a turbocharger rotor 1 made of Si3N4 (Tt(a, 1A)-MO(0,1μ)-0u(2μ) by two physical vapor deposition methods)
), and then the Inconel shaft 2b was brazed to the rotor body with a copper buffer plate 5 of 1 silk thick sandwiched between them.The hardness of the Inconel shaft 2b was Hv 4 o o. Further, the shaft 3 made of 80M material which had been hardened and tempered was friction welded to the end face 6aL, and the surface of the shaft 3a made of 6CM$J was surface hardened. Then, it was finished to the specified dimensions to 150.00 Or, p, IIl.

When a 20 Q hr spin test was conducted, the wear of Inconel 713C was less than 0.5μ and no damage occurred.

Embodiment 3: As shown in FIG.
i(0,I II )-Mo(0,I It )-au
After coating (2It), 113Ni-9Co was sandwiched between Kovar buffer plates 4 with a thickness of 0.5HM.
-0,4Ti -0,06A/A shaft 2C made of maraging steel was brazed with silver solder at 1000°C, and after air cooling, aging treatment was performed at 450°C. As a result, the hardness of the shaft 2C made of simul-aging steel was 520 Hv.

Next, shaft 3 made of 8NCM hardened and tempered
After electron beam bonding 6b between b and end face, SNC! M
Only the shaft 3b made of material is surface hardened and finished to the specified dimensions, 150.00 Or, Lm, 2. Mouth Qhr
When a spin test was conducted, there was almost no wear on the maraging steel shaft, and good joining results were obtained with no damage.

In each of the above embodiments, the high hardness material 2a+2b or 2C is used only on the rotor body side for the bearing part of the metal shaft, but as shown in FIG. Of course, the entire body may be constructed of the above-mentioned hardness material.

Regarding the joining means, each embodiment has been described only in the case of brazing, but in the case of sintering or a combination of brazing and sintering, the shaft is heated to 60D°C or higher during joining. The same can be done just by generating the essence.

(Effects of the Invention) As described above, the present invention has been developed by quenching the ΦJ1 bearing part, especially the shaft part on the rotor body side, which is a problem in terms of the strength of the shaft of the vocharger, to a hardness of H'v 250 or more (after joining). Since we use metal feed obtained without tempering,
It is possible to provide a ceramic rotor whose shaft is extremely less likely to be damaged.

[Brief explanation of drawings]

1 to 4 are partially cut-away simplified explanatory views showing a thirteenth embodiment of the present invention. l: Turbocharger rotor 2a made of Si3N
: Tungsten shaft 2b: Inconel shaft 2C: I/mount 3a made of maraging steel: i3CM
Middle ib 3 b consisting of 4J: Shaft 4 consisting of SNCM shrine: Brazing 5: Buffer plate 6a Friction welding 61), Electron beam bonding agent Patent attorney Mamoru Takeuchi (Figure 1, Figure 2) Figure 3 Figure 4

Claims (3)

[Claims] (1) In a turbine rotor in which a metal shaft is bonded to a ceramic turbine rotor body, the hardness of at least the shaft bearing on the rotor body side as the metal shaft after bonding is Hv250 or more without quenching or tempering. A turbine rotor characterized by using a metal material having (2) The turbine rotor according to claim 1, wherein the ceramic turbine rotor body and the metal shaft are joined by brazing. (3) The turbine rotor according to claim 1, wherein the metal material is an age hardening metal. (3) The turbine rotor according to claim 1, wherein the metal material is a precipitation hardening metal.