JPS61111745A - Production of corrosion-and wear-resistant coating material - Google Patents

Abstract

PURPOSE:To obtain a material excellent as a corrosion- and wear-resistant coating material for a member for high-temp. service by producing a thin composite sheet with a heat resistant brazing filler metal by a quick cooling and a solidifying method while adding short ceramic fiber to the down flow melt, etc. of a corrosion- and wear- resistant Co alloy. CONSTITUTION:The brazing filler metal 2 melted in a crucible 1 is continuously dropped or injected onto one roll 3 out of two rolls 3. the corrosion- and wear-resistant Co alloy (e.g.; stellite alloy) 12 melted in the other crucible 11 is further dropped or injected to the spacing between a pair of the roll 3. The short ceramic fibers are at the same instant supplied by a gaseous pressure into the molten Co alloy pool in the spacing between a pair of the rolls 3 from a supply cylinder 4 for said fibers. The molten alloy is quickly cooled by the rolls 3 immediately thereafter by which a thin sheet 5 is obtd. The sheet 5 is adhered and fixed via the brazing filler metal layer 7 to the required point of the member for high-temp. service and is then joined by brazing in a vacuum or reducing atmosphere, by which the intended corrosion- and wear-resistant coating material 15 is obtd. In the figure, 6 denotes the corrosion- resistant Co alloys dispersed with the short ceramic fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing a corrosion-resistant and wear-resistant coating material for high-temperature members, which has improved durability compared to conventional methods.

(Prior art) In order to improve the corrosion resistance of high-temperature parts such as gas turbines and steam turbine rotor blades, conventional methods... lll
The following methods have been implemented.

(1) Weld overlay coating with Co-based wear-resistant material such as stellite alloy.

+21 Braze plates of Co-based alloy, etc.

(31 Ceramics such as TiN and TiC are coated on the surface of the material by vapor deposition or the like.

However, these methods have the following drawbacks.

(1) Welding overlay method Wear-resistant alloys such as stellite alloys generally have low thermal conductivity;
If the coating layer is thick, the surface temperature will rise, making it more likely to cause thermal fatigue and fatigue, so it is desirable that the coating layer be thin.
In the case of bath welding, the coating layer cannot be made thinner due to reasons such as melt penetration with the base metal. In addition, because the crystal grains in the weld are large,
Thermal fatigue cracks develop quickly, and cracks easily occur due to heat shrinkage after welding.

(2) Method of joining thin plates by brazing Co-based alloys have high hardness and low toughness, making it difficult to process thin plates. Furthermore, since the heat-resistant brazing material used for joining has low high-temperature strength, the coating layer is likely to peel off due to thermal fatigue.

(3) Method of coating ceramics The thickness of the ceramic coating that can be formed by vapor deposition, etc. is 1 to 2 μm, and if it is this thick, it will not erode during use and will wear out in a short time. Because of this, the durability of the coating layer is poor.

(Problems to be Solved by the Invention) The present invention solves the drawbacks of the conventional methods described above, and provides a method for producing a highly durable material that has excellent performance as a corrosion-resistant and wear-resistant coating material for high-temperature components. The purpose is to provide

(Means for solving the problem) The present inventors have developed a composite thin plate of a C0-based corrosion-resistant and wear-resistant alloy, which was difficult to process using conventional methods, and a filler metal, which generally has poor toughness, by rapid solidification, and the erosion resistance of such a thin plate. In order to improve this, we came up with the idea of mixing ceramic short fibers into a Co-based alloy, and arrived at the present invention.

That is, the present invention is a corrosion-resistant alloy characterized by manufacturing a composite thin plate with a heat-resistant brazing filler metal by a rapid solidification method while adding ceramic short fibers into the dripping stream or jet stream of a CO-based corrosion-resistant and wear-resistant alloy bath water. A method of manufacturing a wear-resistant coating material is provided.

In the production of CO-based corrosion-resistant and wear-resistant alloys and heat-resistant brazing filler metals by the rapid solidification method, the materials are melted in a bath using high-frequency melting, for example, and then passed through a nozzle at the bottom of a melting crucible onto the space between two rotating rolls or onto the surface of a single rotating roll. A bath-melted CO-based alloy is injected and rapidly solidified on the roll surface to form a thin plate.

The 00 group corrosion-resistant and wear-resistant alloy used in the present invention is preferably, for example, a stellite alloy, and the heat-resistant brazing material is, for example, J-5BNi-1, IA, 2°5, 4.5.6.
A heat-resistant brazing material such as No. 7 is used.

The thickness of the corrosion-resistant and wear-resistant alloy as a thin plate is 0.1 to 2w1.
A value of about 1 is preferable; a value of 2 or more makes rapid solidification difficult, and a value of less than 0 or 1 makes stable production difficult.

If the thickness of the heat-resistant brazing filler metal is less than α02, the bonding strength will be insufficient.
If α1m or more, the bonding strength decreases (LO2~0.
1 dew is preferred.

In addition, as short fibers added to CO-based alloys, sto
, 813N4, At, 01 etc. whiskers, se
a, carbon fiber, cut At203 long fiber, etc.
Commonly used ceramic fibers are used.

The shape is not particularly limited, but the diameter is 0.1 to 1 μm and the length is 1 μm.
The amount may be about 1 m to 1 m, and the addition method may be conveyance using a belt, injection using gas pressure, or the like. If the volume ratio of the ceramic short fibers to the CO-based alloy is less than 5%, no strength improvement will be observed due to the composite, and if the volume ratio exceeds 2(]'%, the ceramic short fibers may be unevenly dispersed. ~2
0% is preferred.

1 to 3 are perspective views showing one embodiment of the method for manufacturing a corrosion-resistant and wear-resistant material according to the present invention. FIG. 1 is a diagram illustrating the manufacturing process of a composite thin plate of a ceramic short fiber-dispersed CO-based alloy and a heat-resistant brazing filler metal using a rapid solidification device,
The brazing filler metal 2 melted in the crucible 1 is continuously dripped or sprayed onto one of the two rolls 3 . Furthermore, the CO-based corrosion-resistant and wear-resistant alloy 12 melted in the other crucible 11 is dripped or sprayed into the gap between the pair of rolls 5. At the same time, ceramic short fibers are supplied by gas pressure into the OO alloy molten metal pool in the gap between the pair of rolls 3 by the ceramic short fiber supply tube 4. Immediately thereafter, it is rapidly cooled by rolls 5 to obtain a thin plate 5. Second
The figure shows the corrosion-resistant and wear-resistant coating material 15 of this example obtained in this way, in which 6 is a CO-based corrosion-resistant alloy in which short ceramic fibers are dispersed, and 7 is a brazing material layer.

The corrosion-resistant and wear-resistant thin plates manufactured in this manner are pasted and fixed to the required locations of the high-temperature member via a brazing material layer, and then brazed and bonded in a vacuum or in a reducing atmosphere. FIG. 3 shows an application example in which a corrosion-resistant and wear-resistant thin plate 8 made by the method of the present invention is bonded to a high-temperature member 9.

(Example) Using the method of the present invention, Stellai) No. 6 alloy (5Ni-2)
8C! r-4W-5Fe-10) (Mitsubishi Metals, D6-
K) 104℃ by rapid solidification method using SiO whiskers and N1-B brazing filler metal J-5B-Ni1 as raw materials.
A thin plate with a thickness of 1 m was manufactured at a cooling rate of about 1 m/sec.

The amount of whiskers added was 15% by volume relative to the OO-based alloy.

When this thin plate was attached to turbine rotor blades and compared with conventional materials, favorable results were obtained, including superior strength and corrosion resistance, strong resistance to thermal fatigue and peeling, and extended life. .

(Effects of the Invention) The method for producing the corrosion-resistant and wear-resistant coating material of the present invention produces a base alloy thin plate by a rapid solidification method, so even difficult-to-process materials such as Co-based alloys can be easily processed [approximately 1,1 to 2W1]. It can be processed into thin plates, and because the crystal grains are fine and there is almost no segregation, it has superior strength and corrosion resistance compared to welded materials and ordinary processed materials. Furthermore, since the short ceramic fibers are rapidly cooled immediately after being added to the CO-based alloy, deterioration of the ceramic fibers can be suppressed. Furthermore, by combining it with a thin plate of brazing material, it becomes easier to braze along the shape of the joint surface, and the joint strength improves.

As described above, the method of the present invention applies to gas turbines.

This is an excellent method that can be applied to high-temperature components such as rotor blades of steam turbines, providing excellent corrosion and wear resistance, and significantly improving durability compared to conventional methods.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing a manufacturing method according to an embodiment of the present invention, and is a perspective view showing a process for manufacturing a thin alloy plate by rapid solidification. FIG. 2 is a perspective view of a coating material according to the invention. FIG. 3 is a perspective view showing an example of application of the coating material according to the present invention. Sub-agents 1) Meifuku agent Ryo Hagiwara -

Claims (1)

[Claims] (1) Production of a corrosion-resistant and wear-resistant coating material characterized by producing a composite thin plate with a heat-resistant brazing filler metal by a rapid solidification method while adding short ceramic fibers to a Co-based corrosion-resistant and wear-resistant alloy bath water stream. Method.