JPS58161772A - Carburizing and brazing method of steel member - Google Patents

Abstract

PURPOSE:To perform brazing and carburizing of steel members simultaneously, by forming a composite material to make the proportion of Cu, Sn within specified range in weight by using the first blank material consisting essentially of Cu and the second blank material consisting essentially of Sn and applying this material to the brazed part of steel members. CONSTITUTION:The first thin wiry material A consisting essentially of Cu and the second thin wiry material consisting essentially of Sn are brought close to each other and bound by a holding device to prevent separation, and a composite material C in which proportion of Cu and Sn is within the range of (85:15)- (65:35) in weight. This composite material C is placed near the upper part of brazed part 4 of steel members 2, 3, and the steel members 2, 3 are put in a carburizing and quenching furnace. After carburizing, the members are taken out from the carburizing and quenching furnace, and quenched. Thus, brazing and carburizing are carried out simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to carburizing and brazing properties of steel parts in which carburizing and brazing are simultaneously performed on steel members.

For example, in the case of gears used in automobile transmissions, multiple gear members with different diameters are individually machined for manufacturing reasons, and then these gear members are joined to form an integrated gear. It may be necessary to do so.

Brazing is one of the joining methods for such steel members, but it is also possible to braze the steel members at the same time as carburizing by using the heat from the charcoal firing process. This method has already been attempted (as a prior art, see, for example, Jikko Sho Glow, Publication No. 20/θ). This method is excellent in that it contributes to energy saving and is a simple process, but there is an optimal temperature range for carburizing, and there are several conventional brazing materials that can be used within that temperature range. There is a problem in that if the brazing material is limited to certain types and is used as it is, it cannot be applied to reduce the cost of brazing and stabilize the quality. That is, usually
The carburizing treatment of steel parts is maintained at a temperature of around 200°C for a certain period of time, and brazing materials that can be used at the above temperature include brass brazing, copper, manganese brazing, silver brazing, and copper-resistant brazing. . However, the high vapor pressure of zinc as a component in brass solder easily vaporizes and is harmful to the carburizing atmosphere, while in copper-manganese solder, manganese is extremely easily oxidized, which may affect the quality of the soldered product. It becomes stable. In addition, silver solder is expensive and is not suitable for producing elbows.

Furthermore, because the tin content of existing bronze solders is less than 76% by weight, the melting point is as high as 900°C or higher (carburizing and brazing cannot be performed at the same time.In order to lower the melting point, the tin content is 76% by weight). Although it is possible to increase the tin content to more than 2%, there is a problem that simply increasing the tin content as an alloy component causes intermetallic compounds to precipitate in the alloy, making the material brittle and impairing workability, making it impossible to form it into a wire rod. .

The present invention has been made in view of the above problems, and includes:
Separate copper-based powders, fine wires, and other materials (
(hereinafter referred to as the first material) and a material such as powder or thin wire that also has tin as its main component (hereinafter referred to as the second material), and at that time, the overall component ratio of copper and tin is in!
? 6: /6 to l,,! Adjusting the distribution of the seventh material and the second material so that ;:13; forms a composite material,
Next, the composite material is placed on the bran bone part of the steel member, and the composite material is alloyed during the carburizing process so that brazing and carburizing can be performed simultaneously, thereby solving the problems of the conventional method. That is.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below with reference to the drawings.

The first material A used in the present invention is pure copper processed into powder or fine wire, or a copper-tin binary alloy whose main component is copper, and when a copper-tin alloy is in the form of powder, the content ratio of both is particularly important. However, in the case of a thin wire, the tin content is preferably 76% by weight or less in order to process it into the thin wire. Second
Material B is pure tin processed into powder or fine wire, or a tin-copper binary alloy whose main component is tin, and the copper content is usually jθ Jusha%.
It is as follows.

A composite material C is formed by combining the first material A and the second material B. When forming the composite material C, considering alloying and ease of handling after forming the composite material, if the first material A and the second material B are thin wires, they are twisted together, and if they are powders, they are pasted together. The wire rods are formed into wire rods that are restrained by a holding means such as the like so that they are brought close to each other and do not separate. Moreover, in that combination, is the overall component ratio or weight ratio of copper and tin as composite material C 7? The distribution of the first material and the second material is adjusted in advance so that it falls within the range of , f: /, 3 to t, 5:3.5. In addition, if the image materials A and B are thin lines, copper plating or tin plating is applied to the first material A and the second material B in order to set the desired ratio within the range of component ratios listed above. By doing so, the ratio can be adjusted as appropriate. The reason for limiting the component ratio of copper and tin to the range E is because if tin is less than 76% by weight relative to copper, the melting point of the copper-tin alloy will be unsuitable when alloyed with composite material C by carburizing treatment. This is because if the tin content is 35% by weight or more, the strength of the brazed bone portion of the steel member after brazing will be low, and if the tin content is large, the cost required for brazing will be high.

After forming the composite material C in this way, the composite side is cut to a required length, and then the wax bone portions 4 of the steel members 2 and 3 are
The steel members 2 and 3 are placed in a gas carburizing and quenching furnace (not shown) and carburized. In this carburizing process, the steel members 2 and 6 are held at a temperature of 200°C after AiT for a predetermined time, so first, the composite side C
The second material B melts and covers the surface of the first material A, and tin diffuses into the first material A to promote alloying, and the melting point of the first material A decreases. The material A is also melted, and the first material A and the second material B are mixed, and due to their wetting properties, they are spread throughout the wax bone portions 4 of the steel members 2 and 3. Subsequently, the steel members 2 and 3 are taken out of the gas carburizing and quenching furnace and quenched, thereby obtaining a product 1 in which brazing and carburizing have been completed simultaneously.

Furthermore, an experimental example based on the above embodiment will be shown below.

<Composite material C> See Figure 1.

9fJ/Material A; 0/III+ diameter tin-plated pure copper wire.

Second material: Pure tin wire with a diameter of 0/trm.

Two pieces of the first material A and two pieces of the second material were twisted together and formed. What is the composition ratio of copper and tin after twisting? 0
: 20 (weight ratio).

Steel members 2, 3> Rolling wheel member 2; Steel type JIS standard SCR, 2, 2 Clutch gear member 3; Steel type JIS standard SCR, 4, the above-mentioned composite material C cut into a required length was arranged in a ring shape on the upper part of the wax bone portion, placed in a carburizing and quenching furnace, and carburizing and brazing treatment was performed.

Carburizing and brazing metal treatment conditions> Atmosphere in gas carburizing and quenching furnace; temperature 230°C, dew point -6°C,
In endothermic gas.

Holding time: 3 hours Both gears 2 and 3 were carburized and brazed under the above conditions, and the shear strength of the wax bone portion 4 of the integrally molded gear 1 was measured.

As a result, a shear strength of /♂6Ky/rd was obtained.

This sufficiently satisfies the required shear strength.

As described above, according to the present invention, the first rope material containing copper as a main component and the second material containing tin as a main component have a composition ratio of copper to tin in a weight ratio of 3 to 3. , 5:/j to A, 5:36 to form a composite material by restraining it with a holding means, and applying the composite material to the wax bone portion of the steel member to apply the composite material during the carburizing process of the steel member. Since the alloy is alloyed and brazing and carburizing can be performed simultaneously, the cost required for brazing is reduced to 1] compared to carburizing using conventional brazing materials. Reliably melts at the carburizing temperature, and
The joint strength of the wax bone part after brazing is also ensured, which stabilizes the quality of the manufactured parts, making it possible to reduce the cost of brazing and stabilize quality at the same time, which was not possible with conventional methods. This has an excellent effect.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, FIG. 7 is a perspective view of a composite material formed by twisting, FIG. 2 is a vertical cross-sectional view showing a state in which the composite material is applied to a steel member, and FIG. 3 is a carburized solder. FIG. 3 is a vertical cross-sectional view of the integrated product after the application process.

Claims (1)

[Claims] (1) A primary material such as a powder or thin wire containing copper as a main component and a second material such as a powder or thin wire containing tin as a main component are held close to each other and restrained by a holding means that holds them in a non-discrete state. and the overall copper and tin component ratio is j'6 in terms of weight ratio.
: /6 to Otsuj: 3. The method is characterized by forming a composite material within the range of s, placing the composite material on the brazing part of the steel member, putting it in a carburizing furnace and heating it, and brazing and carburizing the steel member at the same time. carburizing brazing properties of steel parts.