JPH01289593A - Heat resistant brazing filler metal of ni system - Google Patents

Abstract

PURPOSE:To effectively prevent the oxidation of Al so as to improve wettability and to facilitate brazing of heat resisting stainless steel parts by forming the heat resistant brazing filler metal of an Ni system of a specific compsn. and forming the same to a leaf or ribbon shape of an amorphous structure. CONSTITUTION:The brazing filler metal having the compsn. consisting, by weight, 1-15% Al, 13-23% Cr, and the balance substantially Ni is formed to the leaf or ribbon shape of the amorphous structure. The oxidation of the Al during the production of the brazing filler metal is prevented as far as possible by a rapid solidification method and the brazing filler metal can be easily formed to the leaf or ribbon shape. Since the brazing filler metal is produced without subjecting the same to grinding in such a manner, the oxidation of the Al is prevented and since the surface area is small, the oxidation of the Al during the heating up to the brazing temp. is lessened. Segregation of the components is low in the amorphous structure and the grain boundaries do not exist therein and, therefore, the structure itself is hardly oxidized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a Ni-based heat-resistant brazing material used for brazing heat-resistant metal parts, especially heat-resistant stainless steel containing AM such as a combustion tube of a combustion appliance. It relates to the brazing material used to braze parts.

[Prior Art] In general, brazing of stainless steel is considered to be more difficult than that of carbon steel due to the deterioration of wettability caused by the Cr contained therein. This is because Cr oxide is generated on the surface of stainless steel, which impairs wettability and makes brazing difficult.

For the purpose of facilitating brazing of such stainless steel, a filler material as shown in Japanese Unexamined Patent Publication No. 55-103297 has been proposed. This brazing material is characterized by having at least 50% amorphous structure, and is a Ni-based brazing material with a selective composition of Fe, Cr, B, and P.

[Problems to be Solved by the Invention] However, in the conventional brazing metal as shown in JP-A No. 55-103297, when it is used for brazing aluminum-containing heat-resistant stainless steel, which is the object of the present invention, Since the brazing filler metal does not contain An, a region with insufficient Al gold content is generated in the brazing part, which causes a problem of deteriorating the high temperature oxidation resistance of the brazing part.

Al-containing brazing materials have not been proposed in the past. This is because when making normal powder brazing filler metal, the number is oxidized during the pulverization process, and because the brazing material is powdered while being heated up to the temperature, the surface area is large and the surface area starts from A2. This is because these AM oxides deteriorate wettability and make brazing difficult. Therefore, at present, there is no optimum brazing material for use in brazing heat-resistant stainless steel.

The present invention was made in view of the current situation, and it effectively prevents the oxidation of A2 to improve wettability, facilitates brazing of heat-resistant stainless steel parts containing Al, and provides brazing with excellent properties. An object of the present invention is to provide an Al-gold-containing Ni-based heat-resistant brazing filler metal that can obtain the following properties.

In addition, the base material for brazing that is the object of the present invention is 8 Q: 2.00 to 4.00 J as a stand-in heat-resistant stainless steel.
Cr: 17.00-21. For example, J
Stainless steel such as ISS Old +2 can be cited as a representative example.

[2! l! Means/effect for solving W The Ni-based heat-resistant brazing material of the present invention to achieve this object is constructed as follows. That is, (1) Ni characterized in that it consists of A2: 1 to 15t, Cr: 13 to 23!6, and the remainder substantially Ni in weight percent, and is formed into a thin flake or ribbon shape with an amorphous structure. Heat-resistant brazing filler metal.

(2) A cross in weight%; 1 to 15%, Cr: 13 to 23%, Si: 3 to +2%, +2'lli to P near, B:
1. A heat-resistant Ni-based brazing filler metal, characterized in that it contains one or more of the following: the remainder being substantially Ni, and formed into a flake or ribbon shape with an amorphous structure.

It is.

Since the brazing material according to the present invention contains a predetermined amount of A4 and is formed into a thin flake or ribbon shape with an amorphous structure, the brazing material prevents the formation of an Al poor region in the brazing part. In brazing, the high-temperature oxidation resistance of the parts is improved, and oxidation of A2 is prevented, so wettability is greatly improved and good brazing properties are obtained.

[Details of the invention] The present invention will be explained in detail below.

First, the reason for limiting each component constituting the brazing filler metal according to the present invention will be described.

Al2 The base material targeted by the present invention contains Al in order to improve its oxidation resistance, and when a brazing filler metal is used for this, naturally brazing also involves improving the oxidation resistance of the base material. is required. For this reason, Al is considered to be an essential component in the brazing material of the present invention, but if Al is less than 1%, brazing will be difficult because of the Al content.
The content is low and the oxidation resistance of the base material cannot be maintained. Moreover, if A2 exceeds 15%, the wettability will worsen,
Brazing has poor properties. Therefore, 8n is 1 to 15%
The range of

Cr: This is added to improve the high-temperature oxidation resistance of the brazing part, but if it is less than 13%, this high-temperature oxidation resistance cannot be fully expected, and if it is added in excess of 23t, the ductility of the brazing part will decrease. and leads to deterioration of toughness. Therefore, Cr was set in the range of 13 to 23t.

Next, Si, P, and B, which are added as selective components, are all added for the purpose of lowering the melting point of the brazing material, and the reason for limiting the content of each is as follows.

Si: If it is less than 3%, it will not contribute much to lowering the melting point as a brazing material. In addition, if it is higher than 12*, brazing will cause deterioration of the part and brazing will reduce the properties, so Si is 3 to 12
'4.

P Near! If it is less than , it will not contribute much to lowering the melting point as a brazing material. Moreover, if it is higher than 12%, brazing will cause deterioration of the part, so P was set to 7 to I2%.

B: If it is less than $2, it does not contribute much to lowering the melting point as a brazing material. In addition, if the addition amount is higher than 5%, erosion of the base material will become severe and brazing properties will decrease.
B is 2 to 5%.

One or more of these Si, P, and B are appropriately selected within the above-mentioned content range.

Further, the brazing material of the present invention needs to be formed into a thin piece or ribbon shape with an amorphous structure. This aim is A
The purpose is to prevent the oxidation of No. 2 and to not reduce the wettability.

The step of forming a thin piece or ribbon-shaped brazing material with an amorphous structure can be achieved by employing a known rapid solidification method, that is, a method in which a brazing material of a desired composition is brought into a molten state and then rapidly cooled with a rotational quench width. good.

By this rapid solidification method, oxidation of A4 can be prevented as much as possible during the manufacturing process of the brazing material, and since it can be easily formed into flakes or ribbons, the surface area is much smaller than that in powder form.

As mentioned above, since it is produced without going through the pulverization process,
Brazing can reduce oxidation of AM during heating to temperature, since oxidation of L is prevented and the surface area is small. Furthermore, in an amorphous structure, the components are less biased and there are no grain boundaries, so the structure itself is difficult to oxidize. It is believed that oxidation of A-cross can be effectively prevented by forming the brazing filler metal into an amorphous structure and by forming it into a thin piece or ribbon shape with as small a surface area as possible. Note that it is also possible to use the thinned brazing filler metal in the form of even smaller pieces.

[Effects of the Invention] As explained above, the Ni-based brazing material according to the present invention contains an effective amount of An, which was conventionally considered difficult to contain, and improves wettability and exhibits good brazing properties. Therefore, A4
It can be said to be optimal for brazing heat-resistant stainless steel parts or Ni-based heat-resistant materials containing Al.

[Example] Using a brazing filler metal having the components shown in Table 1, brazing was performed using JIS SUH21 ferritic stainless steel as a base material. No. 2 to 4.6 to 12 in Table 1 are the present invention, No. 1
．． 5 and 13 are comparative examples. Nos. 1 to 12 are thin pieces or ribbons of brazing filler metal with amorphous structure.
, 13 is a powdered brazing material made by pulverization.

Table 1 No. 1 has a low Affi content in the brazing part,
Brazing has insufficient high-temperature oxidation resistance, so it is no.

In case 5, there was a situation where the brazing was defective. Also, no.

Sample No. 13 had poor wettability and poor brazing. On the other hand, Nos. 2 to 4 and 6 to 12 could be brazed, and the brazing content was sufficient to match that of the base material, and the oxidation resistance was also good. .

Claims (2)

[Claims] (1) Ni-based heat-resistant material consisting of Al: 1 to 15%, Cr: 13 to 23%, and the remainder substantially Ni in weight percent, and formed into a flake or ribbon shape with an amorphous structure. Brazing material. (2) Al: 1-15%, Cr: 13-23%, Si: 3-12%, P: 7-12%, B: 2-5% in weight% 1
1. A heat-resistant Ni-based brazing filler metal, characterized in that it contains one or more species, the remainder substantially consists of Ni, and is formed into a flake or ribbon shape with an amorphous structure.