JPH05169282A - Liquid phase diffusion joining method of steel - Google Patents

Abstract

PURPOSE:To shorten the joining time and to make possible the mass-production at the liquid phase diffusion joining method of steels by using the alloy having a specific composition as the inserting material of powder or amorphous alloy. CONSTITUTION:An insert material 2 composed of the paste like powder of the brazing material or an amorphous foil is heated at the state interposing it between steels of the material to be joined, and the insert material 2 molten with heating is joined with diffusing at the temperature under the solid phase line. At the time, the composition of the powder or the amorphous foil is made to the alloy containing 2-5wt.% C, or 2-10wt.% (C+B). C reduces the melting point of Fe as same as B and Si, etc. Further, the diffusion in austenite is sooner than P or Si, therefore, C and B together are most suitable as an element adding as the insert material for the liquid diffused junction of steel. In such a way, the joining speed is made speedy, and the sound joining part can be obtained.

Description

Detailed Description of the Invention

[0001]

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid phase diffusion bonding method for steel materials.

[0003]

2. Description of the Related Art (1) Japanese Patent Application Laid-Open No. 2-121781 and (2) Japanese Patent Application Laid-open No. 2-29
There is a gazette of 9767.

Each of these is heated in a state in which an insert material made of a paste-like powder which is a brazing material or an amorphous foil is interposed between steel materials which are materials to be joined, and the insert material melted by heating is solidified into a base metal. This is a method of diffusion bonding at a temperature below the phase line.

[0005]

However, in the above diffusion bonding method, boron (B), silicon (Si) and phosphorus (P) are attached as melting point lowering elements as insert materials, and as a result, There is a problem that P forms a harmful compound with Fe, Si and P diffuse slowly in Fe, and B is expensive.

[0006] The present invention has a technical problem in a liquid phase diffusion bonding method between steel materials, which is capable of shortening the bonding time and enabling mass production.

[0007]

[Constitution of the invention]

[0008]

The technical means for solving the problems are as follows.

A paste-like powder which is a brazing material, or an insert material made of amorphous foil is heated in a state in which a material to be joined is interposed between steel materials, and the insert material melted by heating is heated to below the solidus line of the base material. In the method of diffusion bonding at temperature, the composition of the powder or amorphous foil as the insert material is 2 to 5 wt% in C, or 2 to 1 in (C + B).
This is a liquid phase diffusion bonding method for a steel material made of an alloy containing 0 wt%.

[0010]

In the liquid-phase diffusion bonding method, C is an element that lowers the melting point of Fe equally with P, B, Si and the like.

Further, diffusion in austenite is caused by P and Si.
Therefore, C is optimal as an element to be added together with B as an insert material for liquid phase diffusion bonding of steel materials.

[0012] C is much cheaper than B, and the steel material always contains a certain amount of C.
Does not deteriorate the properties of the base material even if it diffuses into the base material to some extent, and the joining speed is faster than this, and a sound joint can be obtained.

[0013]

EXAMPLES Examples will be described below.

Arc welding and resistance welding are usually used for joining steel materials.

However, in the above joining method, since the base material is melted, welding distortion caused by solidification shrinkage occurs, and thus joining of precision products often requires post-processing.

As a method for dealing with this problem, liquid phase diffusion bonding is performed, and only a thin insert material sandwiched between the materials to be bonded is melted and bonded at a temperature equal to or lower than the melting point of the base material. It will be.

However, this method requires the complete diffusion of additional elements for the temperature drop of the insert material,
For this reason, it takes a long time for joining, which is a problem as a joining method for mass production.

To solve this problem, the joining method of the present invention uses C or C + B, which has a large diffusion coefficient in the steel material, as an additive for the insert material for lowering the temperature and realizes extremely fast joining.

FIG. 1 shows the present embodiment, 1 is a material to be joined, 2 is an insert material, 3 is a shield gas, 4 is a heating device, and 5 is a pressurizing device.

In the case of joining using the above apparatus, the composition of the insert material is combined to join the materials to be joined, the form of the insert material is changed to paste (with powder), and the joining temperature and joining time are changed. Liquid phase diffusion bonding was performed.

The results are shown in Table 1.

[0022]

[Table 1]

From Table 1, when the insert materials containing C and B in Examples 1 to 6 are used, the joining is completed much faster than the conventional methods 1 to 3, and the joining strength is also extremely strong. is there.

[0024]

[Effect] The present invention has the following effects.

The insert material containing carbon is
(1) High diffusivity and fast bonding speed.

(2) Does not form harmful compounds with Fe.

(3) It is very inexpensive compared to other elements.

[Brief description of drawings]

FIG. 1 shows a liquid phase diffusion bonding apparatus of this embodiment.

[Explanation of symbols]

 1 Material to be bonded 2 Insert material 3 Shield gas 4 High frequency heat source 5 Pressurizing device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Ishii 2-1-1 Asahi-cho, Kariya city, Aichi Prefecture Aisin Seiki Co., Ltd.

Claims (1)

[Claims] 1. A base metal solid line of an insert material, which is a paste-like powder which is a brazing material, or an insert material made of amorphous foil, which is heated while being interposed between steel materials which are materials to be joined and which is melted by heating. In the method of diffusion bonding at the temperature below, the composition of the insert material powder or amorphous foil is 2 to 5 wt% C, or 2 to 1 (C + B).
A liquid phase diffusion bonding method for a steel material made of an alloy containing 0 wt%.