JP3104351B2 - Liquid phase diffusion bonding method for steel - Google Patents

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 method for liquid phase diffusion bonding of steel.

[0003]

2. Description of the Related Art The prior art relating to the present invention includes (1) Japanese Patent Application Laid-Open No. 2-117881 and (2) Japanese Patent Application Laid-Open No. 2-29.
There is a publication of 9767.

[0004] In any of these, a paste-like powder, which is a brazing material, or an insert material made of an amorphous foil is heated in a state where it is interposed between steel materials to be joined, and the insert material which is melted by the heating is solidified into a base material. In this method, diffusion bonding is performed at a temperature equal to or lower than the phase line.

[0005]

However, the above-mentioned diffusion bonding method uses boron (B), silicon (Si) and phosphorus (P) as an insert material as a melting point lowering element. P forms a harmful compound with Fe, Si and P have a problem that diffusion in Fe is slow, and B is expensive.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid phase diffusion bonding method between steel materials.

[0007]

Configuration of the Invention

[0008]

The technical means for solving the problems are as follows.

[0009] An insert material made of a paste powder or an amorphous foil as a brazing material is heated in a state where a material to be joined is interposed between steel materials, and the insert material melted by heating is heated to a temperature below the solidus of the base material. In the method of diffusion bonding at a temperature, the composition of the powder or the amorphous foil as the insert material is such that C is 2 to 5 wt% or (C + B) is 2-1.
This is a liquid phase diffusion bonding method for a steel material made of an alloy containing 0 wt%.

[0010]

In the above liquid phase diffusion bonding method, C is an element such as P, B, Si, etc., which lowers the melting point of Fe equally.

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

C is much cheaper than B, and steel always contains a certain amount of C.
Does not degrade the properties of the base material even if it is slightly diffused into the base material, thereby increasing the bonding speed and obtaining a sound bonded portion.

[0013]

Embodiments will be described below.

For joining steel materials, an arc welding method or a resistance welding method is usually used.

However, in the above-mentioned joining method, welding distortion due to solidification shrinkage occurs because the base material is melted, and post-processing is often required for joining precision products.

Liquid phase diffusion bonding is performed as a method to cope with this problem. Only a thin insert material sandwiched between materials to be bonded is melted and bonded at a temperature lower than the melting point of the base material. It becomes.

However, this method requires complete diffusion of the additional element for the temperature drop of the insert material,
Therefore, it takes a long time for joining, and there is a problem as a joining method for mass production.

To solve this problem, the joining method of the present invention achieves extremely fast joining by using C or C + B having a large diffusion coefficient in a steel material as an additive for an insert material for lowering the temperature.

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

When joining using the above-mentioned 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 the joining time are changed. To perform liquid phase diffusion bonding.

Table 1 shows the results.

[0022]

[Table 1]

According to Table 1, when the insert materials containing C and B are used in Examples 1 to 6, the joining is completed very quickly and the joining strength is extremely strong as compared with the conventional ones. is there.

[0024]

The present invention has the following effects.

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

(2) No harmful compounds are formed with Fe.

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

[Brief description of the drawings]

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

[Description of Signs] 1 Material to be joined 2 Insert material 3 Shielding gas 4 High frequency heat source 5 Pressurizing device

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-77063 (JP, A) JP-A-2-1211781 (JP, A) JP-A-5-31588 (JP, A) JP-A-5-31588 131279 (JP, A) JP-A-2-185940 (JP, A) JP-A-55-57389 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 20/00-20 / 16

Claims (1)

(57) [Claims] 1. An insert material made of a paste powder or an amorphous foil as a brazing material is heated in a state where it is interposed between steel materials to be joined, and the insert material melted by heating is used as a base material solid-state wire. In the method of diffusion bonding at the following temperature, the composition of the powder or amorphous foil as the insert material is 2 to 5% by weight of C or 2 to 1% of (C + B).
A liquid phase diffusion bonding method for a steel material made of an alloy containing 0 wt%.