JPH0571611A - Manufacture of blade part for torque converter - Google Patents

Abstract

PURPOSE:To prevent strength of a material from lowering in blazing after cold forming by using a hot or cold rolled steel plate material with components of C, Si, Mn, P, S, Cu, etc., and increasing its tensile strength by over a specified value more than that before cold forming. CONSTITUTION:A blade part 1 for a torque converter is made of a hot or cold rolled steel plate material with chemical components of C of 0.20% or below, Si of 0.50% or below, Mn of 0.05 to 1.00%, P of 0.03% or below, S of 0.03%, Cu of 0.2 to 2.00%, etc., and having a tensile strength of 20 to 60kgf/ mm<2> after hot or cold rolling. When brazing is made, a temperature for ordinary brazing of 900 to 1200 deg.C is held for 5 to 60min. Then the temperature is lowered from the blazing temperature directly to or increased after it is lowered to the room temperature once to 400 to 700 deg.C, and held for 5 to 180min. Thus the tensile strength of the material can be increased below 10 to 30kgf/mm<2> more than that before the brazing is made.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a blade part for a torque converter used for manufacturing a blade part which constitutes a torque converter.

[0002]

2. Description of the Related Art As a blade component forming a torque converter, for example, there is one shown in FIG.

That is, a vane component 1 for a torque converter such as a torque converter impeller and a turbine of an automatic transmission for an automobile shown in FIG.
Press-formed impeller shell 2, blade 3, core 4
Each component such as is fixed by a large number of caulking portions 5.

In order to increase the load accompanying the improvement in engine output in recent years and to reduce noise, etc., after fixing with the caulking portion 5, the contact portion of each component is further brazed using a copper brazing material. By doing so and firmly fixing, it is possible to prevent deterioration of strength and rigidity and generation of noise due to mutual displacement between parts.

[0005]

However, in such a conventional method for manufacturing a blade component for a torque converter, 1100 after being assembled into the blade component 1.
Since brazing is performed at a high temperature of around ° C, the strength characteristics obtained by controlled rolling, heat treatment, etc. at the time of production may be impaired by the structure transformation in the conventional solid solution strengthened type and composite structure type high strength steels. However, there is a problem that the strength of each part, which had been improved by work hardening during press molding, may be reduced due to softening due to recrystallization of the work hardened structure, and it is possible to solve these problems. It was a challenge.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is 1100 ° in order to meet the demands such as increase of load and improvement of quietness after being assembled into a blade part for a torque converter. It is an object of the present invention to provide a method for manufacturing a blade component for a torque converter, which can prevent the strength from decreasing even when brazing is performed at a high temperature around C.

[0007]

A method of manufacturing a blade component for a torque converter according to the present invention is, in weight%, C:
0.20% or less, Si: 0.50% or less, Mn: 0.0
5 to 1.00%, P: 0.03% or less, S: 0.03%
Hereinafter, when brazing is performed after cold forming using a hot or cold rolled steel sheet having a tensile strength of 20 to 60 Kgf / mm ² consisting of Cu: 0.20 to 2.00%, the balance Fe and impurities as a raw material. Directly from the application temperature or once cooled to room temperature and held at 400 to 700 ° C for 5 minutes or more to obtain tensile strength of 10 Kgf /
It is characterized in that it is configured to improve by ² mm ² or more, and the structure of the invention relating to the method of manufacturing such a blade component for a torque converter is a means for solving the above-mentioned conventional problems.

The construction of the method for manufacturing a blade member for a torque converter according to the present invention will be described in more detail below.

First, the range of component limitation of the raw material in the present invention will be described.

C is an element necessary for improving the strength, and the content should be selected according to the strength required for the product, but if it is contained in excess of 0.20%, it has press formability and weldability. Therefore, the content of C is set to 0.20% or less.

Si is an element necessary as a deoxidizer,
If the content of Si exceeds 0.50%, surface defects such as surface roughening occur during hot rolling. Therefore, the content of Si is set to 0.50% or less.

Mn is an element useful for improving the hardenability and as a deoxidizing agent, but if it is less than 0.05%, the required strength cannot be obtained, and if it exceeds 1.00%, the toughness decreases. Therefore, the Mn content is set to 0.05 to 1.
It was set to 00%.

Since P is an element that impairs cold workability,
The P content was 0.03% or less.

Since S is an element which impairs cold workability,
The content of S was set to 0.03% or less.

Cu is the most important element for the age hardenability of the steel sheet in the present invention. If the added amount is less than 0.20%, the age hardened amount is insufficient, and if it exceeds 2.00%, hot workability is caused. Is significantly reduced and economical efficiency is reduced, the Cu content is set to 0.20 to 2.00%.
And

In addition, 2.50% or less of Ni may be added to compensate for the deterioration of hot workability due to the addition of Cu.

In the present invention, the tensile strength after the hot or cold rolling is 20 to 6 having the above-mentioned chemical composition.
A hot or cold rolled steel sheet of 0 Kgf / mm ² is used as a raw material, and more preferably, after cold forming processing in which a processing strain of 10% or more is applied, brazing such as in-furnace brazing with copper brazing, etc. When carrying out, after maintaining at a normal brazing temperature of, for example, 900 to 1200 ° C for 5 to 60 minutes, the brazing temperature is cooled directly from this brazing temperature or once to normal temperature and then at a temperature in the range of 400 to 700 ° C.
By holding for about 1 minute or more and about 180 minutes or less, the tensile strength is finally improved in the range of 10 Kgf / mm ² or more and 30 Kgf / mm ² or less compared to before brazing.

In the present invention, the reason why it is desirable to set the brazing temperature to 900 to 1200 ° C. as described above is because the strength of the brazing portion is used as the brazing material for the ordinary torque converter vane component. This is because copper-based brazing filler metals are often used from the standpoint of economic efficiency.In this temperature range, the copper atoms in the components will form a solid solution in the steel, and the copper atoms will be supersaturated by cooling from that state. It becomes a solid solution state. Then, as shown in FIG. 2, when the aging temperature (heating temperature) is lower than 400 ° C. or higher than 700 ° C., the tensile strength of 10 Kgf / mm ² or more cannot be improved, and the same figure is obtained. As shown in No. ^2, it was revealed that the improvement of the tensile strength of 10 Kgf / mm ² or more cannot be obtained when the aging time is less than 5 minutes.

In consideration of economy, the heating time is 18
It is better to set it to 0 minutes or less.

[0020]

In the method of manufacturing a blade part for a torque converter according to the present invention, the C content is determined in consideration of strength, press formability, weldability, etc., and Si is taken into consideration in consideration of surface roughness during hot rolling. The content is determined, the Mn content is determined in consideration of hardenability, toughness, etc., the P and S contents are regulated in consideration of cold workability, and age-hardenability and hot workability are considered. Cu
2.50% considering the content and other hot workability
The following Ni is contained, and 0.01% to 0.
Including 10% Al, 0.000 considering machinability
From the brazing temperature when brazing after cold forming using a hot or cold rolled steel sheet having a tensile strength of 20 to 60 Kgf / mm ² as a material capable of containing 5 to 0.0050% Ca Directly or after cooling to room temperature, hold at 400-700 ° C for 5 minutes or more to obtain tensile strength of 10 Kgf / mm more than before cold forming.
^Since it is configured to be improved by ² or more, even when brazing is performed at a high temperature of about 1100 ° C after being assembled to the blade parts for the torque converter, the strength is prevented from being reduced, and the engine output is improved. It becomes possible to deal with the demand for increased load and improved quietness.

[0021]

EXAMPLE This example was applied to the vane component 1 for a torque converter shown in FIG.

This torque converter vane component 1 is
As described above, the present invention is applied to a torque converter of an automatic transmission for automobiles, in which the shell 2, the blade 3, the core 4 and the like are mechanically coupled by a large number of caulking portions 5, and at the same time brazing is performed. By adding joints, the structure is such that the mounting rigidity between the respective parts becomes higher.

Therefore, as shown in Table 1, the steel sheets of Examples 1 to 5 of the present invention having the components according to the present invention and the steel sheets of Comparative Examples 6 to 8 deviating from the components of the present invention (Comparative Example 6 does not contain Cu, Comparative Example 7 is Cu-excessive, Comparative Example 8 is SAPH45) applied as a material for the shell 2, the blade 3, and the core 4, and brazing is performed by maintaining the brazing temperature at 1150 ° C. for 20 minutes after cold forming, After that, once cooled to room temperature, immersed in a salt bath kept at 570 ° C for 30 minutes, and subsequently water-cooled, the tensile strength before cold forming, the cold formability, the tensile strength after heat treatment, The high speed rotation durability was investigated.

The results are shown in Table 1.

[0025]

[Table 1]

As shown in Table 1, the tensile strength before cold forming was 20 to 60 Kgf / in each of Examples 1 to 5.
It was in the range of mm ² , and the cold moldability was good in each of Examples 1 to 5, and it was possible to mold without problems.

Further, the tensile strength after heat treatment is from Example 1 to
In the case of 5, the tensile strength before cold forming was 10
It was improved by Kgf / mm ² or more.

On the other hand, in the case of Comparative Example 7, since the Cu content was too large, cracks or dimensional defects occurred during molding, resulting in poor cold formability.

When evaluating the high-speed rotation durability shown in Table 1, a torque converter incorporating the above parts was subjected to a high-speed rotation durability test under the conditions shown in Table 2, and then the shape change due to cracking or plastic deformation was performed. When was observed, it was evaluated as ×, and when there was no problem, it was evaluated as ◯.

[0030]

[Table 2]

As a result, in each of Examples 1 to 5, the high-speed rotation durability was excellent, whereas in Comparative Examples 6 and 8, the high-speed rotation durability was poor. It was

In addition, when it is necessary to further increase the strength of the blade component for a torque converter by the manufacturing method described in the above embodiment, a soft nitriding treatment is used instead of the age hardening treatment after brazing. It was also found that it is possible to significantly improve the fatigue strength by applying.

[0033]

According to the method of manufacturing a blade part for a torque converter according to the present invention, C: 0.20% or less, Si: 0.50% or less, and Mn: 0.05 to 1.00 in weight%.
%, P: 0.03% or less, S: 0.03% or less, Cu:
A hot or cold rolled steel sheet having a tensile strength of 20 to 60 Kgf / mm ² consisting of 0.20 to 2.00% and the balance Fe and impurities is used as a raw material, and when brazing is performed after cold forming, a predetermined amount is set after brazing. Since the heat treatment is performed, the strength reduction of the member due to the structural transformation and recrystallization in the brazing process is prevented, and it is 10 kg less than before cold forming.
Since an improvement in tensile strength of f / mm ² or more can be obtained, it is possible to have characteristics that are significantly superior in strength and rigidity as compared to conventional torque converter blade parts, and to improve engine output. The great effect that it becomes possible to deal with the demand for the increase of the load and the improvement of the quietness is brought about.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing a structure of a turbine runner which is a part of a torque converter blade component to which a method for manufacturing a torque converter blade component according to the present invention is applied.

FIG. 2 is an explanatory diagram showing a relationship between a heat treatment time and a heating temperature and a tensile strength in an aging treatment of steel applied in a method for manufacturing a blade component for a torque converter according to the present invention.

[Explanation of symbols]

 1 Blade parts for torque converter 2 Shell 3 Blade 4 Core

Claims (1)

[Claims] 1. By weight%, C: 0.20% or less, Si:
0.50% or less, Mn: 0.05 to 1.00%, P:
0.03% or less, S: 0.03% or less, Cu: 0.20
~ 2.00%, the balance of Fe and impurities from a hot or cold rolled steel sheet having a tensile strength of 20 to 60 Kgf / mm ² and used as a raw material when performing brazing after cold forming directly from the brazing temperature or once at room temperature. A method of manufacturing a blade component for a torque converter, characterized in that the tensile strength is improved by 10 Kgf / mm ² or more as compared with that before cold forming by holding at 400 to 700 ° C for 5 minutes or more after cooling.