JPS6013418B2 - High strength copper alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high strength spring material having age hardenability.

Beryllium steel alloy is a typical example of a material that has been conventionally used as a high-strength spring material, but the high cost of raw materials naturally limits its uses.

This invention meets the demand for high-strength spring materials using cost-effective raw materials.

In general, it has been reported that spinodal decomposition is observed in steel-nickel-tin alloys and the material hardens when subjected to aging treatment at a certain component ratio or processing rate. However, with this copper-nickel-tin component alone, the crystal grain size tends to grow very large during the solution treatment of the material for age hardening, and it is said that when used as a practical alloy, it will cause roughness during bending and drawing of parts. Defects are recognized. There is also a method in which manganese is present as a diluent at a certain black ratio when obtaining the above-mentioned steel-nickel-tin alloy, but such a method not only complicates the manufacturing process but also requires strict conditions for temperature control. There's a problem.

In order to compensate for this drawback, the present invention adds a certain amount of manganese to suppress the coarsening of crystal grains without complicating the process.

Among the additive elements in this invention, nickel and tin have a lower limit of 8% and 3%, respectively, with the minimum component amount that provides age hardening.
%.

Also, the upper limits are 30% and 8%, respectively, based on workability.
And so. Regarding manganese, the lower limit was set at 0.2%, which is the amount at which the effect of suppressing coarsening of crystal grains is recognized, and the upper limit was set at 0.8% from the viewpoint of workability, similar to nickel and tin.

Manganese also has other effects as a deoxidizing agent. An embodiment of the present invention will be described below.

Samples were prepared with a pre-processing rate of 60% and a thickness of 0.3 ribs, and each composition material was subjected to solution treatment, and the grain size was measured and the properties after further processing were confirmed. The table shows the composition and typical characteristics of one example tested.

The tensile strength in the table is 1 at 850qo for each sample.
The strength was the highest when the crotch was subjected to 40% processing after solution treatment and when it was soaked for 100 minutes at 250 to 5000°.

Specifically, sample No. 1 is 425qo for 100 minutes, N
o. 2~No. 4 is the value obtained when heat treatment was performed at 450° C. for 100 minutes. The figure shows the relationship between melting treatment and crystal grain size for each sample.

The results shown in the table and figures show that this alloy has very good age hardenability, but the grain size is greatly influenced by manganese.

That is, it can be seen that when the amount of manganese is less than 0.2%, the crystal grains become coarser and the larger the content, the more suppressive effect there is.
As described above, this invention alloy can obtain high strength with a relatively low-cost raw material composition, and in practical use, it is possible to obtain surface roughness, which is a problem when the contact area is a bent or drawn part. This makes it possible to produce a material that is difficult to produce, that is, has a fine crystal grain size.

[Brief explanation of the drawing]

The figure shows samples No. 750~ for composition alloy 4
It is a figure which shows the relationship between the crystal grain size and heat treatment temperature when heat treatment was performed for 10 minutes each at 880 points.

Claims (1)

[Claims] 1. A high-strength copper alloy comprising, by weight, 8 to 30% of nickel, 3 to 8% of tin, and 0.2 to 0.8% of manganese, accompanied by inevitable impurities, and the balance being copper.