JPS60224726A - Copper alloy with superior corrosion resistance - Google Patents

Abstract

PURPOSE:To obtain a Cu alloy with superior corrosion resistance by adding specified percentages of Ni, Mg and Al to Cu. CONSTITUTION:A Cu alloy consisting of, by weight, 0.005-0.5% Ni, 0.01-0.5% Mg and/or 0.01-0.5% Al and the balance Cu with inevitable impurities is manufactured. The Cu alloy has superior corrosion resistance, and when the alloy is used, the life of the fins of a heat exchanger is prolonged and the thickness can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copper alloy with excellent corrosion resistance, and is intended to extend the lifespan and reduce the thickness of the fins of heat exchangers, particularly automobile radiators.

Properties required for automotive radiator fin materials 1) Excellent thermal conductivity.

2) Excellent heat resistance.

3) Excellent workability and uniform workability over the entire length of the material strip. 4) Excellent soldering properties.

However, there is no material other than copper or copper alloy that can satisfy all of 9 or more, and currently tin-containing steel is often used.

However, recently, due to worsening atmospheric environmental conditions and thinning of materials, conventional soot-filled copper has low corrosion resistance, so there is a desire to develop copper alloys with even better corrosion resistance. Ta.

In view of this point, the present invention provides a copper alloy having excellent corrosion resistance for use in radiator fins. That is, 1 the present invention includes Ni and any one of α005~α5wt (furthermore, Mgα01~α5Δwt, Alα01~G, Swt)
The present invention relates to a copper alloy with excellent corrosion resistance, which contains one or two types of copper and the remainder is steel and unavoidable impurities.

Next, the reasons for limiting the alloy components and contents constituting the nine invention alloys will be explained.

The reason why the N1 content is set to (1005~α5 wtl) is.

When the N1 content is less than (L 005 wt1), no improvement in corrosion resistance and heat resistance 1 strength is observed;
When it exceeds 5 wtl, the effect of improving corrosion resistance is saturated.

This is also because thermal conductivity decreases.

The reason for setting the Mg content to α01~0.5wt1 is that M
When the g content is less than 1 wt% αo, corrosion resistance and heat resistance are exhibited.

No improvement in strength was observed, and on the contrary, the Mg content was 0.5 wt.
This is because, if it exceeds l, the effect of improving corrosion resistance will be saturated and the thermal conductivity will decrease. The reason why the Al content is set to 0.01 to 0.05 wt4 is that when the Al content is less than 0.01 wt, no improvement in corrosion resistance, heat resistance, or strength is observed.

Conversely, if the A1 content exceeds αs wtl, the effect of improving corrosion resistance is saturated and the thermal conductivity decreases.

The material of the present invention will be explained below with reference to Examples.

EXAMPLES Alloys having various compositions shown in Table 1 were melted, hot rolled, appropriately annealed, and then cold rolled to form plates of α4-thickness. As a result of the research, it was found that temperature, humidity, and salinity are important factors in atmospheric corrosion of radiator fins, so the following test method was used as a reproduction test to evaluate the corrosion resistance of the sample material. That is, 70°C.

After 15 days had elapsed, it was exposed to an atmosphere with a relative humidity of 90°C, and during the course of the test, artificial seawater shown in Table 2 was appropriately sprayed.

Acid washing was performed to reduce weight loss (W9) before and after the test. This weight loss is converted to 1 c1m' per day and the corrosion rate (mld
).

Heat resistance strength was evaluated by holding a cold-rolled material with a final workability of 50 at each temperature for 30 minutes, and setting the temperature at which the hardness reached 804, which is the hardness of the cold-rolled material, as the softening temperature.

Thermal conductivity was evaluated by electrical conductivity, which is correlated with this.

These results are shown in Table 3.

According to Table 5, comparative alloy sample numbers 1 to 4, and 7 have inferior corrosion resistance to the invention alloy, and comparative alloy sample numbers 5, 6, and 7 have inferior corrosion resistance to the alloys of the present invention.
Nos. 8 to 10 are inferior in thermal conductivity to the alloys of the present invention. On the contrary, it can be seen that the alloy of the present invention has excellent corrosion resistance, strength, heat resistance, and thermal conductivity in a well-balanced manner.

Therefore, it can be seen that the alloy of the present invention is particularly suitable as a radiator fin material for automobiles.

Table 1 (unit: wt%) Ni MgAl -8y---PI Ou-Comparative alloy 1 α003 - - - - Remaining 20.46 -
- - - 3 α21 0.006 - - - 40.37 - α007 - - 50.240.74 - - - 6 α09 - 0.59 - - 7 α31 Q, OO! SQ, 004--8 0
．． 25 0.56 α74 − −9 0.54 0.
72 0.001 - -Table 2 Artificial seawater composition

Claims (1)

[Claims] N1α005 ~ [Including LSwt, further Mg0.0
A copper alloy with excellent corrosion resistance, containing one or two of the following: 1 to 0.5 wt, A1α01 to [LSwt, the balance being steel and unavoidable impurities.