JPS6134155A - Copper alloy having superior corrosion resistance - Google Patents

Abstract

PURPOSE:To obtain a Cu alloy having superior heat resistance, heat conductivity and corrosion resistance by adding specified amounts of Pb, Co and other metal to Cu. CONSTITUTION:A Cu alloy consisting of 0.005-0.1wt% Pb, 0.01-1.0wt% Co, 0.01-1.0wt% one or more among Al, Sn, Mg, Ni, Te, In, Cd, As, Mn, Cr, Ti, Si, Zn, Be, Fe and P, and the balance Cu is manufactured. Since the alloy has superior heat resistance, heat conductivity and corrosion resistance, the alloy shows superior characteristics as a material for a heat exchanger, especially for the fins of a radiator for an automobile and is effective in reducing the thickness of the heat exchanger and prolonging the service life.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object] The present invention relates to a copper alloy with excellent corrosion resistance, and is intended to reduce the thickness and extend the life of heat exchangers, particularly radiator fins for automobiles.

[Conventional technology]

The fins of an automobile radiator are connected to the radiator tube and have the function of dissipating the heat of the cooling medium flowing inside the tube into the atmosphere.Therefore, the characteristics required of the fins are heat resistance and thermal conductivity. Conventionally, tin-containing copper has been used as a material that satisfies these required characteristics.

However, in recent years, the fins of automobile radiators have been severely corroded due to worsening environmental conditions due to an increase in SO and scum, exhaust gas, coastal atmosphere containing seawater, and even snow melting agents sprayed during snowfall, which has seriously affected the heat dissipation performance and lifespan of the radiator. Problems such as significant damage to the materials are now attracting attention. Furthermore, with the recent trend toward lighter automobiles, the fins are also becoming thinner, and even mild corrosion can lead to a deterioration in the performance of the radiator.

Under these circumstances, the current fin material, tinned copper thin plate, has low resistance to corrosion.

Furthermore, there was a desire to develop a copper alloy with excellent corrosion resistance.

〔composition〕

As a result of research conducted in view of the above points, the present invention relates to a copper alloy having excellent corrosion resistance for use in heat exchangers, particularly for use in automobile radiator fins.

The present invention is PI) 0.005-0.1wt, OoO, 0
1-1. Owt% and A1. Sn, Mg, Ni, Te,
In, Cd, As, Mn, Cr, Ti
.

If one of Si, Zn, Be, Fe, P, 〈 means two or more of them from 001 to 1. The present invention relates to a copper alloy with excellent corrosion resistance, which contains Owt4 and the remainder is O and inevitable impurities.

Next, the reasons for limiting the alloy components constituting the present invention will be explained.

The reason why the pb content is set at 0.005 to 0.1 wt.

When the Pb content is less than o, o o 5 wt%, no improvement in corrosion resistance is observed;
If the temperature exceeds t4, the effect of improving corrosion resistance is saturated and hot embrittlement occurs, causing problems in manufacturing. Co content 0
．． The reason why it is set as 01 to 1, Owtl is that the Co content is α
If the 01 wt' content is less than 1, no improvement in corrosion resistance will be observed, and if the 00 content is less than 1. This is because when the OWt exceeds 96, the effect of improving corrosion resistance and heat resistance is saturated and the thermal conductivity decreases. Al, Sn, Mg, Ni.

Te, In, od, As, Mn, Or, Ti, Si, Z
One or more of n, Be, Fe, P is 0
01-1. The reason for Owtl is Al, Sn,
Mg, Ni, Te, Eng, Oct, As, Mn, Or,
Ti.

If one or more of Si, Zn, Be, Fe, and P is less than 0.01 wt%, no improvement in corrosion resistance will be observed, and if it exceeds 20 wt%, the effect of improving corrosion resistance and heat resistance will be reduced. This is because the thermal conductivity decreases as the temperature becomes saturated.

As mentioned above, Pb, Oo and A1. Sn, Mg, Ni, T
e, In.

C4, As, Mn, Or, Ti, Si, Zn+Be+F
By adding two or more of e+P in combination, the corrosion resistance is much improved compared to when these elements are added alone.

In addition, as the combined amount of these elements increases, the thermal conductivity decreases, so in order to maintain good heat dissipation of the radiator fin, the total amount of two or more elements added should not exceed t s wtl. is desirable.

Next, examples of the alloy of the present invention will be described.

, [Example] Alloys having the various compositions shown in Table 1 were melted and hot-rolled and cold-rolled with appropriate annealing to form a plate with a thickness of 14 m. As a result of research, it was found that temperature, humidity, and salinity are important factors in atmospheric corrosion of radiator fins.
The corrosion resistance of the sample materials was evaluated using the following test method. That is, the specimens were exposed to an atmosphere of 70° C. relative humidity and 90° C., and were sprayed with artificial seawater shown in Table 2 as needed during the test, and after 15 days had passed, they were pickled to determine the weight loss before and after the test. This weight loss was converted into corrosion rate per 1d-1 day.

Heat resistance was evaluated by holding a cold-rolled material with a final workability of 50 parts at each temperature for 30 minutes, and setting the temperature at which the hardness becomes 80 parts of the hardness of the cold-rolled material as the softening temperature. Thermal conductivity was evaluated based on electrical conductivity, which is correlated with thermal conductivity.

These results are shown in Table 3. According to Table 3, Pb,
C! o and AI, Sn, Mg, Ni, T
o, Eng, Cd, As, Mn, Or.

Alloys to which one or more of Ti, Si, Zn, Be, Fe, and P are added in combination (Mu9 to 29) are compared with alloys to which Ti, Si, Zn, Be, Fe, and P are added in combination (Mu9 to 29), and to conventional alloys to which Ti, Si, Zn, Be, Fe, and P are added (Mu8). It can be seen that it has excellent corrosion resistance. As described above, the alloy of the present invention has excellent corrosion resistance, heat resistance, and thermal conductivity.

It is an excellent alloy with well-balanced properties suitable for use in heat exchangers, especially as an automobile radiator fin material.

Table 2 Table 3

Claims (1)

[Claims] Pb0.005~0.1wt%, Co0.01~1.0
wt% and Al, Sn, Mg, Ni, Te, In, Cd
, As, Mn, Cr, Ti, Si, Zn, Be, Fe,
0.01 to 1.0wt of one or more types of P
A copper alloy with excellent corrosion resistance, consisting of % Cu and unavoidable impurities.