JPS609062A - Manufacture of substrate for lead storage battery - Google Patents

Abstract

PURPOSE:To increase mechanical strength of a substrate by performing heat treatment of a lead alloy rolled plate containing a specific amount of Sb and As respectively at a specific temperature and for a specific time followed by quenching at a specific temperature in water. CONSTITUTION:Before and after a lead alloy rolled plate consisting of Sb manufactured by continuous casting rolling 2.1-4.5m/o, As 0.15-0.25m/o, the rest Pb is mechanically processed by stamping or expanding, the heat treatment is performed at 230-240 deg.C for 5-20min followed by quenching at 0-40 deg.C in water. In the case of an amount of addition under 2.1m/o, an effect of improving strength is little, while in case of exceeding 4.5m/o, self-discharge increases thus shortening a life of a battery. Further, when As is added, a crystal grain becomes fine while increasing strength. When the temperature of heat treatment is under 230 deg.C, the strength increases but endurance of 7.5kgfmm.<-2> can not be reached, while in case 240 deg.C is exceeded, it approaches to the melting point of a lead alloy thus making it unable to be heated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for manufacturing a lead-acid battery substrate.

Lead alloy rolled sheets obtained by the conventional continuous casting and rolling method have excellent workability and can be produced in large quantities due to continuous operation, but they have poor mechanical strength and cannot be used as substrates for storage batteries after repeated charging and discharging cycles. This causes elongation and easily causes short circuits, shortening the lifespan of the storage battery.

Therefore, there is a strong demand for increasing the mechanical strength of such substrates, but no improvement method has been developed.

Note that even if the lead alloy substrate formed by continuous casting and rolling was left as is, it could not be strengthened by age hardening.

In view of the current situation, the present invention is the result of extensive research and development of a method for manufacturing a storage battery substrate having excellent mechanical strength. That is, the method of the present invention uses continuous casting and rolling process to produce sp 2.1 to 4.5 m10, As
O, 15 to 0.25 m10, the balance being PB, before or after punching or machining such as extract/gun at 2300 to 240°C for 5 to 20 minutes.
After heat treatment for minutes, o.

It is characterized by being rapidly cooled in water at ~40°C.

In the method of the present invention, the strength of the 6 pb gold alloy is increased by adding 5 bt to the alloy composition, but if the addition amount is less than 2.1 m10, the effect of improving the strength is weak. If it exceeds 'o', the life of the stain pond will be shortened due to the large amount of self-discharge. By adding XAs, the crystal grains are made finer and the strength is increased as in the above example, or if it is less than 0.15 m10, the crystal grains are coarsened and the corrosion resistance is significantly inferior. Also 0.25 rrV'.

If it exceeds this, the strength tends to decrease.

In addition, the method of the present invention heat-treats and rapidly cools the above-mentioned alloy to improve its mechanical strength, which can be used as a storage battery substrate.
．． 51 History Questions - It is possible to have a proof strength of 2 or more.

Therefore, the heat treatment temperature was limited to a range of 230° to 240°C, but if the temperature was lower than 230°C, the strength would improve, but the strength would be 7.5 to 9f.
It is not possible to reach a yield strength of 1 mm, and if the temperature exceeds 240°C, it cannot be heated to a temperature close to the melting point of the lead alloy.

Note that although the heat treatment time was limited to 5 to 20 minutes, if it is less than 5 minutes, the effect cannot be achieved, and if it is more than 20 minutes, the crystal grains become large and coarse, resulting in a decrease in corrosion resistance.

The reason why the quenching source is limited to 0° to 40°C is that if the temperature exceeds 40°C, the quenching effect is weak and the substrate cannot be hardened. Next, examples of the method of the present invention will be described.

Examples (1) to (2) 2.4 m7'o Sb -0,i5 m7'o A
Continuously cast and rolled material with a composition of s -Pl+ was heated at 210°C.
(Comparative example (1)), 220°C (Comparative example (2)), 230
°C (Example (1)), 240 °C (Example (2)),
After heat treatment at 247° C. (Comparative Example (3)) for 10 minutes, the substrates were rapidly cooled in water at 10° C. to obtain a substrate of the present invention and a comparative example substrate.

The results of measuring the yield strength as mechanical strength of the substrate obtained in this manner are shown in FIG.

As is clear from Fig. 1, the yield strength of the substrate of the present invention is 7,5.
It showed a value higher than kyfvun and was able to be used as a 1-Ikegawa substrate. On the other hand, the comparison board 7.
It could not reach 5kpf 5m-2 and could not be used as a storage battery substrate.

In addition, when the above-mentioned rolled material was not heat-treated, the yield strength was extremely low and was only 2.0 to 9 fnrm-2. Also, comparative example (3
), there was a risk that the rolled material would melt if the heat treatment was performed at a high temperature.

Examples (3) to (4) The rolled material in Example (1) was heat treated at 230°C for 10 minutes, and then heated at 10°C (Example (3)) and 30°C.
'C (Example (4)), 50°C (Comparative Example (4)), and 80°C (Comparative Example (5)) were put into water and quenched to obtain a substrate of the present invention and a comparative example substrate.

The yield strength of the thus obtained substrates of the present invention and comparative substrates was measured, and the results were as shown in FIG.

As is clear from Figure 2, the yield strength of the substrate of the present invention is 7-5 to 9.
It showed a value of fnnn-2 or higher and could be used satisfactorily as a storage battery substrate. On the other hand, the comparative example board had 7.5
It could not reach 9fm-2 and could not be used as a storage battery substrate.

As detailed above and as described in Section 7'j, the method of the present invention has excellent mechanical strength, so it does not elongate even after repeated charging and discharging cycles, and therefore, even when the storage battery is used for a long period of time, it does not cause short circuits. have an effect.

[Brief explanation of drawings]

FIG. 1 is a curve diagram showing the relationship between heat treatment temperature and yield strength in the method of the present invention, and FIG. 2 is a curve diagram showing the relationship between quenching temperature and yield strength in the method of the present invention. Applicant's representative Patent attorney Takehiko Suzue (Pyama°↓5M
) rl protection (zJJJ” '+6M) 17 phJ procedural amendments Showa Chi September 6th and 7th Mr. Kazuo Wakasugi, Commissioner of the Patent Office■, Indication of the case Patent application No. 116509 No. 116509 of 1988 2. Name of the invention: Lead acid ↑ Toso M 21 (Manufacturing method of board 3, relationship with the case of the person making the amendment Special g = 111.1 Published by Uto (538') Urashi Ichiike Co., Ltd. 4, Agent 6, No. of the amendment ] Specification 7, Contents of amendment (11 In the specification, page 2, line 10, "sp" is corrected to rsbJ.

Claims (1)

[Claims] Sb manufactured by continuous casting and rolling 2.1 to 4.5 m
10, As Ool 5~0.2' 5 rrVl
o, 230 before or after machining, such as punching or expanding a rolled lead alloy plate consisting of the remainder Pb.
After heat treatment at °~240℃ for 5~20 minutes 00~40
A method for manufacturing a lead-acid battery substrate, characterized by rapidly cooling it in water at ℃.