Low-lead brass alloy

Abstract

The invention relates to a low-lead brass alloy, comprising: by the total weight of the brass alloy, 62.5-63 wt % copper, 0.16-0.24 wt % lead, 0-0.02 wt % antimony, 0-0.01 wt % magnesium, 0-0.2 wt % tin, 0.0005-0.0009 wt % boron, 0.55-0.7 wt % aluminum, 0.05-0.15 wt % iron, 0-0.15 wt % nickel, 0.09-0.12 wt % arsenic, 0-0.005 wt % zirconium, 0-0.01 wt % impurities, and a balance of zinc.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the priority benefit of Chinese patent application No.201410282838.4, filed on Jun. 23, 2014. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of specification.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The invention relates to a low-lead brass alloy.[0004]2. Background of the Invention[0005]Copper has excellent electrical conductivity and environmental friendliness, and bacteria harmful to the human can't survive on its surface. Other elements are added into copper, so as to improve its performance. For example, the addition of lead into the brass alloy containing copper and zinc significantly improves the cutting performance of the brass. However, lead has a destructive effect on the human health and ecological balance. It is also a trend around the world that there are increasing restrictions on the application of lead-containin...

AI Technical Summary

Benefits of technology

[0008]It is an object of the invention to provide a brass alloy which exhibits excellent performance like tensile strength, elongation rate, dezincification resistance and cutting performance, which is suitable for cutting processed products that require high strength, wear resistance and waterlogging resistance. The brass alloy of the invention can securely replace the alloy copper with a high lead content, and can completely meet the demands about restrictions on lead-containing products in the development of human society.

[0011]In the inventive product 1, the content of lead is reduced to 0.24 wt % or less, the content of copper is maintained at 62.5-63 wt %, and a trace amount of aluminum is added to increase cutting performance of the brass alloy. Meanwhile, since aluminum has a higher tendency to be ionized on the surface of the alloy than zinc, and preferentially reacts with oxygen in a corrosive gas or solution to develop a dense protection film of aluminum oxide on the surface of the alloy, thus increasing corrosion resistance and dezincification resistance of the brass alloy in the severe environment. Besides, aluminum can increase cast flowability of the alloy, so that the alloy exhibits a significant improvement in strength and hardness. In order to make a better use of the above effects, the content of aluminum is 0.55-0.7 wt % by the total weight of the brass alloy.

[0012]Preferably, the inventive product 1 further comprises: one or more elements selected from the group consisting of 0-0.02 wt % antimony, 0-0.2 wt % tin, 0-0.01 wt % magnesium, and 0.09-0.12 wt % arsenic by the total weight of the brass alloy. All of these elements can to a certain degree increase cutting performance of the brass alloy. The addition of antimony and tin can significantly increase strength of the alloy, and improve its plasticity and corrosion resistance. A trace amount of arsenic can increase dezincification resistance of the alloy. However, a high content of arsenic is not favorable, since it will decrease the thermal forgeability and squeezing performance of the alloy.

[0013]More preferably, the above-mentioned inventive product further comprises one or more elements selected from the group consisting of 0.0005-0.0009 wt % boron, 0.05-0.15 wt % iron, 0-0.15 wt % nickel, and 0-0.005 wt % zirconium by the total weight of the brass alloy. Boron can increase corrosion resistance of the brass alloy, and can also prevent dezincification. Iron can enhance toughness of the brass alloy. Nickel can not only prevent the brass alloy from rusting, but also can form intermetallic compounds among metals in the alloy, which uniformly precipitate in the matrix, thus increasing wear resistance and strength of the alloy. Zirconium can help to refine grains, thus increasing casting performance of the brass alloy.

Problems solved by technology

Copper has excellent electrical conductivity and environmental friendliness, and bacteria harmful to the human can't survive on its surface.

However, lead has a destructive effect on the human health and ecological balance.

In addition, the environmental problem is increasingly outstanding, and the working environment is becoming more serious.

As a result, the surface strength of brass products is reduced, and the brass tube may even perforate.

This greatly reduces the lifetime of brass products and causes problems in application.

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