TWI500783B - Brass alloy and its manufacturing method - Google Patents

Description

Brass alloy and its manufacturing method

This invention relates to a brass alloy, and more particularly to a lead-free, free-cutting, dezincification-resistant brass alloy.

Generally, as a processing brass, the proportion of zinc metal added is 38 to 42%. In order to make brass better processed, there are usually 2 to 3% lead in brass to increase strength and processability. Lead-containing brass has excellent formability (easy to make various shapes), machinability and wear resistance are widely used in various shapes of machined parts, and occupy a large proportion in the copper industry, which is recognized as important in the world. Basic materials. However, lead-containing brass is prone to lead dissolution in solid or gaseous form during production or use. Medical research indicates that lead damages human hematopoiesis and the nervous system, especially children's kidneys and other organs. All countries in the world attach great importance to the pollution caused by lead and the damage caused by the National Sanitation Foundation (NSF), Japanese Industrial Standards (JIS), German Institute of Standardization (Deutsches Institut für Normung eV, DIN) And the European Union's Restriction of Hazardous Substances Directive (RoHS) has been stipulated to limit and prohibit the use of leaded brass.

In addition, when the zinc content in the brass exceeds 20% by weight, dezincification is prone to corrosion, especially when the brass is in contact with high chlorine. In an ion environment, such as a seawater environment, dezincification corrosion is accelerated. Since dezincification can seriously damage the structure of the brass alloy, the surface strength of the brass product is lowered, or even the brass tube is perforated, the service life of the brass product is greatly shortened, and the application problem is caused.

Therefore, there is a need to provide an alloy formulation that can replace lead-containing brass and which is resistant to dezincification corrosion, but which still requires both casting properties, machinability, corrosion resistance, and mechanical properties to solve the aforementioned problems.

It is an object of the present invention to provide a brass alloy which is excellent in dezincification resistance and which does not contain lead.

In order to achieve the above object, the present invention provides a brass alloy having a total weight of 100% by weight, the brass alloy comprising the following components: 60 to 65 wt% of copper, 0.1 to 0.3 wt% of bismuth, 0.25 to 0.5 wt%. The bismuth, the balance of zinc, and the inevitable impurities.

In order to achieve the above object, the present invention further provides a method for producing a brass alloy, comprising the steps of: providing copper and manganese; heating the copper and the manganese, and heating the temperature to between 1100 ° C and 1150 ° C to make copper And forming a copper-manganese alloy melt; reducing the temperature of the copper-manganese alloy melt to between 950 ° C and 1000 ° C; covering a rice husk ash on the surface of the copper-manganese alloy melt; adding zinc to the copper Forming a copper manganese zinc melt in the manganese alloy melt; removing the slag from the copper manganese zinc melt; adding lanthanum, cerium, aluminum and tin to the copper manganese zinc melt to form a molten metal; Increasing the temperature of the molten metal to between 1000 degrees Celsius and 1050 degrees Celsius, adding a copper boron alloy and a phosphor bronze alloy to form a brass alloy solution; and forming the brass alloy solution by casting Brass alloy.

The brass alloy described in the present invention is added to a certain proportion of various metals, and then subjected to a high-frequency melting furnace to produce a mechanical processing property comparable to that of a conventional lead-containing brass, and a good tensile strength and elongation. It is excellent in rate, anti-zinc removal and lead-free. It is suitable for use as a substitute for conventional lead-containing brass alloy materials, such as faucets or bathroom accessories.

The above and other objects, features, and advantages of the present invention will become more apparent from the accompanying drawings.

S100~S116‧‧‧Steps

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart showing a method of manufacturing a brass alloy according to an embodiment of the present invention.

Figure 2 is a photograph of the test results of the cutting properties of a brass alloy.

According to the method for manufacturing a brass alloy according to an embodiment of the present invention, the brass alloy can have mechanical processing properties comparable to conventional lead-containing brass, good tensile strength and elongation, and good resistance to dezincification. It is completely lead-free and is very suitable for use as a substitute for conventional lead-containing brass alloy materials. The brass alloy comprises the following components at a total weight of 100% by weight: 60 to 65 wt% of copper, 0.1 to 0.3 wt% of niobium, 0.25 to 0.5 wt% of niobium, a balance of zinc, and unavoidable impurities. . The brass alloy may further comprise a mixture of aluminum, tin, phosphorus, manganese and boron, and the total content of the mixture is from 0.2 to 2% by weight of the brass alloy. In addition, in production, the unavoidable impurities are brought into the brass alloy due to the purity of the material itself, and the total content of the unavoidable impurities may be 0.1 wt% or less of nickel, 0.1 wt% or less of chromium or 0.1wt% or less iron.

Preferably, the brass alloy of the present invention is composed of only 60 to 65 wt% of copper, 0.1 to 0.3 wt% of rhodium, 0.25 to 0.5 wt% of rhodium, a balance of zinc, and unavoidable impurities. .

In another embodiment, the brass alloy of the present invention has a composition of only 60 to 65 wt% of copper, 0.1 to 0.35 wt% of niobium, 0.15 to 0.5 wt% of niobium, and aluminum, tin, phosphorus, manganese, and A mixture of boron, and the total content of the mixture is composed of 0.2 to 2% by weight of the brass alloy, an equilibrium amount of zinc, and unavoidable impurities.

In another embodiment, the brass alloy of the present invention is 61.5-62.5 wt% copper, 0.15-0.3 wt% niobium, 0.25-0.35 wt% niobium, 0.15-0.25 wt% aluminum, 0.2- 0.4 wt% of manganese, 0.5-0.6 wt% of tin, 0.15-0.2 wt% of phosphorus, 0.002-0.005 wt% of boron, an equilibrium amount of zinc, and unavoidable impurities.

The metallographic structure of the brass alloy of the present invention mainly comprises an α phase, a β phase, and an intermetallic compound which is distributed in the grain boundary or the grain and is soft and brittle, wherein copper and zinc are main elements constituting the 6/4 brass, and The addition of niobium can replace lead as a cutting breakpoint in the tissue. However, if the content of bismuth is too high, thermal cracking is likely to occur during forging. Therefore, in the case of reducing the content, some of the use of bismuth and phosphorus can produce intermetallic compounds with copper to increase machinability and also contribute to dezincification resistance. The addition of elements such as aluminum, tin and manganese also contributes to dezincification resistance and casting fluidity. The addition of boron has the effect of refining crystal grains, dispersing the distribution of intermetallic compounds, and increasing the resistance to dezincification and mechanical properties.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart showing a method of manufacturing a brass alloy according to an embodiment of the present invention. A method of manufacturing a brass alloy, comprising the following steps:

Step S100: providing copper and manganese. In this step, a copper-manganese alloy can be provided as a material for providing the copper and manganese.

Step S102: heating copper and manganese, and heating to between 1100 degrees Celsius and 1150 degrees Celsius, so that copper and manganese form a copper-manganese alloy melt. In this step, the copper-manganese alloy can be added to a high-frequency melting furnace, and melted and heated in a melting furnace, and heated to between 1100 ° C and 1150 ° C. The action is maintained for 30 minutes to melt the copper-manganese alloy. Form a copper-manganese alloy melt. The above action can prevent the liquid melted by copper and manganese from absorbing a large amount of external gas due to too high temperature, resulting in cracking of the formed alloy material.

The high-frequency melting furnace has the characteristics of fast melting rate, high rising temperature, clean and pollution-free, and self-stirring by melting (ie, affected by magnetic lines of force), and the high-frequency melting furnace is lined with a carbonized bismuth graphite crucible to make For the purpose of magnetic conduction.

Step S104: reducing the temperature of the copper-manganese alloy melt to between 950 ° C and 1000 ° C. In this step, when the temperature in the melting furnace is raised to between 1100 °C and 1150 °C for 30 minutes, the power of the high-frequency melting furnace is turned off, and the temperature in the melting furnace is lowered to 950 ° C to 1000 ° C. At the same time, the copper-manganese alloy melt is still in a molten state.

Step S106: covering the surface of the rice husk ash on the copper-manganese alloy melt. In this step, the rice husk ash is covered on the surface of the copper-manganese alloy melt at 950 ° C to 1000 ° C. This action can effectively block the contact of the liquid with the air and prevent the zinc to be added after 950 ° C to 1000 ° C. The high temperature melts between degrees to produce boiling volatilization.

Step S108: adding zinc to the copper-manganese alloy melt to form A copper manganese zinc melt. In this step, zinc is added to the melting furnace, and the copper-manganese alloy melt is sunk to dissolve the zinc and copper-manganese alloy melt to form a copper manganese zinc melt.

Step S110: removing slag from the copper manganese zinc melt. In this step, the copper manganese zinc melt can be stirred and mixed by the magnetic conductive action of the carbonized ruthenium graphite crucible lining, and then the rice husk ash is picked up. Then, the slag removing agent is used for the slag removing operation.

Step S112: adding lanthanum, cerium, aluminum and tin to the copper manganese zinc melt to form a molten metal. In this step, a pure base metal, a pure base metal, a pure aluminum metal or a pure tin metal may be added to the copper manganese zinc melt.

Step S114: raising the temperature of the molten metal to between 1000 ° C and 1050 ° C, and adding a copper boron alloy and a phosphor bronze alloy to form a brass alloy solution. In this step, a copper boron alloy and a phosphor bronze alloy are added to the molten metal.

Step S116: The brass alloy solution is cast out to form a brass alloy. In this step, after uniformly stirring the brass alloy solution, the temperature of the furnace is controlled to be between 1030 degrees Celsius and 1050 degrees Celsius, and finally the brass alloy solution is cast out to produce lead-free, good processing performance and dezincification resistance. Brass alloy with good mechanical properties.

The composition ratio of the materials of the present invention is measured as follows, and the unit is weight percentage (wt%):

The anti-dezincification test results are as follows:

The anti-dezincification corrosion performance test was carried out according to the AS-2345-2006 specification. 12.8 g of copper chloride was added to 1000 C.C deionized water, and the actual measurement 1~5 was placed therein for 24 hours to measure the dezincification depth. According to the above composition ratio and anti-dezincification test results, when the weight percentage of copper metal is more than 60, the average dezincification depth is greatly reduced, especially when the specific gravity of copper metal is 60.5 wt%, the average dezincification The depth is reduced to 80 microns. From the above experiment, it is known that the copper content needs to be 60% or more and a small amount of anti-dezinc alloying element is added to obtain a dezincification depth of 100 μm or less.

Then, 7 sets of experiments were performed, and the specific gravity of each group of brass alloy copper metal was greater than or equal to 60.5 wt% for testing of tensile strength, elongation, dezincification depth and relative cutting rate.

The composition ratio of the materials is measured as follows, and the unit is weight percentage (wt%):

The above material numbers 1 to 7 were tested for tensile strength, elongation, cutting performance and resistance to dezincification corrosion, and the samples were as cast.

Tensile strength and elongation test were carried out in the as-cast form at room temperature. The comparative samples were lead-containing yellow brass of the same specification and the same specification, namely C36000 alloy.

In the cutting performance test, the same tool, the same cutting speed and the same amount of cutting, the cutting speed is 25m/min (m/min), the feed rate is 0.2mm/r (mm/number of cutting edges), and the cutting depth is 0.5mm, the test rod diameter is 20mm, and based on the C36000 alloy material, the relative cutting rate is obtained by measuring the cutting resistance.

Relative cutting rate = cutting resistance of C36000 alloy material / sample cutting resistance.

Detoxification corrosion resistance test is carried out according to AS-2345-2006 specification, adding 12.8 g of copper chloride to 1000 C.C deionized water, and placing material No. 1~7 and C36000 alloy materials for 24 h, to measure It is resistant to dezincification.

The composition ratio of C36000 alloy material is as follows, the unit is weight percentage (wt%):

The tensile strength, elongation, cutting performance and resistance to dezincification corrosion are as follows:

In the above table, the dezincification layer: ◎ represents a dezincification depth of less than 100 μm; ○ represents a dezincification depth of between 100 μm and 200 μm; and ㄨ represents a dezincification depth of more than 200 μm.

In the above table, the relative cutting rate: ◎ represents a relative cutting rate greater than 85%; ○ represents a relative cutting rate greater than 70%.

It can be seen from the above table that when the specific gravity of the copper metal is from 60.05 to 64.03% by weight, when other metals such as lanthanum and cerium are added, the machinability and the small dezincification depth of the C36000 alloy can be obtained. The above 7 sets of experiments were obtained from Figure 2, and the cutting was short. Small cutting represents good machinability

It can be seen from the above that after adding a certain amount of different metals in a certain ratio, a high-frequency melting furnace is used to produce a mechanical processing property comparable to that of a conventional lead-containing brass, and good tensile strength, elongation, and dezincification resistance. Excellent, easy to cut, and lead-free, suitable for use as a replacement for conventional lead-containing brass alloy materials, such as faucets or bathroom accessories.

In the above, it is merely described that the present invention is an embodiment or an embodiment of the technical means for solving the problem, and is not intended to limit the scope of implementation of the present invention. That is, the equivalent changes and modifications made in accordance with the scope of the patent application of the present invention or the scope of the invention are covered by the scope of the invention.

S110~S116‧‧‧Steps

Claims (10)

A brass alloy having a total weight of 100% by weight, the brass alloy comprising the following components: 60 to 65 wt% of copper, 0.1 to 0.3 wt% of niobium, 0.25 to 0.5 wt% of niobium, aluminum, tin, phosphorus a mixture of manganese and boron, the total content of which is 0.2 to 2% by weight of the brass alloy, an equilibrium amount of zinc, and unavoidable impurities. The brass alloy according to claim 1, wherein the total content of the unavoidable impurities is 0.1 wt% or less of nickel, 0.1 wt% or less of chromium or 0.1 wt% or less of iron. A method for manufacturing a brass alloy, comprising the steps of: providing copper and manganese; heating the copper and the manganese to a temperature of between 1100 degrees Celsius and 1150 degrees Celsius to form a copper-manganese alloy of the copper and the manganese Melting; reducing the temperature of the copper-manganese alloy melt to between 950 ° C and 1000 ° C; covering a rice husk ash on the surface of the copper-manganese alloy melt; adding zinc to the copper-manganese alloy melt, and Forming a copper manganese zinc melt; removing the slag from the copper manganese zinc melt; adding lanthanum, cerium, aluminum and tin to the copper manganese zinc melt to form a molten metal; Raising the temperature of the molten metal to between 1000 ° C and 1050 ° C, adding a copper boron alloy and a phosphor bronze alloy to form a brass alloy solution; and casting the brass alloy solution to form the yellow Copper alloy. The method for producing a brass alloy according to claim 3, wherein the step of removing the slag from the copper manganese zinc melt further comprises removing the slag by using a slag removing agent. The method for producing a brass alloy according to claim 3, wherein the operation of raising the temperature of the copper and the manganese and raising the temperature to between 1100 ° C and 1150 ° C for 30 minutes is maintained. The method for producing a brass alloy according to claim 3, wherein the brass alloy is calculated based on a total weight of 100% by weight, and the brass alloy comprises the following components: 60 to 65 wt% of the copper, 0.1~ 0.35 wt% of the niobium, 0.15 to 0.5 wt% of the niobium, a balance of the zinc, and unavoidable impurities. The method for producing a brass alloy according to claim 3, wherein the total content of aluminum, tin, phosphorus, manganese and boron of the brass alloy is 0.2 to 2% by weight of the brass alloy. A method of producing a brass alloy according to claim 3, wherein a copper-manganese alloy is provided as a material for providing the copper and the manganese. A brass alloy having a total weight of 100 wt%, the brass alloy comprising 60 to 65 wt% of copper, 0.1 to 0.35 wt% of niobium, 0.15 to 0.5 wt% of niobium, aluminum, tin, phosphorus, manganese, and a mixture of boron, the total content of which accounts for the yellow 0.2 to 2 wt% of copper alloy, balanced amount of zinc, and unavoidable impurities. A brass alloy having a total weight of 100 wt%, the brass alloy being 61.5-62.5 wt% copper, 0.15-0.3 wt% niobium, 0.25-0.35 wt% niobium, 0.15-0.25 wt% aluminum 0.2-0.4 wt% of manganese, 0.5-0.6 wt% of tin, 0.15-0.2 wt% of phosphorus, 0.002-0.005 wt% of boron, a balance of zinc, and unavoidable impurities.