CN112342428A

CN112342428A - DZR copper and preparation method thereof

Info

Publication number: CN112342428A
Application number: CN202011152089.5A
Authority: CN
Inventors: 伍海英
Original assignee: Kaiping Dachang Copper Material Co ltd
Current assignee: Kaiping Dachang Copper Material Co ltd
Priority date: 2020-10-23
Filing date: 2020-10-23
Publication date: 2021-02-09

Abstract

The invention discloses DZR copper, which consists of the following components in percentage by mass: 61.5 to 63.5 percent of Cu, less than 0.18 percent of Pb, 0.03 to 0.15 percent of Fe, less than or equal to 0.15 percent of Sn, 0.6 to 0.8 percent of Al, less than 0.15 percent of Ni, less than 0.1 percent of Sb, 0.09 to 0.17 percent of As, less than 0.01 percent of Bi, less than 0.03 percent of other impurities and the balance of Zn. The inventor finally optimizes and screens the formula by adjusting the contents of copper, arsenic and zinc elements in DZR copper, adding iron and aluminum elements and controlling the content of impurity metal elements which have larger influence. The DZR copper with the formula has excellent dezincification resistance and good quality stability.

Description

DZR copper and preparation method thereof

Technical Field

The invention belongs to the technical field of metallurgical materials, and particularly relates to DZR copper and a preparation method thereof.

Background

Stress corrosion and dealloying corrosion are the most predominant corrosion of brass during long-term use; the most typical corrosion of copper alloy is the corrosion of zinc element, which is the possibility of carrying the precursor away by water, and the component contacting with water extends from the surface to the inside to risk the occurrence of cellular micro-cavities, thereby affecting the service life of the brass product. The debinding corrosion may occur simultaneously with the stress corrosion process or may occur separately.

Dezincification takes two forms: one is the layered falling type dezincification which is in a uniform corrosion form and has small relative harm to the use of materials; the other is deep bolt-shaped development type dezincification which is in a pit-shaped corrosion form, so that the strength of the material is obviously reduced, and the harmfulness is larger.

The DZR copper is commonly called corrosion-resistant brass, and has good inhibition effect on the dezincification process because the DZR copper contains a certain amount of arsenic (As) in alloy elements, and has good corrosion resistance in both fresh water and seawater. However, the dezincification resistance and quality stability of the conventional DZR copper are still to be improved.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide DZR copper and a preparation method thereof.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the DZR copper comprises the following components in percentage by mass: 61.5 to 63.5 percent of Cu, less than 0.18 percent of Pb, 0.03 to 0.15 percent of Fe, less than or equal to 0.15 percent of Sn, 0.6 to 0.8 percent of Al, less than 0.15 percent of Ni, less than 0.1 percent of Sb, 0.09 to 0.17 percent of As, less than 0.01 percent of Bi, less than 0.03 percent of other impurities and the balance of Zn.

The inventor finally optimizes and screens the formula by adjusting the contents of copper, arsenic and zinc elements in DZR copper, adding iron and aluminum elements and controlling the content of impurity metal elements which have larger influence. The DZR copper with the formula has excellent dezincification resistance and good quality stability.

In the formula, if the content of Cu is lower than 61.5%, the dezincification resistance effect of brass is poor, and zinc is easy to fall off; if the Cu content is more than 63.5%, the casting is affected, the fluidity is not good, and shrinkage and leakage are easily generated. The content of Pb is controlled not to exceed 0.18 percent, so that the product can meet the national standard requirement and the water tap and other fieldsThe usage requirements of the domain. If the content of Fe is less than 0.03%, the brass cannot be refined; if the Fe content is more than 0.15%, impurity spots may be generated after the casting is polished. If the content of Sn is more than 0.15%, pores and impurity points are generated in the casting. The addition of Al can increase the fluidity of the copper liquid, form alumina on the surface of the copper liquid and prevent zinc volatilization, and when the content of Cu is 61.5-63.5%, the content of Al of 0.6-0.8% can make the above effect better. The Ni content is less than 0.15%, which can make the brass structure good and reduce the polishing impurity. The content of Sb is less than 0.1%, so that the quality stability of the brass is better. 0.09% -0.17% of As is added into brass to prevent the dezincification of the brass, so that a firm protective film is formed on the surface of the brass product, and the corrosion resistance of the brass is improved. If the As is excessive, the brittle compound Cu is generated in brass₃As is distributed on grain boundaries, and the plasticity of brass is reduced. Excessive Bi can cause a continuous brittle film to be distributed on a brass crystal boundary, so that hot brittleness and cold brittleness are generated, and the damage to brass is great. The invention controls the content of other impurities to be below 0.03 percent, and can ensure the quality stability of the brass castings.

Preferably, the DZR copper consists of the following components in percentage by mass: 62.42 percent of Cu, less than 0.18 percent of Pb, 0.05 percent of Fe, less than or equal to 0.15 percent of Sn, 0.62 percent of Al, less than 0.15 percent of Ni, less than 0.1 percent of Sb, 0.129 percent of As, less than 0.01 percent of Bi, less than 0.03 percent of other impurities and the balance of Zn.

The invention also provides a preparation method of the DZR copper, which comprises the following steps:

(1) preparing materials: weighing red copper with the purity of more than or equal to 99.9%, 0# zinc ingot, aluminum ingot, lead ingot, alloy iron, aluminum boron alloy, copper arsenic alloy, 65# brass scrap and A-grade brass bran according to the formula components;

(2) smelting: putting prepared raw materials into a smelting furnace in sequence for smelting, putting 65# brass rim charge, 1/2 zinc ingots, 2/3 aluminum ingots, alloy iron and aluminum boron alloy into the smelting furnace for melting, adding a slag remover to rake out ash slag after melting, then putting A-grade brass brans into the smelting furnace for melting, adding the slag remover to rake out ash slag after melting, then putting red copper into the smelting furnace for melting, finally adding the rest zinc ingots, aluminum ingots, lead ingots and copper-arsenic alloy for melting, adding a refining agent after melting, heating to 980-1050 ℃, keeping the temperature for 25-35 min for degassing and impurity removal, keeping copper water in the furnace rolling uniformly in the heating process, and heating the smelting furnace to 1080 ℃ to cast copper ingots;

(3) molding and polishing: and naturally cooling the copper ingot, then polishing the surface of the copper ingot to make the surface smooth, and packaging the copper ingot into a warehouse to obtain the DZR copper.

Preferably, in the step (2), the time from the raw material feeding to the discharging is controlled to be 110-130 minutes. Controlling the time ensures that the components are fully alloyed.

In the preparation method, the selection of raw materials, the time control and the feeding sequence are the key for controlling the impurity content in the DZR copper, and if the raw materials are not fed according to the feeding sequence, the impurity content of the product is higher, so that the mirror polishing effect of the DZR copper is influenced. In addition, in the smelting process, the crystal grains of the DZR copper can be made finer and more uniform by keeping the copper water in the furnace to roll uniformly in the temperature rising process.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, the DZR copper with better dezincification resistance and better quality stability is obtained by optimizing the formula and the preparation method of the DZR copper.

Drawings

FIG. 1 is a metallographic microscopic image of DZR copper of example 1 after being subjected to a dezincification test;

fig. 2 is a metallographic microscopic image of the DZR copper of comparative example 1 after being subjected to a dezincification test.

Detailed Description

The technical solutions of the present invention will be further described with reference to the following embodiments and the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The starting materials used in the examples are commercially available and the procedures used are conventional in the art unless otherwise specified. Wherein, the slag removing agent and the refining agent used in the embodiment are the slag removing agent and the refining agent which are conventionally used in the preparation of DZR copper.

Example 1

The DZR copper comprises the following components in percentage by mass: 62.42 percent of Cu, 0.04 percent of Pb, 0.05 percent of Fe, 0.04 percent of Sn, 0.62 percent of Al, 0.03 percent of Ni, 0.129 percent of As and the balance of Zn.

The preparation method of the DZR copper comprises the following steps:

(1) preparing materials: weighing red copper (with the purity of 99.9%), 0# zinc ingot, aluminum ingot, lead ingot, alloy iron, aluminum boron alloy, copper arsenic alloy, 65# brass scrap and A-grade brass bran according to the formula components;

(2) smelting: putting prepared raw materials into a smelting furnace for smelting in sequence, putting 65# brass rim charge, 1/2 zinc ingots, 2/3 aluminum ingots, alloy iron and aluminum boron alloy into the smelting furnace for melting, adding a slag remover to rake out ash slag after melting, then putting A-grade brass brans into the smelting furnace for melting, adding the slag remover to rake out ash slag after melting, then putting red copper into the smelting furnace for melting, finally adding the rest zinc ingots, aluminum ingots, lead ingots and copper arsenic alloy for melting, adding a refining agent after melting, heating to 1030-1050 ℃, keeping the temperature for 30min for degassing and impurity removal, keeping copper water in the furnace to roll uniformly in the heating process, and heating the smelting furnace to 1080 ℃ to cast copper ingots by the copper water. In the step, the time from the feeding of the raw materials to the tapping is controlled to be 120 minutes, the feeding and melting of the raw materials are carried out for 90 minutes, and the refining treatment is carried out for 30 minutes.

Comparative example 1

The DZR copper comprises the following components in percentage by mass: cu 59.99%, Pb 2.54%, Fe 0.50%, Sn 0.97%, Al 0.02%, Ni 0.40%, As 0.17%, and the balance of Zn.

The preparation method of the DZR copper is the same as that of example 1.

Performance testing

And (3) testing conditions are as follows: the DZR copper sample prepared in example 1 is placed in a copper chloride test solution at 75 ℃, submerged for 24 hours, taken out and dried, then embedded, ground and polished perpendicular to the test surface, and the dezincification depth of the test surface is observed and measured under a metallographic microscope. The test results are shown in the following table and attached figures 1-2:

note: the test value of the average dezincification depth is qualified below 100.

From the test results in the table above, it can be seen that compared with comparative example 1, the DZR copper of example 1 of the present invention has superior dezincification resistance and good quality stability.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. The DZR copper is characterized by comprising the following components in percentage by mass: cu61.5-63.5%, Pb less than 0.18%, Fe 0.03-0.15%, Sn less than or equal to 0.15%, Al 0.6-0.8%, Ni less than 0.15%, Sb less than 0.1%, As 0.09-0.17%, Bi less than 0.01%, other impurities less than 0.03%, and the balance of Zn.

2. The DZR copper of claim 1, consisting of the following components in mass percent: 62.42 percent of Cu, less than 0.18 percent of Pb, 0.05 percent of Fe, less than or equal to 0.15 percent of Sn, 0.62 percent of Al, less than 0.15 percent of Ni, less than 0.1 percent of Sb, 0.129 percent of As, less than 0.01 percent of Bi, less than 0.03 percent of other impurities and the balance of Zn.

3. The method of preparing DZR copper of claim 1 or 2, comprising the steps of:

4. The method for producing DZR copper according to claim 3, wherein in the step (2), the time from the charging of the raw material to the discharging is controlled to be 110 to 130 minutes.