Background
Copper and its alloy have high strength, good corrosion resistance and antimicrobial corrosion, so that they are widely used in the fields of ship manufacture, ocean engineering, seawater chemical engineering, etc., and are mainly used in ship shells, various wires, pump bodies, valve bodies, ship propellers, seawater desalination, ship condenser pipes, etc. But due to the particularities of the ocean, copper and its alloys are often severely corroded.
At present, most of corrosion-resistant copper alloys researched and applied at home and abroad mainly comprise brass, tin bronze, B10(Cu-10Ni-1Fe-1Mn), B30(Cu-30Ni-1Fe-lMn) and the like, however, the service conditions of the corrosion-resistant copper alloys are increasingly severe due to complex and changeable marine conditions, the safety and reliability requirements of key parts are higher and higher, and the traditional corrosion-resistant copper alloys cannot meet the use requirements of high-end fields.
The patent (publication number: CN102776410A, name: a corrosion-resistant copper alloy) discloses a corrosion-resistant copper alloy, which uses a large amount of tin, scandium and titanium with high equivalent and a large amount of low-potential metal materials such as magnesium and zinc, and has complex composition of alloy elements, increased production and synthesis difficulty and limited popularization and application range.
Disclosure of Invention
The invention aims to provide a corrosion-resistant copper alloy, which solves the problem of complex composition of copper alloy elements in the prior art.
The technical scheme adopted by the invention is that the corrosion-resistant copper alloy comprises the following components in percentage by mass: 6-8% of Ni, 3-7% of Al, 1-1.6% of Fe, 0.4-1% of Mn and 0.032-0.045% of misch metal; the balance of Cu, the mixed rare earth is a mixture of La and Ce, and the percentage content of La is 35-45%.
The invention is also characterized in that:
fe. The total percentage of Mn is 2%.
Another object of the present invention is to provide a corrosion-resistant copper alloy, which solves the problem of complex composition of copper alloy elements in the prior art.
The other technical scheme adopted by the invention is that the preparation method of the corrosion-resistant copper alloy comprises the following steps:
step 1, pretreating an electrolytic copper plate, an electrolytic nickel plate, an aluminum plate, a copper-iron intermediate alloy, a copper-manganese intermediate alloy and mixed rare earth, wherein the mixed rare earth is a mixture of La and Ce;
step 2, weighing the pretreated electrolytic copper plate, electrolytic nickel plate, aluminum plate, copper-iron intermediate alloy, copper-manganese intermediate alloy and misch metal, wherein the components comprise, by mass, 6-8% of Ni, 3-7% of Al, 1-1.6% of Fe, 0.4-1% of Mn and 0.032-0.045% of misch metal, the balance being Cu, and the percentage content of La is 35-45%;
step 3, sequentially putting an electrolytic copper plate, an electrolytic nickel plate, a copper-iron intermediate alloy, a copper-manganese intermediate alloy and mixed rare earth into a smelting furnace for primary smelting, and adding an aluminum plate into the smelting furnace for secondary smelting after smelting and deslagging;
step 4, when the melt after the secondary smelting reaches the centrifugal casting condition, pouring the melt into a centrifugal casting machine for cooling and solidifying into a blank, and processing to obtain a corrosion-resistant copper alloy cast ingot;
and 5, firstly, placing the corrosion-resistant copper alloy ingot in a resistance furnace for heating and heat preservation, and then placing the corrosion-resistant copper alloy ingot after heating and heat preservation into an extrusion die for hot extrusion deformation processing to obtain the corrosion-resistant copper alloy.
The step 3 comprises the following specific steps:
firstly, sequentially putting an electrolytic copper plate and an electrolytic nickel plate into a smelting furnace to be smelted to obtain first alloy liquid, and then adding a covering agent to cover the first alloy liquid; when the temperature reaches 1150-1200 ℃, sequentially adding a copper-iron intermediate alloy, a copper-manganese intermediate alloy and a misch metal to finish one-time smelting, and adding the next one after each raw material is molten in the feeding process; after the temperature is raised to 1250-1300 ℃, adding an aluminum plate into the smelting furnace after smelting and deslagging, and uniformly stirring for secondary smelting; and adding a deoxidizer in the primary smelting and the secondary smelting, wherein the time of the primary smelting and the secondary smelting is 35-45 min.
The covering agent is one or a mixture of calcined charcoal and plant ash.
The deoxidizer is magnesium or phosphorus copper, and the dosage of the deoxidizer is 0.6-1.2% of the total weight of the melt.
In the step 4: the centrifugal casting condition is that the melt after secondary smelting reaches 1250-1300 ℃, no scum appears on the surface of the melt, and the melt on the surface is pulled open to form a mirror surface.
The preheating temperature of the casting mold of the centrifugal casting machine is 300-450 ℃, the pouring temperature is 1250-.
The heating and heat preservation temperature in the resistance furnace is 1000-1100 ℃, and the heat preservation time is 1-1.5 h; the preheating temperature of the extrusion die is 500-550 ℃.
The invention has the beneficial effects that:
according to the corrosion-resistant copper alloy, the Ni element can improve the corrosion potential and passivation capability and enhance the corrosion resistance of the alloy; al can form a tough and compact protective film on the surface of the alloy, so that the surface activity is reduced, and the erosion resistance of the alloy is enhanced; fe. Mn can obviously improve the strength and the impact corrosion resistance, and W isFe+WMn2%, the alloy strength and the corrosion resistance are improved optimally; the rare earth can purify the alloy matrix, reduce impurities, refine alloy grains, inhibit the diffusion of copper ions in an oxide layer, reduce the corrosion rate of the alloy and improve the corrosion resistance. According to the preparation method of the corrosion-resistant copper alloy, the obtained corrosion-resistant copper alloy is uniform in structure and components and few in as-cast state defects, and the problems that the traditional corrosion-resistant copper alloy is complex in elements and high in production cost are solved; by utilizing the synergistic effect of various microalloyed elements, the novel high-strength corrosion-resistant copper alloy with low Ni content (Al replaces a small amount of Ni), excellent mechanical property and excellent corrosion resistance is obtained.
Detailed Description
The present invention will be described in detail with reference to the following embodiments.
The corrosion-resistant copper alloy comprises the following components in percentage by mass: 6-8% of Ni, 3-7% of Al, 1-1.6% of Fe, 0.4-1% of Mn and 0.032-0.045% of misch metal; the balance of Cu, the mixed rare earth is a mixture of La and Ce, and the percentage content of La is 35-45%. Fe. The total percentage of Mn is 2%.
A preparation method of a corrosion-resistant copper alloy specifically comprises the following steps:
step 1, carrying out corresponding oil removal, rust removal and drying treatment on an electrolytic copper plate, an electrolytic nickel plate, an aluminum plate, a copper-iron intermediate alloy, a copper-manganese intermediate alloy and mixed rare earth; the mixed rare earth is a mixture of La and Ce;
step 2, weighing the pretreated electrolytic copper plate, electrolytic nickel plate, aluminum plate, copper-iron intermediate alloy, copper-manganese intermediate alloy and misch metal, wherein the components comprise, by mass, 6-8% of Ni, 3-7% of Al, 1-1.6% of Fe, 0.4-1% of Mn and 0.032-0.045% of misch metal, and the balance of Cu and inevitable impurity components, and the percentage content of La is 35-45%;
step 3, in a micro-oxidation atmosphere, sequentially putting an electrolytic copper plate and an electrolytic nickel plate into a smelting furnace to be smelted to obtain first alloy liquid, and then adding calcined charcoal and plant ash which are dried at about 200 ℃ to cover the first alloy liquid so as to isolate most air and reduce oxidation in the smelting process; when the temperature reaches 1150-1200 ℃, adding a copper-iron intermediate alloy, a copper-manganese intermediate alloy and mixed rare earth wrapped by copper foil in sequence to finish one-time smelting, and adding the next one after each raw material is molten in the feeding process; after the temperature is raised to 1250-1300 ℃, adding an aluminum plate into the smelting furnace after smelting and deslagging, uniformly stirring, and carrying out secondary smelting to obtain a second alloy liquid; the time of primary smelting and secondary smelting is 35-45 min, and a deoxidizer is added in the primary smelting and secondary smelting processes. And in the whole smelting process, the graphite rods are selected for uniform stirring, and the slag removing rods are used for removing slag.
The deoxidizer is magnesium or phosphorus copper, and the dosage of the deoxidizer is 0.6-1.2% of the weight of the second alloy liquid.
Step 4, preheating the casting mold to 300-450 ℃ in advance, when the melt after secondary smelting reaches 1250-1300 ℃, no floating slag appears on the surface of the melt and the surface melt is in a mirror surface shape after being pulled open, standing for 2-3 min, and then pouring the second alloy liquid into a centrifugal casting machine with water cooling through a pouring ladle, wherein the pouring temperature of the centrifugal casting machine is 1250-1300 ℃, and the rotating speed of the centrifugal machine is 1150-1250 rad/min; and (3) cooling the casting mold by introducing water, spraying cooling water on the annular outer wall of the casting mold, cooling and solidifying the casting mold into a blank, and performing turning processing and other treatment to obtain the corrosion-resistant copper alloy ingot.
Step 5, placing the corrosion-resistant copper alloy ingot in a box-type resistance furnace at the temperature of 1000-1100 ℃ for heating and heat preservation for 1-1.5 h; and then preheating an extrusion die to 500-550 ℃, and putting the corrosion-resistant copper alloy ingot after heating and heat preservation into the extrusion die for hot extrusion deformation processing to obtain the corrosion-resistant copper alloy. The lubricant used in the extrusion die is asphalt or a graphite engine oil mixture.
Example 1
Step 1, carrying out corresponding oil removal, rust removal and drying treatment on an electrolytic copper plate, an electrolytic nickel plate, an aluminum plate, a copper-iron intermediate alloy, a copper-manganese intermediate alloy and mixed rare earth; the mixed rare earth is a mixture of La and Ce;
step 2, weighing the pretreated electrolytic copper plate, electrolytic nickel plate, aluminum plate, copper-iron intermediate alloy, copper-manganese intermediate alloy and misch metal, wherein the components comprise, by mass, Ni 7%, Al 3%, Fe 1.2%, Mn 0.8% and misch metal 0.032%, and the balance of Cu and inevitable impurity components, and the percentage content of La is 35%;
step 3, in a micro-oxidation atmosphere, sequentially putting an electrolytic copper plate and an electrolytic nickel plate into a smelting furnace to be smelted to obtain a first alloy liquid, and then adding a mixture of calcined charcoal and plant ash which are dried at about 200 ℃ to cover the first alloy liquid; when the temperature reaches 1150 ℃, adding the copper-iron intermediate alloy, the copper-manganese intermediate alloy and the mixed rare earth wrapped by the copper foil in sequence to finish primary smelting; after the temperature is raised to 1250 ℃, adding an aluminum plate into the smelting furnace after smelting and deslagging, and uniformly stirring for secondary smelting to obtain a second alloy liquid; the time of primary smelting and secondary smelting is 35min, magnesium is added as a deoxidizer in the primary smelting and secondary smelting processes, and the dosage of the magnesium is 0.6 percent of the weight of the second alloy liquid.
Step 4, preheating the casting mold to 300 ℃ in advance, when the melt after secondary smelting reaches 1250 ℃, no scum appears on the surface of the melt and the melt on the surface is in a mirror surface shape, standing for 2min, and then pouring the second alloy liquid into a water-cooled centrifugal casting machine through a pouring ladle, wherein the pouring temperature of the centrifugal casting machine is 1250 ℃, and the rotating speed of the centrifugal machine is 1150 rad/min; and (3) cooling the casting mold by introducing water, spraying cooling water on the annular outer wall of the casting mold, cooling and solidifying the casting mold into a blank, and performing turning processing and other treatment to obtain the corrosion-resistant copper alloy ingot.
Step 5, putting the corrosion-resistant copper alloy ingot in a box-type resistance furnace at 1000 ℃ for heating and heat preservation for 1 h; and then preheating an extrusion die to 500 ℃, and putting the corrosion-resistant copper alloy cast ingot subjected to heating and heat preservation into the extrusion die for hot extrusion deformation processing to obtain the corrosion-resistant copper alloy. The lubricant used in the extrusion die is a graphite engine oil mixture.
Example 2
Step 1, carrying out corresponding oil removal, rust removal and drying treatment on an electrolytic copper plate, an electrolytic nickel plate, an aluminum plate, a copper-iron intermediate alloy, a copper-manganese intermediate alloy and mixed rare earth; the mixed rare earth is a mixture of La and Ce;
step 2, weighing the pretreated electrolytic copper plate, electrolytic nickel plate, aluminum plate, copper-iron intermediate alloy, copper-manganese intermediate alloy and misch metal, wherein the components comprise, by mass, Ni 7%, Al 5%, Fe 1.2%, Mn 0.8% and misch metal 0.045%, and the balance of Cu and inevitable impurity components, and the percentage content of La is 45%;
step 3, in a micro-oxidation atmosphere, sequentially putting an electrolytic copper plate and an electrolytic nickel plate into a smelting furnace to be smelted to obtain a first alloy liquid, and then adding a mixture of calcined charcoal and plant ash which are dried at about 200 ℃ to cover the first alloy liquid; when the temperature reaches 1180 ℃, adding the copper-iron intermediate alloy, the copper-manganese intermediate alloy and the mixed rare earth wrapped by the copper foil in sequence to finish primary smelting; after the temperature is raised to 1280 ℃, adding an aluminum plate into the smelting furnace after smelting and deslagging, uniformly stirring, and carrying out secondary smelting to obtain a second alloy liquid; the time of primary smelting and secondary smelting is 45min, magnesium is added as a deoxidizer in the primary smelting and secondary smelting processes, and the dosage of the magnesium is 1.2 percent of the weight of the second alloy liquid.
Step 4, preheating the casting mold to 450 ℃ in advance, when the melt after secondary smelting reaches 1280 ℃, no scum appears on the surface of the melt and the surface melt is in a mirror surface shape after being pulled open, and after standing for 3min, pouring the second alloy liquid into a water-cooled centrifugal casting machine through a pouring ladle, wherein the pouring temperature of the centrifugal casting machine is 1280 ℃, and the rotating speed of the centrifugal machine is 1250 rad/min; and (3) cooling the casting mold by introducing water, spraying cooling water on the annular outer wall of the casting mold, cooling and solidifying the casting mold into a blank, and performing turning processing and other treatment to obtain the corrosion-resistant copper alloy ingot.
Step 5, putting the corrosion-resistant copper alloy ingot in a box-type resistance furnace at 1100 ℃ for heating and heat preservation for 1.5 h; and then preheating an extrusion die to 550 ℃, and putting the corrosion-resistant copper alloy cast ingot after heating and heat preservation into the extrusion die for hot extrusion deformation processing to obtain the corrosion-resistant copper alloy. The lubricant used in the extrusion die is a graphite engine oil mixture.
Example 3
Step 1, carrying out corresponding oil removal, rust removal and drying treatment on an electrolytic copper plate, an electrolytic nickel plate, an aluminum plate, a copper-iron intermediate alloy, a copper-manganese intermediate alloy and mixed rare earth; the mixed rare earth is a mixture of La and Ce;
step 2, weighing the pretreated electrolytic copper plate, electrolytic nickel plate, aluminum plate, copper-iron intermediate alloy, copper-manganese intermediate alloy and misch metal, wherein the components comprise, by mass, Ni 7%, Al 7%, Fe 1.2%, Mn 0.8% and misch metal 0.038%, and the balance of Cu and inevitable impurity components, and the percentage content of La is 40%;
step 3, in a micro-oxidation atmosphere, sequentially putting an electrolytic copper plate and an electrolytic nickel plate into a smelting furnace to be smelted to obtain a first alloy liquid, and then adding a mixture of calcined charcoal and plant ash which are dried at about 200 ℃ to cover the first alloy liquid; when the temperature reaches 1200 ℃, adding the copper-iron intermediate alloy, the copper-manganese intermediate alloy and the mixed rare earth wrapped by the copper foil in sequence to finish primary smelting; after the temperature is raised to 1300 ℃, adding an aluminum plate into the smelting furnace after smelting and deslagging, and uniformly stirring for secondary smelting to obtain a second alloy liquid; the time of primary smelting and secondary smelting is 40min, magnesium is added as a deoxidizer in the primary smelting and secondary smelting processes, and the dosage of the magnesium is 0.8 percent of the weight of the second alloy liquid.
Step 4, preheating the casting mold to 400 ℃ in advance, when the melt after secondary smelting reaches 1300 ℃, no scum appears on the surface of the melt and the melt on the surface of the melt is in a mirror surface shape, standing for 2min, and then pouring the second alloy liquid into a water-cooled centrifugal casting machine through a pouring ladle, wherein the pouring temperature of the centrifugal casting machine is 1300 ℃, and the rotating speed of the centrifugal machine is 1200 rad/min; and (3) cooling the casting mold by introducing water, spraying cooling water on the annular outer wall of the casting mold, cooling and solidifying the casting mold into a blank, and performing turning processing and other treatment to obtain the corrosion-resistant copper alloy ingot.
Step 5, putting the corrosion-resistant copper alloy cast ingot into a box-type resistance furnace at 1075 ℃ for heating and heat preservation for 1.2 h; and then preheating an extrusion die to 550 ℃, and putting the corrosion-resistant copper alloy cast ingot after heating and heat preservation into the extrusion die for hot extrusion deformation processing to obtain the corrosion-resistant copper alloy. The lubricant used in the extrusion die is a graphite engine oil mixture.
The high-strength corrosion-resistant copper alloy prepared in the embodiments 1 to 3 is subjected to mechanical property and corrosion resistance tests, and the test results are as follows:
numbering
|
Corrosion rate, mm/a
|
Tensile strength, MPa
|
Elongation percentage
|
Example 1
|
0.0032
|
705
|
28
|
Example 2
|
0.0035
|
711
|
25
|
Example 3
|
0.0024
|
724
|
27 |
Through the mode, the tensile strength of the corrosion-resistant copper alloy is over 700MPa, the elongation is over 20 percent, and the alloy has good mechanical property; the corrosion-resistant copper alloy has excellent corrosion resistance, the corrosion rate of 240h is lower than 0.004mm/a, and the corrosion-resistant copper alloy has the advantages of uniform tissue components, few as-cast defects, relatively simple alloy elements, low cost, excellent mechanical property, excellent corrosion resistance and the like, and meets the use requirements of the corrosion-resistant copper alloy under severe service conditions.