A kind of aluminium bar and preparation method thereof
Technical field
The present invention relates to the aluminium conductor production technical field, especially relate to a kind of aluminium bar of the aluminium conductor that can pull out high-tensile, high conductivity and prepare the method for this kind aluminium bar.
Background technology
Along with the large-cross section aerial lead that transmitting line adopts is more and more general, to lead and to form the technical requirements of aluminum steel of lead also increasingly high, electric conductivity improves 8 ‰, and tensile strength improves 10%.Generally speaking, the electric conductivity of aluminum steel and tensile strength are the relation of negative correlation, so should improve the electric conductivity of aluminum steel, the tensile strength that improves aluminum steel again has bigger technical difficulty.
The electric conductivity of aluminum steel is relevant with the foreign matter content in the aluminium with tensile strength, and the major impurity in the aluminium is silicon and iron, and their existence can make the tensile strength of aluminium bar increase, but the elongation reduction, resistivity obviously increases.Iron and aluminium can form FeAl
3Phase, silicon are then many in aluminium base to be existed with free ground state, and iron silicon ratio is that w (Fe)/w (Si) value is more little, and resistivity is more little.But as w (Fe)/w (Si)<1 o'clock, aluminium, iron, silicon can generate hard crisp β phase (Al
12Fe
3Si
2) be main form, the elongation of aluminium bar and tensile strength are reduced; Have only as w (Fe)/w (Si)>1 o'clock, aluminium, iron, silicon then generated α phase (Al
9Fe
2Si), though also be hard crisp phase, compare with β, its deformation nature is far better.So under the identical condition of the content of other impurity, control iron, silicone content and iron, silicon are the key problem in technology that improves electric conductivity and tensile strength during the aluminium bar is produced than w (Fe)/w (Si).
And produce the used homemade aluminium ingot of aluminium bar at present, and the trade mark needs more than Al99.70, and the content that requires aluminium is more than 99.70; The content of silicon is between 0.05%~0.10%, and the content of iron is between 0.08%~0.20%, and the content of general silicon is little; The content of iron is also little, thus adopt iron, aluminium ingot that silicone content is little, when resistivity reduces; Tensile strength also decreases, though control aluminium bar roll speed can improve the tensile strength of aluminium bar, the tensile strength of the aluminum steel of pulling out improves little.And adopting iron, aluminium ingot that silicone content is high, tensile strength can improve, but electric conductivity will descend.Current preparation aluminium bar generally be to choose the aluminium ingot of the trade mark more than A199.70 among standard GB/T 1196-2008, the content of silicon is no more than 0.10% in aluminium ingot, adopts to add the iron reinforcement and adjust iron, silicon ratio.We are after aluminium ingot fusing, and the content of its iron of on-the-spot sample analysis, silicon composition calculates the amount that should add the ferro-aluminum master alloy and adds in the stove, but this need stir it, otherwise will produce the inhomogeneous of aluminium bar tensile strength; But also to add ferro-aluminium, increased cost.
Summary of the invention
The present invention provides a kind of aluminium bar and preparation method thereof in order to overcome the deficiency of prior art, utilizes the tensile strength of the aluminium conductor that this aluminium bar processes high, and electric conductivity is high; The preparation technology of this aluminium bar is simple, cheap for manufacturing cost.
To achieve these goals, the present invention adopts following technical scheme: a kind of aluminium bar is characterized in that: its component and weight percent are:
Aluminium 99.70-99.74%;
Silicon 0.08-0.1%;
Iron 0.14-0.17%;
Impurity 0-0.5%;
Wherein, the ratio of iron silicon is 1.4 to 1.8.
As preferably, the weight percent of said silicon is 0.098%, and the weight percent of iron is 0.15%, and the tensile strength and the resistivity of the aluminium bar under this ratio are all more excellent.
As preferably, the weight percent of said silicon is 0.09%, and the weight percent of iron is 0.16%, and the tensile strength and the resistivity of the aluminium bar under this ratio are all more excellent.
The present invention also provides another technical scheme: a kind of preparation method of aluminium bar comprises the steps:
A, from the aluminium ingot of each batch, take a sample respectively, analyze the content of its aluminium, silicon, iron;
B, according to analytical results, choose standard compliant aluminium ingot: the content of aluminium is 99.70~99.74%, the content of silicon is 0.08~0.10%, the content of iron is between 0.14~0.17%, iron silicon ratio is between 1.4~1.8; If the proportioning of the aluminium of aluminium ingot, iron, silicone content is then selected aluminium, iron, the different batch aluminium ingot of silicone content, and calculated blend proportion, make the content and the iron silicon ratio conformance with standard of mixing back aluminium, iron, silicon not in above-mentioned standard;
C, with the melt in furnace of packing into of standard compliant aluminium ingot among the step b, temperature is controlled at 690~730 ℃; After the fusing, in holding furnace, be incubated, temperature of aluminum liquid is controlled at 700-720 ℃; When temperature of aluminum liquid reaches 720 ℃, add the agent of degasification deslagging refining, and stirred 3-5 minute, the weight of degasification deslagging refining agent is 0.5% of aluminium liquid gross weight; Refining is left standstill after 30-40 minute and is filtered after finishing, to remove impurity;
D, cast after filtering, cooling, tandem rolling, distaff lopping, during casting, pouring temperature is controlled at 680-700 ℃, casting rate is 0.19m/s; Temperature of cooling water is controlled at 15-20 ℃, and during tandem rolling, it is 450-500 ℃ that ingot blank advances to roll temperature, and the emulsion temperature remains on 20 ℃, and finishing temperature is 260-300 ℃, and it is 6.2m/s that finish to gauge goes out LV.
As preferably, in the above-mentioned steps, during said aluminium bar distaff, aluminium bar temperature is controlled at below 230 ℃.
As preferably, carry out refining among the said step c after, carry out secondary refining; With the slow aluminium liquid that evenly is blown into fusing of high purity nitrogen from all directions, make it fully to contact with aluminium liquid, remove the gas in the aluminium liquid; Time is 10-15 minute, and nitrogen pressure is controlled at below the 0.8Mpa.
We for improving aluminum steel electric conductivity and tensile strength, through test of many times, have confirmed aluminium, silicon, the content of iron and the optimum value of iron silicon ratio according to the mechanism that influences aluminum steel electric conductivity and tensile strength.Be controlled at the content of aluminium in the aluminium bar more than 99.70, the content of silicon is controlled at 0.08~0.10%, the content of iron 0.14~0.17%, iron silicon ratio is between 1.4~1.8; Adopt the resistivity and the tensile strength index of the aluminum steel of the aluminium bar production under this ratio to reach: the resistivity in the time of 20 ℃ is not more than 28.034n Ω m (national standard is 28.264n Ω m); Minimum tensile strength is not less than 176MPa (national standard is for being not less than 160MPa), and average tensile strength is greater than 181MPa.Compare aluminum steel of the prior art, electric conductivity and tensile strength are all very high.
Simultaneously; We have also invented the technology for preparing this kind aluminium bar: earlier each batch aluminium ingot is sampled, analyze the content of aluminium, silicon, iron in each batch aluminium ingot, carry out by weight ratio then; Make aluminium, silicon, iron and iron silicon ratio in the scope of regulation, carry out melting and rolling then.This preparation technology is simpler compared to traditional technology; The iron aluminium intermediate alloy need do not added; Both reduced production cost, but also guaranteed iron, silicon in the melting aluminum liquid evenly, avoided often occurring in the traditional technology the uneven phenomenon of aluminium bar tensile strength.Moreover; Can only be the aluminium ingot of the trade mark more than A199.70 in the prior art, as long as and this preparation technology has suitable trade mark aluminium ingot proportioning with it, the aluminium ingot of the trade mark below A199.70 also can use among standard GB/T 1196-2008; Choose raw-material, have the range of choice that more strengthens.
In the preparation process, temperature of aluminum liquid need be controlled at 690 ℃~730 ℃ during fusing, because the temperature of the breathing process of aluminium liquid and aluminium liquid is directly by relation, under this TR, the air-breathing degree of aluminium liquid is best, makes the quality of product reach optimum then.
When being incubated, when temperature in the stove reaches 720 ℃, drop into the degasification deslagging refining agent of oven dry, the agent of degasification deslagging refining is pressed into the total depths of aluminium liquid, moves horizontally, and after having reacted, stirs 3-5 minute, makes itself and the abundant contact reacts of aluminium liquid; The agent of degasification deslagging refining can be dissolved aluminum oxide and non-metallic inclusion, absorption and contraction, thereby changes the character of aluminium liquid surface film oxide, reaches the effect of slagging-off deflated.The degasification deslagging refining agent that the present invention uses is existing refining agent, and the refining agent staple is dystectic villaumite and villiaumite, after the adding, through physics and chemical action, from melt, removes metallic impurity, oxide compound and oxide impurity thereof.
After using degasification deslagging refining agent refining, if can't particularly in wet weather, also need carry out secondary refining the air scavenge in the aluminium liquid to the greatest extent; High purity nitrogen slowly is blown in the stove from all directions uniformly, usually adopts porous spherical nitrogen flushing pipe, be blown in the stove back and forth with " well " word trellis; Make it fully to contact with aluminium liquid, the time is 10-15 minute, and nitrogen pressure is controlled at below the 0.8Mpa; Make the little and disperse of bubble; Bubble had both been taken hydrogen out of in uphill process, also take residual inclusion out of, reached purified purpose again.
Refining is filtered after finishing, and to remove the oxide inclusion in the aluminium liquid, generally adopts glass yarn filtering net or honeycomb ceramic filter plate.
Cast after the filtration, during casting, pouring temperature is controlled at 680-700 ℃, and casting rate is 0.19m/s; The control of pouring temperature and casting rate, to crackle, the crack of ingot casting, defective decisive role such as shrinkage cavity, pouring temperature is too high, and the crystallizing wheel surface is prone to produce oxide film, and heat radiation is had violent influence, and ingot casting crackle waste product is increased; And temperature is crossed when low, will cause ingot casting surface cold shut to form, and loose, sull, slag inclusion waste product are increased.
After the casting, carry out water cooling, the temperature of water coolant is controlled at 15 ℃-20 ℃, and the temperature of water coolant can not be too high, can influence cooling intensity, and can form incrustation scale at the crystallizing wheel inner chamber, has a strong impact on ingot quality; Per hour 100 tons of cooling water inflows, internal cooling water ratio is 6:4, cooling water pressure 0.35MPa can guarantee that like this aluminium ingot base advances Zha Wendu between 450-500 ℃.
In the operation of rolling, roll speed, temperature, emulsion temperature and foreign matter content have very big influence to aluminium bar finished product, and roll speed is fast, and tensile strength is low, and unit elongation is high; Roll speed is slow, and tensile strength is high, and unit elongation is low, and general finish to gauge outlet speed control is at 6.2m/s, and finishing temperature is controlled at 260-300 ℃, and when satisfying the two condition, the aluminium bar tensile strength of producing is obviously higher.
For the homogeneity of the mechanical property that guarantees the aluminium bar, the aluminium bar after rolling is carried out water cooling and cooling is forced in air blast, aluminium bar temperature is controlled at below 230 ℃.
Through detecting; The tensile strength of aluminium bar exists: between the 118-121Mpa; Elongation is not less than 8%; Resistivity is not more than 27.85n Ω m, adopts the resistivity and the tensile strength index of the aluminum steel of this aluminium bar production to reach: the resistivity in the time of 20 ℃ is not more than 28.034n Ω m (national standard is 28.264n Ω m); Minimum tensile strength is not less than 176MPa (national standard is for being not less than 160MPa), and average tensile strength is greater than 181MPa.
Among the preparation method in the past; The content of silicon is greater than 0.16% in aluminium; Carry out the rare earth optimization process, normally in holding furnace, add the mishmetal RE of the 0.02-0.2% of aluminium liquid gross weight, with the deleterious effect of eliminating impurity element in the aluminium with play the effect of crystal grain thinning iso-metamorphism.When carrying out this step, be easy to the content of aluminium is taken away a part, influence performance of products.And among the preparation method of the present invention, the content that silicon can not occur has then saved this step greater than 0.16% situation, and convenient, the performance of the aluminium bar that makes is also better.
Among the preparation method in the past, when the total amount of the microelement Ti that influences electric conductivity in the aluminium, V, Cr, Mn greater than 0.01% the time, can add boronating agent by the aluminium liquid in holding furnace, boronating agent is with AL-B
3The master alloy form adds, and add-on commonly used is an aluminium 1-2 kilogram per ton, and the aluminium bar purity that preparation method of the present invention makes is high, and this step not was not only convenient but also practiced thrift cost.
In sum, the present invention has the following advantages:
1. the realization of aluminium bar of the present invention the effect of high-tensile, high conductivity, solved the shortcoming that existing aluminium bar tensile strength and electric conductivity can not satisfy simultaneously.
2. preparation technology of the present invention is simple, need not add master alloy, has practiced thrift cost greatly, has also guaranteed the homogeneity of aluminium bar tensile strength, can produce high conductivity, high-intensity aluminium bar.
Embodiment
In order to make those skilled in the art person better understand the present invention program; To combine the embodiment of the invention below, the technical scheme in the embodiment of the invention will be carried out clear, complete description, obviously; Described embodiment only is a part of embodiment of the present invention, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills are not making the every other embodiment that is obtained under the creative work prerequisite, all should belong to the scope of the present invention's protection.
Embodiment 1
My company has A to criticize aluminium ingot, and through analyzing, the content of its aluminium is 99.76%, and the content of iron is 0.13%, and the content of silicon is 0.07%, and according to general requirement, this aluminium ingot is reasonable.If but the aluminium bar of all producing with this aluminium ingot; Pull into the aluminum steel that diameter is 3.99mm; Though conductivity meets the requirements, tensile strength only between 165~178MPa, does not meet the requirement of user minimum tensile strength >=176MPa and average tensile strength >=181MPa.
B criticizes aluminium ingot, and through analyzing, the content of its aluminium is 99.67%; The content of iron is 0.18%, and the content of silicon is 0.11%, the aluminium bar of all producing with this aluminium ingot; Pull into the aluminum steel that diameter is 3.99mm, though tensile strength can reach 187~215MPa, conductivity only meets the requirements reluctantly; Resistivity is about 28.032n Ω m, and customer requirements is≤28.034n Ω m.
We these two batches of aluminium ingots by following proportioning: criticizing aluminium ingot weight with A is 1 part, and the B that joins 0.6 part of weight criticizes aluminium ingot, and with the aluminium ingot of the choosing melt in furnace of packing into, temperature is controlled at 690~730 ℃; After the fusing, in holding furnace, be incubated, temperature of aluminum liquid is controlled at 700-720 ℃; When temperature of aluminum liquid reaches 720 ℃, add the agent of degasification deslagging refining, and stirred 3-5 minute, the weight of degasification deslagging refining agent is 0.5% of aluminium liquid gross weight; Refining is left standstill after 30-40 minute and is filtered after finishing, to remove impurity; After carrying out refining, if can't need carry out secondary refining the air scavenge in the aluminium liquid to the greatest extent; High purity nitrogen slowly is blown in the stove with " well " trellis uniformly back and forth, and the time is 10-15 minute, and nitrogen pressure is controlled at below the 0.8Mpa; Preferably use porous spherical nitrogen flushing pipe, make the little and disperse of bubble, bubble had both been taken hydrogen out of in uphill process; Also take residual inclusion out of, reach purified purpose again.
Cast after the filtration, cooling, tandem rolling, distaff lopping, during casting, pouring temperature is controlled at 680 ℃, casting rate is 0.19m/s; Temperature of cooling water is controlled at 15 ℃, and during tandem rolling, it is 450 ℃ that ingot blank advances to roll temperature, and the emulsion temperature remains on 20 ℃, and finishing temperature is 260 ℃, and it is 6.2m/s that finish to gauge goes out LV, during the distaff of aluminium bar, aluminium bar temperature is controlled at 220 ℃.After the cooling, both got finished product.
Through detecting this batch aluminium bar:
The content of aluminium: 99.73%, the content of silicon: 0.085%, the content of iron: 0.149%, iron silicon ratio is: 1.75;
This batch aluminium bar pulls into the aluminum steel that diameter is 3.99mm:
Tensile strength can reach 180~197MPa, and resistivity≤27.998n Ω m satisfies user's requirement fully.
Embodiment 2
My company has C to criticize aluminium ingot, and through analyzing, the content of its aluminium is 99.79%; The content of iron is 0.12%; The content of silicon is 0.06%, pulls into the aluminum steel that diameter is 3.99mm, though conductivity meets the requirements; But tensile strength only between 159~169MPa, does not obviously meet the requirement of user minimum tensile strength >=176MPa and average tensile strength >=181MPa.
B criticizes aluminium ingot, and the content of its aluminium is 99.67%, and the content of iron is 0.18%; The content of silicon is 0.11%, and the aluminium bar of all producing with this aluminium ingot pulls into the aluminum steel that diameter is 3.99mm; Though tensile strength can reach 187~215MPa; But conductivity only meets the requirements reluctantly, and resistivity is about 28.032n Ω m, and customer requirements is≤28.034n Ω m.
We these two batches of aluminium ingots by following proportioning: criticizing aluminium ingot weight with C is 0.6 part, and the B that joins 1 part of weight criticizes aluminium ingot, and with the aluminium ingot of the choosing melt in furnace of packing into, temperature is controlled at 690~730 ℃; After the fusing, in holding furnace, be incubated, temperature of aluminum liquid is controlled at 700-720 ℃; When temperature of aluminum liquid reaches 720 ℃, add the agent of degasification deslagging refining, and stirred 3-5 minute, the weight of degasification deslagging refining agent is 0.5% of aluminium liquid gross weight; Refining is left standstill after 30-40 minute and is filtered after finishing, to remove impurity; After carrying out refining, if can't need carry out secondary refining the air scavenge in the aluminium liquid to the greatest extent; High purity nitrogen slowly is blown in the stove with " well " trellis uniformly back and forth, and the time is 10-15 minute, and nitrogen pressure is controlled at below the 0.8Mpa; Preferably use porous spherical nitrogen flushing pipe, make the little and disperse of bubble, bubble had both been taken hydrogen out of in uphill process; Also take residual inclusion out of, reach purified purpose again.
Cast after the filtration, cooling, tandem rolling, distaff lopping, during casting, pouring temperature is controlled at 700 ℃, casting rate is 0.19m/s; Temperature of cooling water is controlled at 24 ℃, and during tandem rolling, it is 470 ℃ that ingot blank advances to roll temperature, and the emulsion temperature remains on 20 ℃, and finishing temperature is 260 ℃, and it is 6.2m/s that finish to gauge goes out LV, during the distaff of aluminium bar, aluminium bar temperature is controlled at below 220 ℃.After the cooling, both got finished product.
Through detecting this batch aluminium bar:
The content of aluminium: 99.72%, the content of silicon: 0.09%, the content of iron: 0.16%, iron silicon ratio is: 1.78;
Use this batch aluminium bar to pull into the aluminum steel of diameter as 3.99mm:
Tensile strength can reach 182~199MPa, and resistivity≤27.599n Ω m satisfies user's requirement fully.
Embodiment 3
My company has D to criticize aluminium ingot, and through analyzing, the content of its aluminium is 99.65%; The content of iron is 0.19%, and the content of silicon is 0.12%, pulls into the aluminum steel that diameter is 3.99mm; Though tensile strength can reach 180~211MPa; But conductivity is undesirable, and resistivity is about 28.040n Ω m, and customer requirements is≤28.034n Ω m.
C criticizes aluminium ingot, and through analyzing, the content of its aluminium is 99.79%; The content of iron is 0.1%; The content of silicon is 0.07%, pulls into the aluminum steel that diameter is 3.99mm, though conductivity meets the requirements; But tensile strength only between 160~173MPa, does not obviously meet the requirement of user minimum tensile strength >=176MPa and average tensile strength >=181MPa.
We these two batches of aluminium ingots by following proportioning: criticizing aluminium ingot weight with D is 0.8 part, and the C that joins 1 part of weight criticizes aluminium ingot, and with the aluminium ingot of the choosing melt in furnace of packing into, temperature is controlled at about 730 ℃; After the fusing, in holding furnace, be incubated, temperature of aluminum liquid is controlled at 700-720 ℃; When temperature of aluminum liquid reaches 720 ℃, add the agent of degasification deslagging refining, and stirred 3-5 minute, the weight of degasification deslagging refining agent is 0.5% of aluminium liquid gross weight; Refining is left standstill after 30-40 minute and is filtered after finishing, to remove impurity; After carrying out refining, if can't need carry out secondary refining the air scavenge in the aluminium liquid to the greatest extent; High purity nitrogen slowly is blown in the stove with " well " trellis uniformly back and forth, and the time is 10-15 minute, and nitrogen pressure is controlled at below the 0.8Mpa; Preferably use porous spherical nitrogen flushing pipe, make the little and disperse of bubble, bubble had both been taken hydrogen out of in uphill process; Also take residual inclusion out of, reach purified purpose again.
Cast after the filtration, cooling, tandem rolling, distaff lopping, during casting, pouring temperature is controlled at 690 ℃, casting rate is 0.19m/s; Temperature of cooling water is controlled at 20 ℃, and during tandem rolling, it is 500 ℃ that ingot blank advances to roll temperature, and the emulsion temperature remains on 20 ℃, and finishing temperature is 260 ℃, and it is 6.2m/s that finish to gauge goes out LV, during the distaff of aluminium bar, aluminium bar temperature is controlled at below 220 ℃.After the cooling, both got finished product.
Through detecting this batch aluminium bar:
The content of aluminium: 99.71%, the content of silicon: 0.098%, the content of iron: 0.15%, iron silicon ratio is: 1.53;
Use this batch aluminium bar to pull into the aluminum steel of diameter as 3.99mm:
Tensile strength can reach 189~208MPa, and the average specific GB improves 20.3%, resistivity≤27.835n Ω m, and the average specific GB has reduced by 1.5%, satisfies user's requirement fully, and the each side of this batch aluminium bar is more excellent.
Embodiment 4
My company has D to criticize aluminium ingot, and through analyzing, the content of its aluminium is 99.65%; The content of iron is 0.19%, and the content of silicon is 0.12%, pulls into the aluminum steel that diameter is 3.99mm; Though tensile strength can reach 180~211MPa; But conductivity is undesirable, and resistivity is about 28.040n Ω m, and customer requirements is≤28.034n Ω m.
E criticizes aluminium ingot, and through analyzing, the content of its aluminium is 99.80%; The content of iron is 0.11%; The content of silicon is 0.04%, pulls into the aluminum steel that diameter is 3.99mm, though conductivity meets the requirements; But tensile strength only between 150~166MPa, does not obviously meet the requirement of user minimum tensile strength >=176MPa and average tensile strength >=181MPa.
We these two batches of aluminium ingots by following proportioning: criticizing aluminium ingot weight with E is 0.5 part, and the D that joins 1 part of weight criticizes aluminium ingot, and with the aluminium ingot of the choosing melt in furnace of packing into, temperature is controlled at about 720 ℃; After the fusing, in holding furnace, be incubated, temperature of aluminum liquid is controlled at 700-720 ℃; When temperature of aluminum liquid reaches 720 ℃, add the agent of degasification deslagging refining, and stirred 3-5 minute, the weight of degasification deslagging refining agent is 0.5% of aluminium liquid gross weight; Refining is left standstill after 30-40 minute and is filtered after finishing, to remove impurity; After carrying out refining, if can't need carry out secondary refining the air scavenge in the aluminium liquid to the greatest extent; High purity nitrogen slowly is blown in the stove with " well " trellis uniformly back and forth, and the time is 10-15 minute, and nitrogen pressure is controlled at below the 0.8Mpa; Preferably use porous spherical nitrogen flushing pipe, make the little and disperse of bubble, bubble had both been taken hydrogen out of in uphill process; Also take residual inclusion out of, reach purified purpose again.
Cast after the filtration, cooling, tandem rolling, distaff lopping, during casting, pouring temperature is controlled at 695 ℃, casting rate is 0.19m/s; Temperature of cooling water is controlled at 20 ℃, and during tandem rolling, it is 500 ℃ that ingot blank advances to roll temperature, and the emulsion temperature remains on 20 ℃, and finishing temperature is 260 ℃, and it is 6.2m/s that finish to gauge goes out LV, during the distaff of aluminium bar, aluminium bar temperature is controlled at below 220 ℃.After the cooling, both got finished product.
Through detecting this batch aluminium bar:
The content of aluminium: 99.70%, the content of silicon: 0.09%, the content of iron: 0.16%, iron silicon ratio is: 1.78;
Use the aluminium bar under this ratio to pull into the aluminum steel of diameter as 3.99mm:
Tensile strength can reach 180~191.78MPa, has improved 19.9% than GB, and resistivity≤27.76n Ω m has reduced by 1.8% than GB, and the each side index of this batch aluminium bar is more excellent.The foregoing description is the more excellent embodiment of part that we enumerate; The a lot of evidences of our processes: the content of aluminium is controlled at more than 99.70 in the aluminium bar; The content of silicon is controlled at 0.08~0.10%, the content of iron 0.14~0.17%, iron silicon ratio is between 1.4~1.8; Adopt the resistivity and the tensile strength index of the aluminum steel of the aluminium bar production under this ratio to reach: the resistivity in the time of 20 ℃ is not more than 28.034n Ω m, and national standard is 28.264n Ω m; Minimum tensile strength is not less than 176MPa, and national standard is for being not less than 160MPa, and average tensile strength is greater than 181MPa, and the complete National standard of each item index has very high practicality.