Highly corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment and method for manufacturing same

Abstract

The present invention relates to a highly corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment and a method for manufacturing same. The aluminum alloy composition comprises 0.0001-0.1500 parts by weight of silicon (Si), 0.0000-0.1000 parts by weight of copper (Cu), 0.9000-1.5000 parts by weight of manganese (Mn), 0.0000-0.3500 parts by weight of magnesium (Mg), 0.0500-0.4000 parts by weight of chromium (Cr), 0.0027-0.0500 parts by weight of zinc (Zn), 0.0500-0.4000 parts by weight of titanium (Ti), 0.0300-0.1500 parts by weight of zirconium (Zr), and 96.7500-98.8172 parts by weight of aluminum (Al) per 0.1835 parts by weight of iron (Fe).

Description

High-corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment and method for manufacturing the same

[0001] The present invention relates to a non-heat-treatable, high-strength, corrosion-resistant aluminum alloy composition and a method for producing the same, and more specifically, to a non-heat-treatable, high-strength, corrosion-resistant aluminum alloy composition having excellent strength and elongation and strong corrosion resistance, through establishing the content of chromium (Cr), titanium (Ti), and zirconium (Zr), the extrusion ratio during the manufacturing process, the extrusion speed, and the cross-sectional shrinkage rate, temperature, and time during drawing, and a method for producing the same.

[0002] Aluminum alloys are lightweight and strong, exhibit excellent electrical and thermal conductivity, and exhibit high heat and light reflectivity. Furthermore, they are highly corrosion-resistant, non-toxic, and castable, allowing them to be processed into any shape, making them an important industrial material.

[0003] These aluminum alloys are mainly used as materials for thin-walled precision pipes without heat treatment and for automotive parts that require strength, elongation, and corrosion resistance. In particular, precision pipe products are mainly used in aluminum alloys for automotive air conditioning, and are mainly manufactured as pipe materials for forming curved sections that are bent during bending. In order to include these curved sections, excessively high strength has a negative effect on the elongation characteristics that improve bendability, so the tensile strength should be 94~160N / mm. 2 , yield strength 50N / mm 2 It is appropriate to have the above values. In addition, the elongation must be more than 12% for banding properties.

[0004] However, existing aluminum alloy technology has the following problems.

[0005] Since it is difficult to improve both strength and elongation at the same time, there is a problem in that only one of the two characteristics, strength or elongation, is appropriately manufactured by controlling the material and content of the alloy.

[0006] In order to solve the above-mentioned problems, the purpose of the present invention is to invent a non-heat-treatable, high-strength, corrosion-resistant aluminum alloy composition having excellent strength and elongation and strong corrosion resistance by establishing the content of chromium (Cr), titanium (Ti), and zirconium (Zr), the extrusion ratio during the manufacturing process, the extrusion speed, and the cross-sectional shrinkage rate, temperature, and time during drawing, and a method for manufacturing the same.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a non-heat-treatable, high-strength aluminum alloy composition comprising: 0.1835 parts by weight of iron (Fe), 0.0001 to 0.1500 parts by weight of silicon (Si), 0.0000 to 0.1000 parts by weight of copper (Cu), 0.9000 to 1.5000 parts by weight of manganese (Mn), 0.0000 to 0.3500 parts by weight of magnesium (Mg), 0.0500 to 0.4000 parts by weight of chromium (Cr), 0.0027 to 0.0500 parts by weight of zinc (Zn), 0.0500 to 0.4000 parts by weight of titanium (Ti), 0.0300 to 0.1500 parts by weight of zirconium (Zr), and 0.0300 to 0.1500 parts by weight of aluminum (Al). It consists of 96.7500~98.8172 parts by weight.

[0008] The method for manufacturing the non-heat-treatable high-corrosion-resistant, high-strength aluminum alloy composition comprises the steps of: a first step of charging an aluminum (Al) ingot into a furnace and melting it; a second step of charging silicon (Si), iron (Fe), copper (Cu), manganese (Mn), magnesium (Mg), chromium (Cr), zinc (Zn), titanium (Ti), and zirconium (Zr) into the furnace in which the aluminum (Al) ingot is melted and melting it to manufacture an alloy; a third step of degassing the alloy; a fourth step of electromagnetically stirring the degassing alloy; a fifth step of tapping the electromagnetically stirred alloy from the furnace; a sixth step of casting the tapped alloy to manufacture a billet; a seventh step of homogenizing the billet; an eighth step of extruding the homogenized billet into a pipe; a ninth step of coiling the pipe; and a ninth step of forming the coiled pipe. It is characterized in that it is manufactured including a 10th step of drawing, an 11th step of straightening the drawn pipe, and a 12th step of cutting the straightened pipe.

[0009] The extrusion ratio in the extrusion of the above 8th step is, when manufacturing a pipe with a diameter of 8 pie, the billet cross-sectional area is 100 mm 2 When manufacturing pipes with a diameter of 12 pi, the billet cross-sectional area is 100 mm. 2 It is characterized by maintaining 99.5~311.

[0010] The cross-sectional shrinkage ratio during drawing in the above 10th step is characterized by being 5 to 10% when manufacturing a pipe with a diameter of 8 pi, and 1 to 3% when manufacturing a pipe with a diameter of 12 pi.

[0011] The melting of the first and second steps is characterized in that it proceeds at 660 to 800°C, the casting of the sixth step is characterized in that it proceeds when the alloy poured out of the fifth step is at 670 to 700°C, the homogenization treatment of the seventh step is characterized in that it proceeds at 590°C for 5 to 6 hours, and the extrusion of the eighth step is characterized in that it proceeds at a speed of 1 to 3 mm / s.

[0012] The non-heat-treatable, high-strength aluminum alloy composition and its manufacturing method according to the present invention have the following effects. By establishing the content of chromium (Cr), titanium (Ti), and zirconium (Zr), the extrusion ratio during the manufacturing process, the extrusion speed, and the cross-sectional shrinkage rate, temperature, and time during drawing, there is the advantage of excellent strength and elongation. In addition, in the case of a precision square that has not been drawn, there is the characteristic of having a strength similar to that of a drawn product even without drawing, and there is the advantage of strong corrosion resistance due to the alloy component containing corrosion-resistant characteristics.

[0013] Figure 1 is a process diagram of a method for manufacturing a high-corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment of an automobile component tube according to the present invention.

[0014] Figure 2 is a photograph before and after improvement of orange peel that occurred on the outer surface of a pipe manufactured according to the present invention.

[0015] Figure 3 is a photograph before and after improvement of scratches that occurred on the outer surface of a pipe manufactured according to the present invention.

[0016] Hereinafter, preferred embodiments of a high-corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment according to the present invention and a method for manufacturing the same will be described in detail with reference to the attached drawings.

[0017]

[0018] The present invention provides a non-heat-treatable, high-strength, high-corrosion-resistant aluminum alloy composition, characterized in that it comprises, with respect to 0.1835 parts by weight of iron (Fe), 0.0001 to 0.1500 parts by weight of silicon (Si), 0.0000 to 0.1000 parts by weight of copper (Cu), 0.9000 to 1.5000 parts by weight of manganese (Mn), 0.0000 to 0.3500 parts by weight of magnesium (Mg), 0.0500 to 0.4000 parts by weight of chromium (Cr), 0.0027 to 0.0500 parts by weight of zinc (Zn), 0.0500 to 0.4000 parts by weight of titanium (Ti), 0.0300 to 0.1500 parts by weight of zirconium (Zr), and 96.7500 to 98.8172 parts by weight of aluminum (Al). Do it.

[0019] The above silicon (Si) plays a role in improving fluidity in the alloy. Although it has low solubility strengthening in aluminum, it has the effect of precipitation strengthening by precipitation of magnesium silicide (Mg2Si) when coexisting with magnesium (Mg), so it is added in an amount of 0.0001 part by weight or more per 0.1835 part by weight of iron (Fe). However, silicon (Si) is a factor that slightly lowers toughness and somewhat promotes pitting formation, so if the content increases, corrosion resistance and surface condition may deteriorate. Therefore, it is preferable to maintain silicon (Si) at 0.1500 part by weight or less per 0.1835 part by weight of iron (Fe).

[0020] The iron (Fe) content above enables the casting to be demolded. However, if the iron (Fe) content is high, the intermetallic compound β-AlFeSi coarsely crystallizes, significantly reducing toughness. Therefore, it is desirable to maintain the iron (Fe) content below 0.1835 parts by weight, as this impairs corrosion resistance and reduces elongation and tensile strength.

[0021] The above copper (Cu) has a solid solution strengthening effect on aluminum and an extrusion strengthening effect through the intermediate phase of Al2Cu, thereby improving strength and machinability at both room temperature and high temperature. However, when it coexists with magnesium (Mg), a higher precipitation strengthening occurs due to the precipitation of the intermediate phase of Al2CuMg, which reduces extrudability, increases pipe strength, and reduces bendability. Therefore, it is preferable to maintain copper (Cu) at 0.100 parts by weight or less for 0.1835 parts by weight of iron (Fe).

[0022] Manganese (Mn) forms an Al(FeMn)Si compound, which prevents the weakening of toughness and corrosion resistance caused by iron (Fe) to some extent. Therefore, manganese (Mn) is added in an amount of 0.900 parts by weight or more per 0.1835 parts by weight of iron (Fe). However, manganese (Mn) can cause coarsening of the compound and become the cause of hot spots, so it is preferable to maintain manganese (Mn) at 1.500 parts by weight or less per 0.1835 parts by weight of iron (Fe).

[0023] Magnesium (Mg) exhibits significant precipitation strengthening when coexisting with zinc (Zn). However, magnesium (Mg) can form a primary magnesium silicide (Mg2Si) phase within the microstructure, which can deteriorate the properties of the alloy. Therefore, it is desirable to maintain the amount of Mg at 0.3500 parts by weight or less relative to 0.1835 parts by weight of iron (Fe).

[0024] Chromium (Cr) is added in an amount of 0.0500 parts by weight or more per 0.1835 parts by weight of iron (Fe) to control recrystallization, refine recrystallized grains, improve strength, and improve stress corrosion cracking. However, since chromium (Cr) can cause crystallized phases to remain within the material, which can lower the properties of the alloy, it is preferable to maintain it at 0.400 parts by weight or less per 0.1835 parts by weight of iron (Fe).

[0025] Zinc (Zn) exhibits remarkable precipitation strengthening when coexisting with magnesium (Mg), so it is added in an amount of 0.0027 parts by weight or more per 0.1835 parts by weight of iron (Fe). However, if there is a lot of zinc (Zn) during casting, the solidification shrinkage increases, which can easily cause casting defects, and the protective power of the aluminum (Al) oxide film can be weakened, which can worsen corrosion resistance, so it is preferable to maintain it at 0.0500 parts by weight or less per 0.1835 parts by weight of iron (Fe).

[0026] Titanium (Ti) is added in an amount of 0.0500 parts by weight or more per 0.1835 parts by weight of iron (Fe) to refine the grains by forming heterogeneous nuclei of primary aluminum (Al) phases such as TiAl3 and TiB2. However, iron (Fe) may remain as a crystallized phase within the material, which may deteriorate the properties of the alloy. Therefore, it is preferable to maintain an amount of 0.400 parts by weight or less per 0.1835 parts by weight of iron (Fe).

[0027] Zirconium (Zr) can prevent stress corrosion cracking, so it is added in an amount of 0.0300 parts by weight or more per 0.1835 parts by weight of iron (Fe). Within the range of 0.0300 to 0.1500 parts by weight of zirconium (Zr) per 0.1835 parts by weight of iron (Fe), corrosion resistance can be improved, and extrudability and bendability are within an acceptable range.

[0028]

[0029] The process of manufacturing a high-corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment according to the present invention using an aluminum alloy composition mixed in the composition ratio described above is described in detail below.

[0030]

[0031] First, the first step (S1) is performed by loading the aluminum (Al) ingot into the furnace and melting it. This is performed first because it contains the largest amount of aluminum (Al).

[0032]

[0033] Next, a second step (S2) is performed in which the molten aluminum (Al) ingot is charged with silicon (Si), iron (Fe), copper (Cu), manganese (Mn), magnesium (Mg), chromium (Cr), zinc (Zn), titanium (Ti), and zirconium (Zr) and melted to produce an alloy.

[0034] The melting of the first step (S1) and the second step (S2) is carried out at 660 to 800°C. If the melting is carried out below 660°C, the materials may not be sufficiently melted, making it impossible to manufacture a complete alloy. If the melting is carried out above 800°C, the hydrogen concentration in the molten metal rapidly increases due to the high temperature, resulting in a deterioration in the quality of the molten metal.

[0035]

[0036] Next, the third step (S3) of degassing the alloy is performed. This degassing process uses an inert gas such as Ar or N2 gas. This is done to ensure high quality.

[0037]

[0038] The fourth step (S4) of electronically stirring the above-degassed alloy is performed. This is a step to thoroughly mix the materials for the alloy.

[0039]

[0040] The fifth step (S5) of pouring the above-mentioned electronically stirred alloy from the furnace is performed. This is to perform casting by solidifying the well-mixed alloy within a continuous casting mold.

[0041]

[0042] A sixth step (S6) is performed to manufacture a billet by casting the above-mentioned molten alloy.

[0043] The above casting is performed when the molten alloy of the above fifth step (S5) is at a temperature of 670 to 700°C. This is because if the molten alloy is below 670°C, it may harden during casting, making the casting process difficult. If the molten alloy exceeds 700°C, casting defects such as cracks due to temperature deviation may occur.

[0044]

[0045] Next, the seventh step (S7) of homogenizing the billet is performed. Homogenization refers to uniformizing the metal structure, and involves heat treating the material at a high temperature to reduce or eliminate chemical segregation through diffusion.

[0046] The above homogenization treatment is carried out at 590°C for 5 to 6 hours. If the homogenization is carried out at a temperature lower than 590°C, the chemical segregation may not be reduced or eliminated due to low temperature, and if the homogenization is carried out at a temperature higher than 590°C, the strength may be reduced due to intragranular destruction, intergranular destruction, etc. of the billet due to high temperature. Similarly, if the homogenization is carried out for less than 5 hours, the chemical segregation may not be reduced or eliminated due to short time.

[0047] And, if the homogenization proceeds for more than 6 hours, the strength may decrease due to intragranular destruction or intergranular destruction of the billet due to the long time.

[0048]

[0049] Next, the 8th step (S8) of extruding the homogenized billet into a pipe is performed.

[0050] In the case of precision tube process used in automobiles, the extrusion cost is when manufacturing a pipe with a diameter of 8 pi, and the billet cross-sectional area is 100 mm. 2 When manufacturing pipes with a diameter of 12 pi, the billet cross-sectional area is 100 mm. 2It should be maintained at 99.5~311. If it exceeds this, a lot of work hardening occurs, so the tensile strength and yield strength increase, but the elongation decreases, making it difficult to manufacture into pipes. In addition, if it is lower than this, work hardening decreases, so the elongation increases, but the tensile strength and yield strength decrease, which may cause defects, corrosion, or destruction.

[0051] Additionally, the extrusion speed is maintained at 1-3 mm / s. If the extrusion speed is less than 1 mm / s, production volume may decrease, and if the extrusion speed exceeds 3 mm / s, the surface temperature may rise rapidly, resulting in surface cracks and bursting.

[0052]

[0053] Next, a ninth step (S9) of winding the pipe is performed. The winding is performed to facilitate storage and transportation.

[0054]

[0055] Next, a 10th step (S10) of drawing the above-mentioned coiled pipe is performed.

[0056] The cross-sectional reduction ratio during the drawing should be maintained at 5-10% when manufacturing a pipe with a diameter of 8 pi, and 1-3% when manufacturing a pipe with a diameter of 12 pi. If the cross-sectional reduction ratio is lower than this, work hardening is reduced, so the elongation increases, but the tensile strength and yield strength decrease, and the production rate also decreases. In addition, if the cross-sectional reduction ratio is higher than this, work hardening occurs significantly, so the tensile strength and yield strength increase, but the elongation decreases, making it difficult to manufacture into pipes.

[0057]

[0058] Next, step 11 (S11) of correcting the above-mentioned drawn pipe is performed.

[0059] Next, step 12 (S12) is performed to cut the above-mentioned corrected pipe. This is to cut it into an appropriate size for commercialization.

[0060]

[0061] Next, various characteristics of a high-corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment, which is a field of the present invention, for precision tubes for automobile parts, were examined.

[0062]

[0063] First, the alloy compositions of Examples 1, 2, 3, and 4 manufactured using the high-corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment according to the present invention, Examples 5, 6, and 7 manufactured using an alloy having a composition outside the composition range of the high-corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment according to the present invention, and a conventional example, which is a commercially used A3003 series pipe, were compared in Table 1.

[0064] An alloy having the composition shown in Table 1 was melted at 660°C to produce an alloy, which was then degassed, stirred electronically, and tapped, and cast at 670°C to produce a billet. The billet was then homogenized at 590°C for 5 hours, and then extruded, coiled, drawn, straightened, and cut to produce a pipe.

[0065]

[0066] Weight part reference SiFeCuMnMgCrZnTiZrAl 10.114 20.183 50.063 41.2112-0.25 100.01 180.2069-97.95 80 Example 20.119 80.183 50.063 81.287 20.326 00.294 90.01 300.2167-97.495 130.01 200.1835-1.1794-0.1174 0.003 40.1215-98.38 284 0.025 70.1835-0.9164-0.097 20.0027 0.092 50.033298.648850.02570.1835-0.9164-0.05000.00270.09250.033298.696060.02570.1835-0.9164-0.09720.00270.05000.033298.696070.02570.1835-0.9164-0.09720.00270.09250.150098.532010.13500.37200.14001.13900.00800.00700.00600.0070-traditional example

[0067] Tensile strength (N / mm) 2 ) Yield strength (N / mm) 2 ) Elongation (%) Example 1 1448040 Example 2 1607832 Example 3 1218335 Example 4 988642 Example 5 928031 Example 6 907630 Example 7 1009020 Conventional Example 1 1096241

[0068] For aluminum alloys used as automobile air conditioning pipes, tensile strength of 94 to 160 N / mm 2 , yield strength 50N / mm 2 Above, the elongation must be satisfied at least 12%. Referring to Table 2, all examples except for Examples 5 and 6 satisfy the specifications of aluminum alloys for use as automobile air conditioning pipes. However, in the case of Example 7, although the values ​​of tensile strength and yield strength of the aluminum alloy for use as automobile air conditioning pipes are satisfied, the elongation is significantly lower than that of the other examples, so it can be determined that it is not suitable for use.

[0069] Looking at Examples 5, 6, and 7 in detail, in the case of Example 5, it can be seen through the alloy composition in Table 1 that the chromium (Cr) content is reduced compared to Example 4, and it can be seen through Table 2 that the strength is lowered. This can be seen as a result of the strength improvement due to the control of recrystallization by chromium (Cr) and refinement of recrystallized grains not being sufficiently achieved. Therefore, it can be seen that adding 0.0500 parts by weight or less of chromium (Cr) to 0.1835 parts by weight of iron (Fe) is meaningless.

[0070] In the case of Example 6, it can be seen through the alloy composition in Table 1 that the content of titanium (Ti) is reduced compared to Example 4, and it can be seen through Table 2 that the strength is lowered. This is because titanium (Ti) aluminum (aluminum (Al)3 and titanium (Ti) B2) by titanium (Ti) do not have sufficient heterogeneous nuclei of primary aluminum (aluminum (Al) phase, so grain refinement is not achieved. Therefore, it can be seen that adding 0.0500 parts by weight or less of titanium (Ti) to 0.1835 parts by weight of iron (Fe) is meaningless.

[0071] In the case of Example 7, it can be seen from the alloy composition in Table 1 that the zirconium (Zr) content has increased compared to Example 4, and the zirconium (Zr) elongation can be seen from Table 2. This is the result of the high zirconium (Zr) content, which has resulted in decreased extrudability and elongation. Therefore, it can be seen that it is meaningless to exceed 0.1500 parts by weight of zirconium (Zr) for 0.1835 parts by weight of iron (Fe).

[0072] Therefore, it is preferable to manufacture a pipe with the alloy composition of Example 1, Example 2, Example 3, Example 4 and the conventional example.

[0073] However, referring to Table 2, it can be confirmed that although the elongation values ​​of Examples 1, 2, 3, and 4 and the conventional example are similar, the yield strengths of Examples 1, 2, 3, and 4 are higher than those of the conventional example. In addition, it can be confirmed that Examples 1, 2, and 3 have higher tensile strengths than those of the conventional example 1. This means that the alloy compositions of the examples withstand external forces better than those of the conventional example, and therefore, it can be seen that manufacturing a pipe with the alloy compositions of Examples 1, 2, 3, and 4 is more preferable than that of the conventional example.

[0074]

[0075] Next, the experimental results of the method for manufacturing a high-corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment according to the present invention will be described in detail.

[0076]

[0077] (a) Results analysis

[0078] The presence of orange peel and scratches on the outer surface of the pipe manufactured according to the difference in the manufacturing process of the aluminum alloy of the present invention was determined. If 5 or more orange peels were found on the surface, it was marked as ×, if 3 or more were found, it was marked as △, and if none were found, it was marked as ○. If many scratches were found on the surface, it was marked as ×, if they were good, it was marked as △, and if none were found, it was marked as ○. The orange peel refers to the surface being not smooth and becoming like the peel of a tangerine.

[0079]

[0080] (1) Analysis of the results of 8-pi diameter pipes manufactured from aluminum alloy for automobile air conditioning according to extrusion ratio.

[0081]

[0082] Examples 8, 9, and 10 produced alloys with the composition of Example 1. The production method is as follows.

[0083] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), copper (Cu), chromium (Cr), zinc (Zn), and titanium (Ti) were placed in the furnace and melted at 660°C to produce an alloy. After degassing, electromagnetic stirring, and tapping of the alloy, it was cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, and Example 8 was a billet with a cross-sectional area of ​​100 mm. 2 For the extrusion ratio of 829, Example 9 is a billet cross-sectional area of ​​100 mm 2 For the extrusion ratio of 576, Example 10 is a billet cross-sectional area of ​​100 mm 2 After extrusion at an extrusion ratio of 368, a pipe with a diameter of 8 pi was manufactured by winding, drawing, straightening, and cutting.

[0084]

[0085] Examples 11, 12, and 13 produced alloys with the composition of Example 2. The production method is as follows.

[0086] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), copper (Cu), magnesium (Mg), chromium (Cr), zinc (Zn), and titanium (Ti) were placed in the furnace and melted at 660°C to produce an alloy. After degassing, electromagnetic stirring, and tapping of the alloy, it was cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, and Example 11 was a billet with a cross-sectional area of ​​100 mm. 2 For the extrusion ratio of 829, Example 12 is a billet cross-sectional area of ​​100 mm 2 For the extrusion ratio of 576, Example 13 is a billet cross-sectional area of ​​100 mm 2 After extrusion at an extrusion ratio of 368, a pipe with a diameter of 8 pi was manufactured by winding, drawing, straightening, and cutting.

[0087]

[0088] Examples 14, 15, and 16 produced alloys with the composition of Example 3. The production method is as follows.

[0089] Aluminum (Al) ingot was first put into the furnace, and then silicon (Si), iron (Fe), manganese (Mn), aluminum (Al), zinc (Zn), and titanium (Ti) ingots were put into the master alloy and melted at 660°C to produce an alloy. After degassing, electromagnetic stirring, and tapping of the alloy, it was cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, and Example 14 had a billet cross-sectional area of ​​100 mm. 2 For the extrusion ratio of 829, Example 15 is a billet cross-sectional area of ​​100 mm 2 For the extrusion ratio of 576, Example 16 is a billet cross-sectional area of ​​100 mm 2 After extrusion at an extrusion ratio of 368, a pipe with a diameter of 8 pi was manufactured by winding, drawing, straightening, and cutting.

[0090]

[0091] Examples 17 and 18 produced alloys with the composition of Example 4. The production method is as follows.

[0092] Aluminum (Al) ingot was first put into the furnace, and then silicon (Si), iron (Fe), manganese (Mn), aluminum (Al), zinc (Zn), titanium (Ti), and zirconium (Zr) were put into the furnace and melted at 660°C to produce an alloy. After degassing treatment of zirconium (Zr), electronic stirring, and tapping, the billet was cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours. Example 17 is a billet with a cross-sectional area of ​​100 mm. 2 For the extrusion ratio of 368, Example 18 is a billet cross-sectional area of ​​100 mm 2 After extrusion at an extrusion ratio of 184, a pipe with a diameter of 8 pi was manufactured by winding, drawing, straightening, and cutting.

[0093]

[0094] Weight part Extrusion ratio SiFeCuMnMgCrZnTiZrAl Example 80.11420.18350.06341.2112-0.25100.01180.2069-97.9580829 Alloy of Example 1 Example 90.11420.18350.06341.2112-0.25100.01180.2069-97.9580576 Example 100.11420.18350.06341.2112-0.25100.01180.2069-97.9580368 Example 110.11980.18350.06381.28720.32600.29490.01300.2167-97.4951829 Alloy of Example 2 Example 120.11980.18350.06381.28720.32600.29490.01300.2167-97.4951576 Example 130.11980.18350.06381.28720.32600.29490.01300.2167-97.4951368 Example 140.01200.1835-1.1794-0.11740.00340.1215-98.3828829 Alloy of Example 3 Example 150.01200.1835-1.1794-0.11740.00340.1215-98.3828576 Alloy of Example 160.01200.1835-1.1794-0.11740.00340.1215-98.3828368 Alloy of Example 170.02570.1835-0.9164-0.09720.00270.09250.033298.6488368 Alloy of Example 4 Example 180.02570.1835-0.9164-0.09720.00270.09250.033298.6488184

[0095] Orange Peel Scratch Example 8×× Example 9△△ Example 10○△ Example 11×× Example 12△△ Example 13○△ Example 14△△ Example 15○△ Example 16○○ Example 17○○ Example 18○○

[0096] As shown in Tables 3 and 4, it can be seen that the pipe manufacturing process using the alloy compositions of Examples 3 and 4 produced better results than the alloy compositions of Examples 1 and 2. The fact that many orange peels and scratches appeared in Examples 8, 9, 10, 11, 12, and 13 manufactured using the alloy compositions of Examples 1 and 2 can be largely attributed to the fact that zirconium (Zr) was not included in the alloy components. Zirconium (Zr) is a factor that improves corrosion resistance and can resolve stress corrosion cracking. In addition, although the alloy component of Example 3 does not contain zirconium (Zr), the reason why less orange peel and scratches occurred than in Examples 1 and 2 is because the content of chromium (Cr) and titanium (Ti) was lowered. By lowering the chromium (Cr) and titanium (Ti) content, no crystallites are formed inside, which may have resulted in less orange peel and scratches.

[0097] In addition, through Table 4, it can be confirmed that although the alloy has the same composition, examples 15 and 16 did not have orange peel and had no or good scratches, while example 14 had more than 3 orange peels and good scratches. This means that the extrusion ratio is high. It can be seen that the elongation is reduced, the surface temperature is increased, and surface cracks are generated due to the high extrusion ratio. Therefore, when the cross-sectional area of ​​the billet is 100 mm 2 The extrusion ratio of 829 can be considered meaningless.

[0098] In addition, it was found that the extrusion ratio was in good condition up to 184 through Example 18 of Table 4. However, since an extrusion ratio of a lower value than this decreases the strength and the production volume per hour, the value of Example 18, which is a cross-sectional area of ​​the billet of 100 mm, 2 It is desirable to specify 184 as the minimum extrusion ratio.

[0099]

[0100] (2) Analysis of the results of a 12-pi diameter pipe manufactured from aluminum alloy according to the extrusion ratio.

[0101]

[0102] Examples 19, 20, and 21 produced alloys with the composition of Example 1. The production method is as follows.

[0103] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), copper (Cu), manganese (Mn), chromium (Cr), zinc (Zn), and titanium (Ti) were placed in the furnace and melted at 660°C to produce an alloy. After degassing, electromagnetic stirring, and tapping of the alloy, it was cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours. Example 19: A billet having a cross-sectional area of ​​100 mm 2 For the extrusion ratio of 448, Example 20 is a billet cross-sectional area of ​​100 mm 2 For the extrusion ratio of 311, Example 21 is a billet cross-sectional area of ​​100 mm 2 After extruding with 199 extrusion B, a pipe with a diameter of 12 pi was manufactured by winding, drawing, straightening, and cutting.

[0104]

[0105] Examples 22, 23, and 24 produced alloys with the composition of Example 2. The production method is as follows.

[0106] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), copper (Cu), manganese (Mn), magnesium (Mg), chromium (Cr), zinc (Zn), and titanium (Ti) were placed in the furnace and melted at 660°C to produce an alloy. After degassing, electromagnetic stirring, and tapping of the alloy, it was cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, and Example 22 had a billet cross-sectional area of ​​100 mm. 2 For the extrusion ratio of 448, Example 23 is a billet cross-sectional area of ​​100 mm2 For the extrusion ratio of 311, Example 24 is a billet cross-sectional area of ​​100 mm 2 After extrusion at an extrusion ratio of 199, a pipe with a diameter of 12 pi was manufactured by winding, drawing, straightening, and cutting.

[0107]

[0108] Examples 25, 26, and 27 produced alloys with the composition of Example 3. The production method is as follows.

[0109] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), manganese (Mn), chromium (Cr), zinc (Zn), and titanium (Ti) ingots were placed in the master alloy, melted at 660°C to produce an alloy, and the alloy was degassed, stirred electronically, and tapped, and then cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, and Example 25 had a billet cross-sectional area of ​​100 mm. 2 For the extrusion ratio of 448, Example 26 is a billet cross-sectional area of ​​100 mm 2 For the extrusion ratio of 311, Example 27 is a billet cross-sectional area of ​​100 mm 2 After extrusion at an extrusion ratio of 199, a pipe with a diameter of 12 pi was manufactured by winding, drawing, straightening, and cutting.

[0110]

[0111] Examples 28 and 29 produced alloys with the composition of Example 4. The production method is as follows.

[0112] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), manganese (Mn), chromium (Cr), zinc (Zn), titanium (Ti), and zirconium (Zr) were placed in the furnace and melted at 660°C to produce an alloy. After degassing, electromagnetic stirring, and tapping of the alloy, it was cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, and Example 28 was a billet with a cross-sectional area of ​​100 mm. 2 For an extrusion ratio of 199, Example 29 is a billet with a cross-sectional area of ​​100 mm 2 After extrusion at an extrusion ratio of 99.5, a pipe with a diameter of 12 pi was manufactured by winding, drawing, straightening, and cutting.

[0113]

[0114] Weight part Extrusion ratio Remarks SiFeCuMnMgCrZnTiZrAl Example 190.11420.18350.06341.2112-0.25100.01180.2069-97.9580448 Alloy of Example 1 Example 200.11420.18350.06341.2112-0.25100.01180.2069-97.9580311 Example 210.11420.18350.06341.2112-0.25100.01180.2069-97.9580199 Example 220.11980.18350.06381.28720.32600.29490.01300.2167-97.4951448 Alloy of Example 2 Example 230.11980.18350.06381.28720.32600.29490.01300.2167-97.4951311 Example 240.11980.18350.06381.28720.32600.29490.01300.2167-97.4951199 Example 250.01200.1835-1.1794-0.11740.00340.1215-98.3828448 Alloy of Example 3 Example 260.01200.1835-1.1794-0.11740.00340.1215-98.3828311 Alloy of Example 270.01200.1835-1.1794-0.11740.00340.1215-98.3828199 Alloy of Example 280.02570.1835-0.9164-0.09720.00270.09250.033298.6488199 Alloy of Example 4 Example 290.02570.1835-0.9164-0.09720.00270.09250.033298.648899.5

[0115] Orange Peel Scratch Example 19×× Example 20△× Example 21○△ Example 22×× Example 23△× Example 24○△ Example 25△△ Example 26○△ Example 27○○ Example 28○○ Example 29○○

[0116] As shown in Tables 5 and 6, it can be seen that the pipe manufacturing process using the alloy compositions of Examples 3 and 4 produced better results than the alloy compositions of Examples 1 and 2. The fact that many orange peels and scratches appeared in Examples 19, 20, 21, 22, 23, and 24 manufactured using the alloy compositions of Examples 1 and 2 can be largely attributed to the fact that zirconium (Zr) was not included in the alloy components. Zirconium (Zr) is a factor that improves corrosion resistance and can resolve stress corrosion cracking. In addition, although the alloy component of Example 3 does not contain zirconium (Zr), the reason why less orange peel and scratches occurred than in Examples 1 and 2 is because the content of chromium (Cr) and titanium (Ti) was lowered. By lowering the chromium (Cr) and titanium (Ti) content, no crystallites are formed inside, which may have resulted in less orange peel and scratches.

[0117] In addition, through Table 6, it can be confirmed that although the alloy has the same composition, examples 26 and 27 did not develop orange peel and had no or good scratches, while example 25 had three or more orange peels and good scratches. This means that the extrusion ratio is high. It can be seen that the elongation is reduced, the surface temperature rises, and surface cracks occur due to the high extrusion ratio. Therefore, when the cross-sectional area of ​​the billet is 100 mm 2 The extrusion ratio of 448 can be considered meaningless.

[0118] In addition, it was found that the extrusion ratio was in good condition up to 99.5 through Example 29 of Table 6. However, since an extrusion ratio of a lower value than this decreases strength and production volume per hour, the value of Example 29, which is a billet cross-sectional area of ​​100 mm, 2 It is desirable to specify 99.5 as the minimum extrusion ratio.

[0119]

[0120] (3) Analysis of the results of a pipe with a diameter of 8 pi manufactured from aluminum alloy according to the cross-sectional shrinkage rate during drawing.

[0121]

[0122] Examples 30, 31, 32, and 33 produced alloys with the composition of Example 1. The production method is as follows.

[0123] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), copper (Cu), manganese (Mn), chromium (Cr), zinc (Zn), and titanium (Ti) were placed in the furnace and melted at 660°C to produce an alloy. After degassing treatment, electromagnetic stirring, and tapping of the alloy, it was cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, extruded at an extrusion ratio of 368, and wound. Then, Example 30 had a cross-sectional shrinkage of 2%, Example 31 had a cross-sectional shrinkage of 5%, Example 32 had a cross-sectional shrinkage of 7%, and Example 33 had a cross-sectional shrinkage of 10%, and was then drawn and cut to produce a pipe with a diameter of 8 pi.

[0124]

[0125] Examples 34, 35, 36, and 37 produced alloys with the composition of Example 2. The production method is as follows.

[0126] Aluminum (Al) ingot was first put into the furnace, and then silicon (Si), iron (Fe), copper (Cu), manganese (Mn), magnesium (Mg), chromium (Cr), zinc (Zn), and titanium (Ti) were put into the furnace and melted at 660°C to produce an alloy, and the alloy was degassed, stirred electronically, and tapped, and then cast at 670°C to produce a billet. Thereafter, the billet was homogenized at 590°C for 5 hours, extruded at an extrusion ratio of 368, and wound. Then, Example 34 had a cross-sectional shrinkage of 2%, Example 35 had a cross-sectional shrinkage of 5%, Example 36 had a cross-sectional shrinkage of 7%, and Example 37 had a cross-sectional shrinkage of 10%, and was then drawn and cut to produce a pipe with a diameter of 8 pi.

[0127]

[0128] Examples 38, 39, 40, and 41 produced alloys with the composition of Example 3. The production method is as follows.

[0129]

[0130] *Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), manganese (Mn), chromium (Cr), zinc (Zn), and titanium (Ti) ingots were placed in the master alloy, melted at 660°C to produce an alloy, and the alloy was degassed, stirred electronically, and tapped, and then cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, extruded at an extrusion ratio of 368, and wound. Then, Example 38 had a cross-sectional shrinkage of 2%, Example 39 had a cross-sectional shrinkage of 5%, Example 40 had a cross-sectional shrinkage of 7%, and Example 41 had a cross-sectional shrinkage of 10%, and was then drawn and cut to produce a pipe with a diameter of 8 pi.

[0131]

[0132] Examples 42, 43, 44, and 45 produced alloys with the composition of Example 4. The production method is as follows.

[0133] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), manganese (Mn), chromium (Cr), zinc (Zn), titanium (Ti), and zirconium (Zr) were placed in the furnace and melted at 660°C to produce an alloy. The alloy was degassed, stirred electronically, and tapped, and then cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, extruded at an extrusion ratio of 368, and wound. Then, Example 42 had a cross-sectional shrinkage of 2%, Example 43 had a cross-sectional shrinkage of 5%, Example 44 had a cross-sectional shrinkage of 7%, and Example 45 had a cross-sectional shrinkage of 10%, and was then drawn and cut to produce a pipe with a diameter of 8 pi.

[0134]

[0135] Weight Drawing Section Shrinkage (%) Remarks SiFeCuMnMgCrZnTiZrAl Example 30 0.1142 0.1835 0.0634 1.2112-0.25 100.0118 0.2069-97.95802 Alloy of Example 1 Example 310.1142 0.1835 0.0634 1.2112-0.25 100.0118 0.2069-97.95805 Example 320.1142 0.1835 0.0634 1.2112-0.25 100.0118 0.2069-97.95807 Example 330.11400.18350.06341.2112-0.25100.01180.2069-97.958010 Example 340.11980.18350.06381.28720.32600.29490.01300.2167-97.49512 Alloy of Example 2 Example 350.11980.18350.06381.28720.32600.29490.01300.2167-97.49515 Example 360.11980.18350.06381.28720.32600.29490.01300.2167-97.49517 Example 370.11980.18350.06381.28720.32600.29490.01300.2167-97.495110 Example 380.01200.1835-1.1794-0.11740.00340.1215-98.38282 Alloy of Example 3 Example 390.01200.1835-1.1794-0.11740.00340.1215-98.38285 Example 400.01200.1835-1.1794-0.11740.00340.1215-98.38287 Example 410.01200.1835-1.1794-0.11740.00340.1215-98.382810 Example 420.02570.1835-0.9164-0.09720.00270.09250.033298.64882 Alloy of Example 4 Example 430.02570.1835-0.9164-0.09720.00270.09250.033298.64885 Example 440.02570.1835-0.9164-0.09720.00270.09250.033298.64887 Example 450.02570.1835-0.9164-0.09720.00270.09250.033298.648810

[0136] Orange Peel Scratch Example 30×× Example 31○△ Example 32○△ Example 33○× Example 34×× Example 35○△ Example 36○△ Example 37○× Example 38△× Example 39○○ Example 40○○ Example 41○△ Example 42△× Example 43○○ Example 44○○ Example 45○△

[0137] As shown in Tables 7 and 8, it can be seen that the pipe manufacturing process using the alloy compositions of Examples 3 and 4 produced better results than the alloy compositions of Examples 1 and 2. The fact that many orange peels and scratches appeared in Examples 30, 31, 32, 33, 34, 35, 36, and 37 manufactured using the alloy compositions of Examples 1 and 2 can be largely attributed to the fact that zirconium (Zr) was not included in the alloy components. Zirconium (Zr) is a factor that improves corrosion resistance and can resolve stress corrosion cracking. In addition, although the alloy component of Example 3 does not contain zirconium (Zr), the reason why less orange peel and scratches occurred than in Examples 1 and 2 is because the content of chromium (Cr) and titanium (Ti) was lowered. By lowering the chromium (Cr) and titanium (Ti) content, no crystallites are formed inside, which may have resulted in less orange peel and scratches.

[0138] In addition, through Table 8, it can be confirmed that the pipes of Examples 31 and 32 are in better condition than those of Examples 30 and 33, even though they are alloys of the same composition. In addition, the pipes of Examples 35 and 36 are in better condition than those of Examples 34 and 37, and the pipes of Examples 39 and 40 are in better condition than those of Examples 38 and 41. Similarly, it can be confirmed that the pipes of Examples 43 and 44 are in better condition than those of Examples 42 and 45.

[0139] This is believed to be due to the difference in cross-sectional shrinkage. If the cross-sectional shrinkage is low, the strength decreases and cannot withstand external forces, and orange peel or scratches may occur. Therefore, both orange peel and scratches may have occurred in Examples 30, 34, 38, and 42, which have a cross-sectional shrinkage of 2%. In addition, since the elongation decreases when the cross-sectional shrinkage is high, orange peel and scratches may occur more. Therefore, scratches may have occurred in Examples 33, 37, 41, and 45, which have a cross-sectional shrinkage of 10%. However, since this is a good scratch, it is desirable to specify the cross-sectional shrinkage at 5 to 10% when drawing a pipe with a diameter of 8 pi.

[0140]

[0141] (4) Analysis of the results of a 12-pi diameter pipe manufactured from aluminum alloy according to the cross-sectional shrinkage rate during drawing.

[0142]

[0143] Examples 46, 47, and 48 produced alloys with the composition of Example 1. The production method is as follows.

[0144] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), copper (Cu), manganese (Mn), chromium (Cr), zinc (Zn), and titanium (Ti) were placed in the furnace and melted at 660°C to produce an alloy. The alloy was degassed, stirred electronically, and tapped, and then cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, and then extruded and coiled. Example 46 had a cross-sectional shrinkage of 1%, Example 47 had a cross-sectional shrinkage of 3%, and Example 48 had a cross-sectional shrinkage of 5%, and then drawn and cut to produce a pipe with a diameter of 12 pi.

[0145]

[0146] Examples 49, 50, and 51 produced alloys with the composition of Example 2. The production method is as follows.

[0147] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), copper (Cu), manganese (Mn), magnesium (Mg), chromium (Cr), zinc (Zn), and titanium (Ti) were placed in the furnace and melted at 660°C to produce an alloy. The alloy was degassed, stirred electronically, and tapped, and then cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, extruded, coiled, and then drawn and cut to produce a pipe with a diameter of 12 pi at a cross-sectional shrinkage of 1% in Example 49, 3% in Example 50, and 5% in Example 51.

[0148]

[0149] Examples 52, 53, and 54 produced alloys with the composition of Example 3. The production method is as follows.

[0150] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), manganese (Mn), chromium (Cr), zinc (Zn), and titanium (Ti) ingots were placed in the master alloy and melted at 660°C to produce an alloy. The alloy was degassed, stirred electronically, and tapped, and then cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, extruded, coiled, and then drawn and cut to produce a pipe with a diameter of 12 pi with a cross-sectional shrinkage of 1% in Example 52, 3% in Example 53, and 5% in Example 54.

[0151]

[0152] Examples 55, 56, and 57 produced alloys with the composition of Example 4. The production method is as follows.

[0153] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), manganese (Mn), chromium (Cr), zinc (Zn), titanium (Ti), and zirconium (Zr) were placed in the furnace and melted at 660°C to produce an alloy. The alloy was degassed, stirred electronically, and tapped, and then cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, extruded, and coiled, and then drawn and cut to produce a pipe with a diameter of 12 pi at a cross-sectional shrinkage of 1% in Example 55, 3% in Example 56, and 5% in Example 57.

[0154]

[0155] Weight Drawn Section Shrinkage (%) Remarks SiFeCuMnMgCrZnTiZrAl Example 46 0.1142 0.1835 0.0634 1.2112-0.25 100.0118 0.2069-97.95801 Alloy of Example 1 Example 47 0.1142 0.1835 0.0634 1.2112-0.25 100.0118 0.2069-97.95803 Example 48 0.1142 0.1835 0.0634 1.2112-0.25 100.0118 0.2069-97.95805 Example 490.11980.18350.06381.28720.32600.29490.01300.2167-97.49511 Alloy of Example 2 Example 500.11980.18350.06381.28720.32600.29490.01300.2167-97.49513 Example 510.11980.18350.06381.28720.32600.29490.01300.2167-97.49515 Example 520.01200.1835-1.1794-0.11740.00340.1215-98.38281 Alloy of Example 3 Example 530.01200.1835-1.1794-0.11740.00340.1215-98.38283 Alloy of Example 540.01200.1835-1.1794-0.11740.00340.1215-98.38285 Alloy of Example 550.02570.1835-0.9164-0.09720.00270.09250.033298.64881 Alloy of Example 4 Example 560.02570.1835-0.9164-0.09720.00270.09250.033298.64883 Example 570.02570.1835-0.9164-0.09720.00270.09250.033298.64885

[0156] Orange Peel Scratch Example 46○△ Example 47○△ Example 48△× Example 49○△ Example 50○△ Example 51△× Example 52○○ Example 53○○ Example 54△△ Example 55○○ Example 56○○ Example 57△△

[0157] As shown in Tables 9 and 10, it can be seen that the pipe manufacturing process using the alloy compositions of Examples 3 and 4 produced better results than the alloy compositions of Examples 1 and 2. The fact that many orange peels and scratches appeared in Examples 46, 47, 48, 49, 50, and 51 manufactured using the alloy compositions of Examples 1 and 2 can be largely attributed to the fact that zirconium (Zr) was not included in the alloy components. Zirconium (Zr) is a factor that improves corrosion resistance and can resolve stress corrosion cracking. In addition, although the alloy component of Example 3 does not contain zirconium (Zr), the reason why less orange peel and scratches occurred than in Examples 1 and 2 is because the content of chromium (Cr) and titanium (Ti) was lowered. By lowering the chromium (Cr) and titanium (Ti) content, no crystallites are formed inside, which may have resulted in less orange peel and scratches.

[0158] In addition, through Table 10, it can be confirmed that although the alloys have the same composition, the pipes of Examples 46 and 47 are in better condition than those of Example 48. In addition, the pipes of Examples 49 and 50 are in better condition than those of Example 51, and the pipes of Examples 52 and 53 are in better condition than those of Example 54. Similarly, it can be confirmed that the pipes of Examples 55 and 56 are in better condition than those of Example 57.

[0159] This is believed to be due to differences in cross-sectional shrinkage. Higher cross-sectional shrinkage reduces elongation, which can lead to more orange peel and scratches. Therefore, scratches may have occurred in Examples 48, 51, 54, and 57, which had cross-sectional shrinkage rates of 5%. Therefore, it can be seen that a cross-sectional shrinkage rate of 5% or more is meaningless when manufacturing a 12-pi diameter pipe.

[0160] In addition, it was found that the cross-sectional shrinkage ratio was good up to 1% through Examples 46, 49, 52, and 55 of Table 10. Therefore, when manufacturing a pipe with a diameter of 12 pi, it is desirable to designate a cross-sectional shrinkage ratio of 1% as the minimum cross-sectional shrinkage ratio.

[0161]

[0162] (5) Analysis of results for pipes manufactured from aluminum alloy according to extrusion speed

[0163]

[0164] Examples 58, 59, and 60 produced alloys with the composition of Example 1. The production method is as follows.

[0165] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), copper (Cu), manganese (Mn), chromium (Cr), zinc (Zn), and titanium (Ti) were placed in the furnace and melted at 520°C to produce an alloy, followed by degassing, electromagnetic stirring, and tapping, and then casting at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, and extruded at a speed of 0.3 mm / s for Example 58, 1.3 mm / s for Example 59, and 2.3 mm / s for Example 60, and then coiled, drawn, straightened, and cut to produce a pipe.

[0166]

[0167] Examples 61, 62, and 63 produced alloys with the composition of Example 2. The production method is as follows.

[0168] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), copper (Cu), manganese (Mn), magnesium (Mg), chromium (Cr), zinc (Zn), and titanium (Ti) were placed in the furnace and melted at 520°C to produce an alloy, followed by degassing, electromagnetic stirring, and tapping, and then casting at 670°C to produce a billet. Thereafter, the billet was homogenized at 590°C for 5 hours, and extruded at a speed of 0.3 mm / s for Example 61, 1.3 mm / s for Example 62, and 2.3 mm / s for Example 63, and then coiled, drawn, straightened, and cut to produce a pipe.

[0169]

[0170] Examples 64, 65, and 66 produced alloys with the composition of Example 3. The production method is as follows.

[0171] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), manganese (Mn), chromium (Cr), zinc (Zn), and titanium (Ti) were placed in the furnace and melted at 520°C to produce an alloy, followed by degassing, electromagnetic stirring, and tapping, and then casting at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, and then extruded at a speed of 0.3 mm / s for Example 64, 1.3 mm / s for Example 65, and 2.3 mm / s for Example 66, and then coiled, drawn, straightened, and cut to produce a pipe.

[0172]

[0173] Examples 67, 68, and 69 produced alloys with the composition of Example 4. The production method is as follows.

[0174] Aluminum (Al) ingot was first placed in the furnace, and then silicon (Si), iron (Fe), manganese (Mn), chromium (Cr), zinc (Zn), titanium (Ti), and zirconium (Zr) were placed in the furnace and melted at 520°C to produce an alloy. After degassing treatment, electromagnetic stirring, and tapping, the alloy was cast at 670°C to produce a billet. After that, the billet was homogenized at 590°C for 5 hours, and extruded at a speed of 0.3 mm / s for Example 67, 1.3 mm / s for Example 68, and 2.3 mm / s for Example 69, and then coiled, drawn, straightened, and cut to produce a pipe.

[0175]

[0176] Weight Extrusion speed (mm / s) Remarks SiFeCuMnMgCrZnTiZrAl Example 580.11420.18350.06341.2112-0.25100.01180.2069-97.95800.3 Alloy of Example 1 Example 590.11420.18350.06341.2112-0.25100.01180.2069-97.95801.3 Example 600.11420.18350.06341.2112-0.25100.01180.2069-97.95802.3 Example 610.11980.18350.06381.28720.32600.29490.01300.2167-97.49510.3 Alloy of Example 2 Example 620.11980.18350.06381.28720.32600.29490.01300.2167-97.49511.3 Example 630.11980.18350.06381.28720.32600.29490.01300.2167-97.49512.3 Example 640.01200.1835-1.1794-0.11740.00340.1215-98.38280.3 Alloy of Example 3 Example 650.01200.1835-1.1794-0.11740.00340.1215-98.38281.3 Alloy of Example 660.01200.1835-1.1794-0.11740.00340.1215-98.38282.3 Alloy of Example 670.02570.1835-0.9164-0.09720.00270.09250.033298.64880.3 Alloy of Example 4 Example 680.02570.1835-0.9164-0.09720.00270.09250.033298.64881.3 Example 690.02570.1835-0.9164-0.09720.00270.09250.033298.64882.3

[0177] Orange Peel Scratch Example 58○○ Example 59○△ Example 60△× Example 61○○ Example 62○△ Example 63△× Example 64○○ Example 65○○ Example 66△△ Example 67○○ Example 68○○ Example 69△△

[0178] As shown in Tables 11 and 12, it can be seen that the pipe manufacturing process using the alloy compositions of Examples 3 and 4 produced better results than the alloy compositions of Examples 1 and 2. The fact that many orange peels and scratches appeared in Examples 58, 59, 60, 61, 62, and 63 manufactured using the alloy compositions of Examples 1 and 2 can be largely attributed to the fact that zirconium (Zr) was not included in the alloy components. Zirconium (Zr) is a factor that improves corrosion resistance and can resolve stress corrosion cracking. In addition, although the alloy component of Example 3 does not contain zirconium (Zr), the reason why less orange peel and scratches occurred than in Examples 1 and 2 is because the contents of chromium (Cr) and titanium (Ti) were lowered. By lowering the chromium (Cr) and titanium (Ti) content, no crystallites are formed inside, which may have resulted in less orange peel and scratches.

[0179] In addition, through Table 12, it can be confirmed that although the alloys have the same composition, the pipes of Examples 58 and 59 are in better condition than those of Example 60. In addition, the pipes of Examples 61 and 62 are in better condition than those of Example 63, and the pipes of Examples 64 and 65 are in better condition than those of Example 66. Similarly, it can be confirmed that the pipes of Examples 67 and 68 are in better condition than those of Example 69.

[0180] This is believed to be due to differences in extrusion speed. If the extrusion speed is high, the surface temperature rises rapidly, which may cause surface cracks and bursting, and orange peel and scratches may occur concentrated in the areas where surface cracks and bursting occur. Therefore, it can be seen that orange peel and scratches may have occurred in Examples 60, 63, 66, and 69, which had high extrusion speeds, and that an extrusion speed exceeding 1.3 mm / s is meaningless.

[0181] In addition, it was found that the extrusion speed was in good condition up to 0.3 mm / s through Examples 58, 61, 64, and 67 of Table 12. However, since this speed significantly reduces the production volume per hour, an extrusion speed of 1.3 mm / s is appropriate.

[0182]

[0183] In this way, it will be understood by those skilled in the art that the technical configuration of the present invention described above can be implemented in other specific forms without changing the technical idea or essential features of the present invention.

[0184] Therefore, the embodiments described above should be understood as exemplary in all respects and not static, and the scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the present invention.

Claims

1. A non-heat-treatable, high-corrosion-resistant, high-strength aluminum alloy composition comprising 0.1835 parts by weight of iron (Fe), 0.0001 to 0.1500 parts by weight of silicon (Si), 0.0000 to 0.1000 parts by weight of copper (Cu), 0.9000 to 1.5000 parts by weight of manganese (Mn), 0.0000 to 0.3500 parts by weight of magnesium (Mg), 0.0500 to 0.4000 parts by weight of chromium (Cr), 0.0027 to 0.0500 parts by weight of zinc (Zn), 0.0500 to 0.4000 parts by weight of titanium (Ti), 0.0300 to 0.1500 parts by weight of zirconium (Zr), and 96.7500 to 98.8172 parts by weight of aluminum (Al).

2. In paragraph 1, The method for manufacturing the above non-heat-treatable high-corrosion-resistant, high-strength aluminum alloy composition is as follows: The first step is to charge the aluminum (Al) ingot into the furnace and melt it; A second step of manufacturing an alloy by charging and melting silicon (Si), iron (Fe), copper (Cu), manganese (Mn), magnesium (Mg), chromium (Cr), zinc (Zn), titanium (Ti), and zirconium (Zr) into the melted aluminum (Al) ingot; A third step of degassing the above alloy; The fourth step of electronically stirring the above-degassed alloy; The fifth step of pouring the above electronically stirred alloy into the furnace; A sixth step of manufacturing a billet by casting the above-mentioned molten alloy; Step 7 of homogenizing the above billet; Step 8 of extruding the homogenized billet into a pipe; Step 9 of winding the above pipe; Step 10 of drawing the above-mentioned coiled pipe; Step 11 of straightening the above-mentioned pipe; A method for manufacturing a non-heat-treatable, high-strength aluminum alloy composition, comprising the step of cutting the above-mentioned corrected pipe; 3. In paragraph 2, The extrusion ratio in the extrusion of the above 8th step is When manufacturing a pipe with a diameter of 8 pie, the billet cross-sectional area is 100 mm. 2 When manufacturing pipes with a diameter of 12 pi, the billet cross-sectional area is 100 mm. 2 A method for producing a high-corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment, characterized in that the composition maintains a temperature of 99.5 to 311.

4. In paragraph 2, The cross-sectional shrinkage rate during the drawing process of the above 10th step is A method for manufacturing a non-heat-treatable, high-strength, corrosion-resistant aluminum alloy composition, characterized in that when manufacturing a pipe with a diameter of 8 pi, the drawing is 5 to 10%, and when manufacturing a pipe with a diameter of 12 pi, the drawing is 1 to 3%.

5. In paragraph 2, The dissolution of the above first and second steps is It is characterized by being performed at 660~800℃, The casting of the above 6th step is, It is characterized in that the alloy produced in the fifth step is performed at a temperature of 670 to 700°C. The homogenization treatment of the above 7th step is It is characterized by being performed at 590℃ for 5 to 6 hours. The extrusion of the above 8th step is A method for manufacturing a high-corrosion-resistant, high-strength aluminum alloy composition for non-heat treatment, characterized in that it proceeds at a speed of 1 to 3 mm / s.

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