Process for grain refinement of 6061 aluminum alloy ring piece

Abstract

The invention provides a 6061 aluminum alloy ring grain refinement process which comprises the following steps: firstly, heating a 6061 aluminum alloy slab ingot, and carrying out four upsetting and four drawing to obtain a free forge piece; performing punching, chambering and ring rolling on the free forge piece obtained in the previous step to obtain a ring piece; and finally, carrying out solid solution quenching and aging treatment on the ring piece obtained in the previous step to obtain the 6061 aluminum alloy ring piece. According to the grain refinement technology, the problem that grains of a large ring piece are coarse is solved, and the grains of the ring piece are finer; low-temperature cogging is adopted, and equal-pass deformation is combined for four-upsetting and four-drawing, so that crystal grains are uniformly refined; and crystal grain growth is controlled through low-temperature solid solution. And the method is simple and clear in process, high in controllability, high in field executability, easy to implement and more suitable for popularization and application of industrial large-scale production.

Description

Technical Field

[0001] The invention belongs to the technical field of 6 series 6061 aluminum alloy ring preparation, and relates to a method for refining 6061 aluminum alloy ring grains, and in particular to a process for refining 6061 aluminum alloy ring grains. Background Art

[0002] 6061 aluminum alloy has many magnesium and silicon alloy characteristics and forms Mg2Si phase. It has excellent processing performance, excellent welding characteristics and electroplating performance, good corrosion resistance, high toughness and no deformation after processing, dense material without defects and easy polishing, easy color film, excellent oxidation effect and other excellent characteristics. Therefore, it is widely used in various industrial structural parts that require certain strength and high corrosion resistance, such as manufacturing trucks, tower buildings, ships, trams, and railway vehicles, and aerospace fixtures, electrical fixtures, communications, automation machinery parts, precision machining, mold manufacturing, electronics and precision instruments, SMT, PC board solder carriers and other fields.

[0003] 6061 aluminum alloy rings are one of the important types of 6061 aluminum alloys, mainly used in the aerospace field, and have higher performance requirements than general civilian products. However, the 6061 aluminum alloy rings prepared by the existing process are prone to coarse grains, which cannot meet the flaw detection requirements of GB6519-2013A level and do not meet the mechanical properties required by the rings.

[0004] Therefore, how to find a more suitable way to refine the grains of 6061 aluminum alloy rings and solve the above-mentioned technical problems arising in the existing preparation process of 6061 aluminum alloy rings has become one of the urgent problems to be solved by many front-line researchers in the industry. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a method for refining the grains of 6061 aluminum alloy rings, in particular, a process for refining the grains of 6061 aluminum alloy rings. The grain refining process provided by the present invention adopts low-temperature blanking, combined with four-piercing and four-drawing with equal deformation, to uniformly refine the grains; and then controls the growth of grains through low-temperature solid solution, thereby solving the problem of coarse grains in large rings. Moreover, the process is simple and clear, with strong controllability, high on-site executability, and easy to implement, making it more suitable for promotion and application in industrial-scale production.

[0006] The present invention provides a process for grain refinement of a 6061 aluminum alloy ring, comprising the following steps:

[0007] 1) After heating the 6061 aluminum alloy flat ingot, it undergoes four-stage and four-stage drawing to obtain a free forging;

[0008] The temperature of the 6061 aluminum alloy ingot after heating is 430-450° C.

[0009] The first pier of the four piers and four pulls has a pier thickness ratio of 0.4 to 0.6;

[0010] The length ratio of the first draw of the four-pier four-draw is 2.0-2.3;

[0011] 2) The free forgings obtained in the above steps are punched, expanded and ring-rolled to obtain a ring;

[0012] 3) The ring obtained in the above steps is subjected to solution quenching and aging treatment to obtain a 6061 aluminum alloy ring;

[0013] The solution treatment temperature of the solution quenching is 520-535°C;

[0014] The 6061 aluminum alloy, by mass percentage, includes:

[0015] Si: 0.5%~0.76%;

[0016] Fe: 0.1%~0.3%;

[0017] Cu: 0.23%~0.4%;

[0018] Mg: 0.9%~1.10%;

[0019] Cr: 0.04%~0.10%;

[0020] Mn: ≤0.04%;

[0021] Zn: ≤0.09%;

[0022] Ti: ≤0.10%;

[0023] The balance is aluminum.

[0024] Preferably, the temperature of the 6061 aluminum alloy ingot after heating is 430-450°C;

[0025] The width of the 6061 aluminum alloy flat ingot is 1490-1510 mm;

[0026] The height of the 6061 aluminum alloy slab is 470-510 mm.

[0027] Preferably, the forging temperature of the four-pier and four-draw process is ≥400°C;

[0028] The final forging temperature of the four-pier and four-draw process is ≥350°C;

[0029] The first pier of the four piers and four pulls has a pier thickness ratio of 0.4 to 0.6;

[0030] The length ratio of the first draw of the four-pier four-draw is 2.0-2.3.

[0031] Preferably, the pier thickness ratio of the second pier of the four-pier four-pull is 0.4-0.6;

[0032] The draw length ratio of the second draw of the four-pier four-draw is 2.0-2.3.

[0033] Preferably, the pier thickness ratio of the third pier of the four piers and four pulls is 0.4-0.6;

[0034] The draw length ratio of the third draw of the four-pier four-draw is 2.0-2.3.

[0035] Preferably, the pier thickness ratio of the fourth pier of the four piers and four pulls is 0.4-0.6;

[0036] The length ratio of the fourth strand of the four-pier and four-stretch is 2.0-2.3.

[0037] Preferably, the ring rolling start forging temperature is greater than or equal to 400°C;

[0038] The final forging temperature of the ring rolling is greater than or equal to 350°C.

[0039] Preferably, the solution treatment temperature of the solution quenching is 520-535°C;

[0040] The solution treatment time of the solution quenching is 320-390 min;

[0041] The quenching method of the solution quenching includes water cooling.

[0042] Preferably, the temperature of the aging treatment is 162-168°C;

[0043] The aging treatment time is 590-610 min.

[0044] The present invention provides a process for grain refinement of 6061 aluminum alloy rings, comprising the following steps: firstly, heating a 6061 aluminum alloy flat ingot, subjecting it to four-piercing and four-drawing, to obtain a free forging; then subjecting the free forging obtained in the above steps to punching, hole expansion and ring rolling, to obtain a ring; finally, subjecting the ring obtained in the above steps to solid solution quenching and aging treatment, to obtain a 6061 aluminum alloy ring. Compared with the prior art, the present invention particularly uses a 6061 aluminum alloy flat ingot as a raw material, and the refined grains are finer than those of round ingots, and low-temperature blanking is used, combined with equal-pass deformation, four-piercing and four-drawing, to uniformly refine the grains; and then low-temperature solid solution is used to control the grain growth.

[0045] The process for grain refinement of 6061 aluminum alloy rings provided by the present invention solves the problem of coarse grains of large rings. Round ingots are replaced by flat ingots, which have finer grains than round ingots. Low-temperature cogging is adopted, combined with four-piercing and four-pulling with equal deformation, to make the grains uniformly refined. Then, low-temperature solid solution is used to control grain growth. The present invention can solve the problem of poor mechanical properties caused by coarse grains of 6061 aluminum alloy, thereby solving the problem of unqualified flaw detection caused by coarse grains of 6061 aluminum alloy. Moreover, the process is simple and clear, with strong controllability, high on-site executability, and easy to implement, making it more suitable for promotion and application of industrial-scale production.

[0046] Experimental results show that the 6061 aluminum alloy ring prepared by the present invention has fine and uniform grain structure and high mechanical properties, thus meeting application requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Example 1 of the present invention;

[0048] Figure 2 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Example 2 of the present invention;

[0049] Figure 3 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Example 3 of the present invention;

[0050] Figure 4 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Comparative Example 1 of the present invention;

[0051] Figure 5 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Comparative Example 2 of the present invention;

[0052] Figure 6 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Comparative Example 3 of the present invention;

[0053] Figure 7 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Comparative Example 4 of the present invention;

[0054] Figure 8 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Comparative Example 5 of the present invention. DETAILED DESCRIPTION

[0055] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.

[0056] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0057] There is no particular restriction on the purity of all raw materials in the present invention. The present invention preferably uses industrial pure materials or materials with conventional purity requirements in the field of 6061 aluminum alloy ring preparation.

[0058] The brands and abbreviations of all raw materials of the present invention are conventional brands and abbreviations in the art. Each brand and abbreviation is clear and definite in the field of its related use. Those skilled in the art can purchase them from the market or prepare them by conventional methods according to the brands, abbreviations and corresponding uses.

[0059] The abbreviations of the processes used in the present invention are all conventional abbreviations in the field. The specific steps and conventional parameters of each abbreviation are clear and definite in its relevant field. Those skilled in the art can implement them in a conventional manner based on the abbreviations.

[0060] The present invention provides a process for refining the grains of a 6061 aluminum alloy ring, that is, a method for refining the grains of a 6061 aluminum alloy ring, comprising the following steps:

[0061] 1) After heating the 6061 aluminum alloy flat ingot, it undergoes four-stage and four-stage drawing to obtain a free forging;

[0062] 2) The free forgings obtained in the above steps are punched, expanded and ring-rolled to obtain a ring;

[0063] 3) The ring obtained in the above steps is subjected to solution quenching and aging treatment to obtain a 6061 aluminum alloy ring.

[0064] The invention first heats a 6061 aluminum alloy flat ingot, and then performs four-forging and four-drawing to obtain a free forging.

[0065] The 6061 aluminum alloy in the present invention preferably includes, by mass percentage:

[0066] Si: 0.5%~0.76%;

[0067] Fe: 0.1%~0.3%;

[0068] Cu: 0.23%~0.4%;

[0069] Mg: 0.9%~1.10%;

[0070] Cr: 0.04%~0.10%;

[0071] Mn: ≤0.04%;

[0072] Zn: ≤0.09%;

[0073] Ti: ≤0.10%;

[0074] The balance is aluminum.

[0075] In the present invention, the added amount of Si is preferably 0.5% to 0.76%, more preferably 0.55% to 0.7%, and more preferably 0.6% to 0.65%.

[0076] In the present invention, the amount of Fe added is preferably 0.1% to 0.3%, more preferably 0.14% to 0.26%, and more preferably 0.18% to 0.22%.

[0077] In the present invention, the added amount of Cu is preferably 0.23% to 0.4%, more preferably 0.27% to 0.36%, and more preferably 0.31% to 0.32%.

[0078] In the present invention, the added amount of Mg is preferably 0.9% to 1.10%, more preferably 0.94% to 1.06%, and more preferably 0.98% to 1.02%.

[0079] In the present invention, the added amount of Cr is preferably 0.04% to 0.10%, more preferably 0.05% to 0.09%, and more preferably 0.06% to 0.08%.

[0080] In the present invention, the amount of Mn added is preferably ≤0.04%, more preferably ≤0.035%, more preferably ≤0.03%, and specifically can be 0.01% to 0.04%.

[0081] In the present invention, the amount of Zn added is preferably ≤0.09%, more preferably ≤0.08%, more preferably ≤0.07%, and specifically can be 0.02% to 0.09%.

[0082] In the present invention, the amount of Ti added is preferably ≤0.10%, more preferably ≤0.09%, more preferably ≤0.08%, and specifically can be 0.02% to 0.10%.

[0083] In the present invention, the temperature of the 6061 aluminum alloy slab after heating is preferably 430-450°C, more preferably 434-446°C, and preferably 438-442°C.

[0084] In the present invention, the width of the 6061 aluminum alloy slab is preferably 1490-1510 mm, more preferably 1494-1506 mm, and more preferably 1498-1502 mm.

[0085] In the present invention, the height of the 6061 aluminum alloy flat ingot is preferably 470-510 mm, more preferably 478-502 mm, and more preferably 486-594 mm. Specifically, the actual specifications of the ingot can be 490×1570×884 mm, the width of the aluminum alloy flat ingot is 1500±100 mm, the height is 490±20 mm, and the length varies with the weight.

[0086] In the present invention, the forging temperature of the four-pier four-draw process is preferably ≥400°C, more preferably ≥420°C, and more preferably ≥450°C.

[0087] In the present invention, the first pier thickness ratio of the four-pier four-pull structure is preferably 0.4-0.6, more preferably 0.44-0.56, and more preferably 0.48-0.52.

[0088] In the present invention, the draw ratio of the first draw of the four-pier four-draw is preferably 2.0-2.3, more preferably 2.05-2.25, and more preferably 2.1-2.2.

[0089] In the present invention, the thickness ratio of the second pier of the four-pier four-pull structure is preferably 0.4-0.6, preferably 0.44-0.56, and more preferably 0.48-0.52.

[0090] In the present invention, the draw ratio of the second draw of the four-pier four-draw is preferably 2.0-2.3, more preferably 2.05-2.25, and more preferably 2.1-2.2.

[0091] In the present invention, the third pier of the four-pier four-pull structure preferably has a pier-to-thickness ratio of 0.4 to 0.6, preferably 0.44 to 0.56, and more preferably 0.48 to 0.52.

[0092] In the present invention, the draw ratio of the third draw of the four-pier four-draw is preferably 2.0-2.3, more preferably 2.05-2.25, and more preferably 2.1-2.2.

[0093] In the present invention, the fourth pier of the four-pier four-pull structure preferably has a pier-to-thickness ratio of 0.4 to 0.6, preferably 0.44 to 0.56, and more preferably 0.48 to 0.52.

[0094] In the present invention, the draw ratio of the fourth draw of the four-pier four-draw is preferably 2.0-2.3, more preferably 2.05-2.25, and more preferably 2.1-2.2.

[0095] The present invention further performs punching, hole expansion and ring rolling on the free forgings obtained in the above steps to obtain a ring.

[0096] In the present invention, the start forging temperature of the ring rolling is preferably greater than or equal to 400°C, more preferably greater than or equal to 420°C, and more preferably greater than or equal to 450°C.

[0097] In the present invention, the final forging temperature of the ring rolling is preferably greater than or equal to 350°C, more preferably greater than or equal to 370°C, and more preferably greater than or equal to 390°C.

[0098] In the present invention, the ring obtained in the above steps is finally subjected to solution quenching and aging treatment to obtain a 6061 aluminum alloy ring.

[0099] In the present invention, the solution treatment temperature of the solution quenching is preferably 520-535°C, more preferably 522-533°C, and more preferably 523-532°C.

[0100] In the present invention, the solution treatment time of the solution quenching is preferably 320-390 min, more preferably 330-380 min, more preferably 340-370 min, and more preferably 350-360 min.

[0101] In the present invention, the quenching method of the solution quenching preferably includes water cooling. Specifically, in the water cooling, the water temperature is ≤30°C, the forging transfer time is ≤15s, the immersion time is ≥15min, the shaking during water cooling is >10 times, and the material spacing is ≥100mm.

[0102] In the present invention, the temperature of the aging treatment is preferably 162-168°C, more preferably 163-167°C, and more preferably 164-166°C.

[0103] In the present invention, the aging treatment time is preferably 590-610 min, more preferably 594-606 min, and more preferably 598-602 min.

[0104] The present invention particularly adopts 6061 aluminum alloy flat ingot as raw material, and the grains after refinement are finer. Low temperature cogging is adopted, and four-pumping and four-drawing with equal deformation are combined to make the grains uniformly refined; and then low temperature solid solution is used to control the growth of grains. Among them, low temperature cogging can effectively retain the phases separated from the alloy part without dissolving back, which becomes the particle point for grain refinement, and then four-pumping and four-drawing with equal deformation are combined to make the grains fully and uniformly refined, and low temperature solid solution is used to reduce the driving force for grain growth, thereby controlling the growth of grains.

[0105] The present invention is to complete and refine the overall technical solution, better improve the grain refinement effect of the 6061 aluminum alloy ring, and then improve the mechanical properties of the ring. The above-mentioned 6061 aluminum alloy ring grain refinement process can specifically include the following steps:

[0106] Flat ingots (control the heating temperature of the ingot) are used to obtain free forgings after four punching and four drawing, and then rings are obtained through punching, hole expansion and ring rolling (control the start forging temperature and final forging temperature). They are solution quenched at a specific temperature and aged at a specific temperature to control the aging time.

[0107] The above content of the present invention provides a process for grain refinement of 6061 aluminum alloy rings. The present invention particularly uses 6061 aluminum alloy flat ingots as raw materials. Compared with round ingots, the refined grains are finer. Low-temperature cogging is used, combined with equal-pass deformation, four-piercing and four-drawing, to make the grains uniformly refined; and then low-temperature solid solution is used to control the grain growth.

[0108] The process for grain refinement of 6061 aluminum alloy rings provided by the present invention solves the problem of coarse grains of large rings. Round ingots are replaced by flat ingots, which have finer grains than round ingots. Low-temperature cogging is adopted, combined with four-piercing and four-pulling with equal deformation, to make the grains uniformly refined. Then, low-temperature solid solution is used to control grain growth. The present invention can solve the problem of poor mechanical properties caused by coarse grains of 6061 aluminum alloy, thereby solving the problem of unqualified flaw detection caused by coarse grains of 6061 aluminum alloy. Moreover, the process is simple and clear, with strong controllability, high on-site executability, and easy to implement, making it more suitable for promotion and application of industrial-scale production.

[0109] Experimental results show that the 6061 aluminum alloy ring prepared by the present invention has fine and uniform grain structure and high mechanical properties, thus meeting application requirements.

[0110] In order to further illustrate the present invention, a method for refining the grains of 6061 aluminum alloy rings provided by the present invention is described in detail in combination with embodiments. However, it should be understood that these embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating processes are given only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention. The protection scope of the present invention is not limited to the following embodiments.

[0111] Example 1

[0112] The flat ingot was heated to 430°C, and four forgings and four drawing were performed according to the forging ratio of 0.5 and the drawing ratio of 2.1 in each pass to obtain a free forging. The 6061 aluminum alloy ring was obtained by punching, expanding and ring rolling. The ring was then solution quenched at 530°C and aged at 165°C for 600 min.

[0113] The 6061 aluminum alloy ring prepared in Example 1 of the present invention was characterized.

[0114] See also Figure 1 , Figure 1This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Example 1 of the present invention.

[0115] Example 2

[0116] The flat ingot was heated to 440°C, and four forgings and four drawing were performed according to the forging ratio of 0.5 and the drawing ratio of 2.2 in each pass to obtain a free forging. The 6061 aluminum alloy ring was obtained by punching, expanding and ring rolling. The ring was then solution quenched at 528°C and aged at 165°C for 600 min.

[0117] The 6061 aluminum alloy ring prepared in Example 2 of the present invention was characterized.

[0118] See also Figure 2 , Figure 2 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Example 2 of the present invention.

[0119] Example 3

[0120] The flat ingot was heated to 420°C, and four forgings and four drawing were performed according to the forging ratio of 0.48 and the drawing ratio of 2.1 in each pass to obtain a free forging. The 6061 aluminum alloy ring was obtained by punching, expanding and ring rolling. The ring was then solution quenched at 530°C and aged at 165°C for 600 min.

[0121] The 6061 aluminum alloy ring prepared in Example 3 of the present invention was characterized.

[0122] See also Figure 3 , Figure 3 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Example 3 of the present invention.

[0123] Comparative Example 1

[0124] The round ingot is heated to 430°C, and four-piercing and four-drawing are performed according to the roughening ratio of each pass of 0.5 and the drawing ratio of 2.1 to obtain a free forging. The 6061 aluminum alloy ring is obtained by punching, expanding and ring rolling. The ring is then solution quenched at 530°C and aged at 165°C for 600 min.

[0125] The 6061 aluminum alloy ring prepared in Comparative Example 1 of the present invention was characterized.

[0126] See also Figure 4 , Figure 4 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Comparative Example 1 of the present invention.

[0127] Comparative Example 2

[0128] The flat ingot was heated to 430°C, and two forgings and two drawing were performed according to the forging ratio of 0.5 and the drawing ratio of 2.1 in each pass to obtain a free forging. The 6061 aluminum alloy ring was obtained by punching, expanding and ring rolling. The ring was then solution quenched at 530°C and aged at 165°C for 600 min.

[0129] The 6061 aluminum alloy ring prepared in Comparative Example 2 of the present invention was characterized.

[0130] See also Figure 5 , Figure 5 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Comparative Example 2 of the present invention.

[0131] Comparative Example 3

[0132] The flat ingot was heated to 430°C, and four forgings and four drawing were performed according to the roughing ratio of 0.4 and the drawing ratio of 1.9 in the first two passes, and the roughing ratio of 0.6 and the drawing ratio of 2.3 in the last two passes to obtain a free forging. The 6061 aluminum alloy ring was obtained by punching, expanding and ring rolling, and then the ring was solution quenched at 530°C and aged at 165°C for 600 min.

[0133] The 6061 aluminum alloy ring prepared in Comparative Example 3 of the present invention was characterized.

[0134] See also Figure 6 , Figure 6 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Comparative Example 3 of the present invention.

[0135] Comparative Example 4

[0136] The flat ingot was heated to 460°C, and four forgings and four drawing were performed according to the forging ratio of 0.5 and the drawing ratio of 2.1 in each pass to obtain a free forging. The 6061 aluminum alloy ring was obtained by punching, expanding and ring rolling. The ring was then solution quenched at 530°C and aged at 165°C for 600 min.

[0137] The 6061 aluminum alloy ring prepared in Comparative Example 4 of the present invention was characterized.

[0138] See also Figure 7 , Figure 7 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Comparative Example 4 of the present invention.

[0139] Comparative Example 5

[0140] The flat ingot was heated to 430°C, and four forgings and four drawing were performed according to the forging ratio of 0.5 and the drawing ratio of 2.1 in each pass to obtain a free forging. The 6061 aluminum alloy ring was obtained by punching, expanding and ring rolling. The ring was then solution quenched at 550°C and aged at 165°C for 600 min.

[0141] The 6061 aluminum alloy ring prepared in Comparative Example 5 of the present invention was characterized.

[0142] See also Figure 8 , Figure 8 This is the metallographic structure diagram of the 6061 aluminum alloy ring prepared in Comparative Example 5 of the present invention.

[0143] The performance of the 6061 aluminum alloy rings prepared in the embodiments of the present invention and the comparative examples was tested.

[0144] See Table 1, which shows the mechanical properties and metallographic structure test data of 6061 aluminum alloy rings prepared in the embodiments of the present invention and the comparative examples.

[0145] Table 1 Mechanical properties and metallographic structure test data of 6061 aluminum alloy rings prepared in the embodiments of the present invention and the comparative examples

[0146]

[0147] The above is a detailed introduction to a 6061 aluminum alloy ring grain refinement process provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and its core ideas of the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including the manufacture and use of any device or system, and the implementation of any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A process for grain refinement of 6061 aluminum alloy rings, characterized in that: The following steps are involved: 1) After heating the 6061 aluminum alloy flat ingot, it undergoes four-stage and four-stage drawing to obtain a free forging; The temperature of the 6061 aluminum alloy ingot after heating is 430-450° C. The first pier of the four piers and four pulls has a pier thickness ratio of 0.4 to 0.6; The length ratio of the first draw of the four-pier four-draw is 2.0-2.3; 2) Punching, expanding and ring rolling the free forgings obtained in the above steps to obtain a ring; 3) The ring obtained in the above steps is subjected to solution quenching and aging treatment to obtain a 6061 aluminum alloy ring; The solution treatment temperature of the solution quenching is 520-535°C; The 6061 aluminum alloy ring comprises, by mass percentage: Si: 0.5%~0.76%; Fe: 0.1%~0.3%; Cu: 0.23%~0.4%; Mg: 0.9%~1.10%; Cr：0.04%~0.10%； Mn: ≤0.04%; Zn: ≤0.09%; Ti: ≤0.10%; The balance is aluminum.

2. The process according to claim 1, characterized in that The width of the 6061 aluminum alloy slab is 1490-1510 mm.

3. The process according to claim 1, characterized in that The height of the 6061 aluminum alloy slab is 470-510 mm.

4. The process according to claim 1, characterized in that The forging temperature of the four-pier four-draw process is ≥400°C; The final forging temperature of the four-pier and four-draw process is ≥350°C.

5. The process according to claim 1, characterized in that The pier thickness ratio of the second pier of the four piers and four pulls is 0.4-0.6; The draw length ratio of the second draw of the four-pier four-draw is 2.0-2.

3.

6. The process according to claim 1, characterized in that The pier thickness ratio of the third pier of the four piers and four pulls is 0.4-0.6; The draw length ratio of the third draw of the four-pier four-draw is 2.0-2.

3.

7. The process according to claim 1, characterized in that The pier thickness ratio of the fourth pier of the four piers and four pulls is 0.4-0.6; The length ratio of the fourth strand of the four-pier and four-stretch is 2.0-2.

3.

8. The process according to claim 1, characterized in that The ring rolling start forging temperature is greater than or equal to 400°C; The final forging temperature of the ring rolling is greater than or equal to 350°C.

9. The process according to claim 1, characterized in that The solution treatment time of the solution quenching is 320-390 min; The quenching method of the solution quenching includes water cooling.

10. The process according to claim 1, characterized in that The temperature of the aging treatment is 162-168°C; The aging treatment time is 590-610 min.

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