Manufacturing method of long-life forged aluminum alloy wheel
Technical Field
The invention relates to the technical field of aluminum alloy wheels, in particular to a manufacturing method of a long-service-life forged aluminum alloy wheel.
Background
In recent years, with the development of the automobile industry, more and more commercial cards and passenger cars select to install forged aluminum alloy wheels, so that the industry of the forged aluminum alloy wheels is promoted to develop rapidly. Although the forged wheel has the advantages of light weight, fuel saving and the like, the production process is complex, the cost is relatively high, and therefore in consideration of the fact that the aluminum alloy has an anti-oxidation function, the forged aluminum alloy wheel manufacturer generally produces the wheel with two states of finish turning and polishing, wherein the wheel is not coated on the surface, and the wheel in the two states has the problems of poor wear resistance, easy corrosion and oxidation, short service life and the like along with the increase of the service life. Thus, only increasing the life of the wheel, increasing the wear, corrosion and oxidation resistance of the wheel, can the market share be increased in a highly competitive market.
Disclosure of Invention
In order to solve the technical problems, the invention provides a method for manufacturing a long-life forged aluminum alloy wheel, which is characterized in that a wheel surface treatment process is added to strengthen the surface of the wheel, so that the forged aluminum alloy wheel with long service life, wear resistance, corrosion resistance and oxidation resistance is obtained.
In order to realize the purpose, the invention is realized by adopting the following technical scheme:
a manufacturing method of a long-life forged aluminum alloy wheel comprises the following operation steps:
s1, bar heating: heating the aluminum bar in a bar heating furnace for at least more than 100min, and discharging the bar;
s2, forging: forging the heated bar stock in a single step on a press at the forging die temperature of 370-390 ℃ to manufacture a circular forging stock with a rim leg;
s3, punching and flaring: placing the forged blank with the rim legs facing upwards on a press machine, expanding the rim legs by a certain angle by using an expanding block, and punching the central part of the forged blank by using a punch;
s4, cleaning and cooling: after flaring and punching, the forging stock enters a cleaning line and is cleaned by room temperature water;
s5, spinning: placing the cleaned flaring forging stock on a spinning lower die, compacting the forging stock by a tail top, rotating the forging stock along with the lower die at the rotating speed of 500 plus 600r/min in the spinning process, and performing rim forming spinning on the forging stock by a spinning wheel;
s6, heat treatment: carrying out heat treatment in a mode of solid solution, quenching and artificial aging;
s7, rough turning: carrying out rough turning on the spinning rough blank by using a vertical lathe;
s8, surface roll finishing: on a lathe, performing full-barreling on the front side of the wheel, the back cavity of the wheel and the outer rim by using a barreling tool, wherein a barreling tool bit is always in the normal direction of a machined profile during machining;
s9, drilling and milling a window: milling a window, drilling a bolt hole and a valve hole by using a machining center;
s10, surface wire drawing: drawing wires on the front surface and the back cavity (except bolt holes, valve holes and windows) of the wheel, placing the wheel on a wire drawing machine, fixing a central hole, and drawing the wires by stably rotating the wire drawing machine at a constant speed;
s11, surface passivation: and (3) soaking the degreased and pure-water-washed forged aluminum alloy wheel in a passivation solution, washing with pure water after passivation, and drying.
As a preferable technical scheme, in the step S1, the aluminum bar is a 6061 aluminum bar, and the tapping temperature of the bar stock is 460-506 ℃.
As a preferable technical solution, the press in step S2 is a 6000 ton press, and the press in step S3 is a 315 ton press.
As a preferable technical scheme, the solid solution temperature in the step S6 is 520-560 ℃, the solid solution time is 180-200 min, the quenching water temperature is kept at 55-65 ℃, the quenching transfer time is within 15S, and the water retention time is 260-300S; the artificial aging temperature is 150-200 ℃, and the time is 5-10 h.
As a preferable technical scheme, the solid solution temperature is 540 ℃, the solid solution time is 191min, the quenching water temperature is kept at 60 ℃, the quenching transfer time is within 10s, and the retention time in water is 280 s; the artificial aging temperature is 177 ℃, and the time is 7.5 h.
As a preferable technical scheme, the rotational speed of the roll finishing in the step S8 is 500-600R/min, the feeding amount is 0.25-0.35mm/R, the diameter of the used roll finishing cutter head is 2mm, and the roughness of the wheel surface after the roll finishing reaches R0.8.
As a preferable technical scheme, in the step S10, the rotation speed of the wire drawing machine is controlled to be 200-.
As a preferable technical scheme, in the step S11, the passivation solution is hexavalent chromium-free passivation solution, the concentration of the passivation solution is 2-3% by mass, the temperature is 30-40 ℃, the pH value is 3.8-4.2, and the passivation time is 2-4 min.
Compared with the prior art, the invention has the beneficial effects that: the manufacturing process comprises the steps of heating a bar material → forging → expanding a punched hole → washing and cooling → spinning → heat treatment → rough turning → surface roll finishing → drilling a bolt hole and milling a window → surface drawing → surface passivation, wherein the surface roll finishing is realized by applying a certain pressure to the surface of the wheel through a high-hardness roll finishing cutter, plastically deforming the surface layer metal at normal temperature and improving the surface hardness of the wheel through work hardening, so that the service life of the forged aluminum alloy wheel is prolonged; the surface wire drawing is to grind the surface of the wheel into lines similar to rules by grinding, so that the problem of surface scratch before the wheel is scratched can be covered, and a certain decorative effect can be achieved; the surface passivation utilizes the passivation solution to form a passivation film on the surface of the wheel, and the passivated forged aluminum alloy wheel has better corrosion resistance and oxidation resistance. Compared with the existing manufacturing process of the forged aluminum alloy, the hardness of the forged aluminum alloy wheel manufactured by the invention is improved by about 25%, the radial fatigue test reaches more than 400 ten thousand turns, and the salt spray CASS test reaches 168 hours without corrosion.
Drawings
FIG. 1 is a schematic view of the forming process of the method of the present invention for producing a long life forged aluminum alloy wheel;
FIG. 2 is a schematic view of the roll finishing process of the method for producing a long-life forged aluminum alloy wheel of the present invention.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
The manufacturing method of the long-life forged aluminum alloy wheel disclosed by the invention comprises the following process steps as shown in figure 1: heating a bar material → forging → expanding a punched hole → washing and cooling → spinning → heat treatment → rough turning → surface rolling → drilling a bolt hole and milling a window → surface drawing → surface passivation, aiming at the problems that the aluminum alloy wheel is poor in wear resistance, easy to corrode and oxidize, short in service life and the like, the surface of the wheel is strengthened by adding a wheel surface treatment process, so that the forged aluminum alloy wheel with long service life, wear resistance, corrosion resistance and oxidation resistance is obtained; the surface roll finishing is to apply a certain pressure to the surface of the wheel by a high-hardness roll finishing cutter, the surface layer metal is subjected to plastic deformation at normal temperature, and the surface hardness of the wheel is improved by work hardening, so that the service life of the forged aluminum alloy wheel is prolonged. The surface wire drawing is to grind the surface of the wheel to form lines similar to regular lines, which can not only cover the scratch problem of the prior wheel surface, but also play a certain role in decoration. The surface passivation utilizes the passivation solution to form a passivation film on the surface of the wheel, and the passivated forged aluminum alloy wheel has better corrosion resistance and oxidation resistance.
Example 1
As shown in fig. 1 to 2, a method for manufacturing a long-life forged aluminum alloy wheel includes the following steps:
s1, bar heating: 6061 heating the aluminum bar in a bar heating furnace for 110min, wherein the tapping temperature of the bar is 460 ℃;
s2, forging: forging the heated bar stock in a single step at the temperature of 370 ℃ on a 6000-ton press to manufacture a circular forging stock with rim legs;
s3, punching and flaring: on a 315t press machine, the forged blank rim legs are placed upwards, the rim legs are expanded by a certain angle through an expanding block, and meanwhile, the punch punches the center of the forged blank, so that the forged blank in the subsequent spinning process is placed on a spinning die and the blank is positioned.
S4, cleaning and cooling: after flaring and punching, the forging stock enters a cleaning line and is cleaned by room temperature water;
s5, spinning: placing the cleaned flaring forging stock on a spinning lower die, compacting the forging stock by a tail top, rotating the forging stock along with the lower die at the rotating speed of 500r/min in the spinning process, and performing rim forming spinning on the forging stock by a spinning wheel;
s6, heat treatment: carrying out heat treatment by adopting a mode of solid solution, quenching and artificial aging, wherein the solid solution temperature is 520 ℃, the solid solution time is 200min, the quenching water temperature is kept at 55 ℃, the quenching transfer time is within 15s, and the water retention time is 260 s; the artificial aging temperature is 150 ℃, and the time is 10 h;
s7, rough turning: carrying out rough turning on the spinning rough blank by using a vertical lathe;
s8, surface roll finishing: on a lathe, a burnishing cutter is used for performing full burnishing on the front surface of a wheel, the back cavity of the wheel and an outer rim, and a burnishing cutter head is always in the normal direction of a machined profile during machining, and the main technological parameters are as follows: the rotating speed is 500R/min, the feeding amount is 0.35mm/R, the diameter of the used barreling cutter head is 2mm, the roughness of the wheel surface after barreling reaches R0.8, and the wire drawing lines in the subsequent wire drawing process are uniform.
S9, drilling and milling a window: milling a window, drilling a bolt hole and a valve hole by using a machining center;
s10, surface wire drawing: carrying out wire drawing treatment on the front surface and the back cavity (except bolt holes, valve holes and windows) of the wheel, placing the wheel on a wire drawing machine, fixing a central hole, stably rotating the wire drawing machine at a constant speed for wire drawing, firstly controlling the rotating speed of the wire drawing machine to be 200r/min, carrying out coarse wire drawing by using 60-mesh abrasive paper, then adjusting the rotating speed of the wire drawing machine to be 400r/min, and then carrying out fine wire drawing by using 120-mesh abrasive paper;
s11, surface passivation: and (3) soaking the degreased and pure-water-washed forged aluminum alloy wheel in a passivation solution, wherein the passivation solution is a hexavalent-chromium-free passivation solution, the concentration of the passivation solution is 2% by mass, the temperature is 30 ℃, the pH value is 3.8, and the passivation time is 4min, and after passivation, washing with pure water and drying.
Example 2
A manufacturing method of a long-life forged aluminum alloy wheel comprises the following operation steps:
s1, bar heating: 6061 heating the aluminum bar in a bar heating furnace for 120min, wherein the tapping temperature of the bar is 480 ℃;
s2, forging: performing single-step forging on the heated bar stock on a 6000-ton press at the forging die temperature of 380 ℃ to manufacture a circular forging stock with rim legs;
s3, punching and flaring: placing the forged blank with the rim legs facing upwards on a 315t press, expanding the rim legs by a certain angle by using an expanding block, and punching the central part of the forged blank by using a punch;
s4, cleaning and cooling: after flaring and punching, the forging stock enters a cleaning line and is cleaned by room temperature water;
s5, spinning: placing the cleaned flaring forging stock on a spinning lower die, pressing the forging stock by a tail top, rotating the forging stock along with the lower die at the rotation speed of 550r/min in the spinning process, and performing rim forming spinning on the forging stock by a spinning wheel;
s6, heat treatment: carrying out heat treatment by adopting a mode of solid solution, quenching and artificial aging, wherein the solid solution temperature is 540 ℃, the solid solution time is 191min, the quenching water temperature is kept at 60 ℃, the quenching transfer time is within 15s, and the water retention time is 280 s; the artificial aging temperature is 177 ℃, and the time is 7.5 h;
s7, rough turning: carrying out rough turning on the spinning rough blank by using a vertical lathe;
s8, surface roll finishing: on a lathe, a burnishing cutter is used for performing full burnishing on the front surface of a wheel, the back cavity of the wheel and an outer rim, and a burnishing cutter head is always in the normal direction of a machined profile during machining, and the main technological parameters are as follows: the rotating speed is 550R/min, the feeding amount is 0.3mm/R, the diameter of the used roll finishing cutter head is 2mm, and the roughness of the wheel surface after roll finishing reaches R0.8.
S9, drilling and milling a window: milling a window, drilling a bolt hole and a valve hole by using a machining center;
s10, surface wire drawing: carrying out wire drawing treatment on the front surface and the back cavity (except bolt holes, valve holes and windows) of the wheel, placing the wheel on a wire drawing machine, fixing a central hole, stably rotating the wire drawing machine at a constant speed for wire drawing, firstly controlling the rotating speed of the wire drawing machine to be 250r/min, carrying out coarse wire drawing by using 60-mesh abrasive paper, then adjusting the rotating speed of the wire drawing machine to be 450r/min, and then carrying out fine wire drawing by using 120 meshes;
s11, surface passivation: and (3) soaking the degreased and pure water washed forged aluminum alloy wheel in a passivation solution, wherein the passivation solution is hexavalent chromium-free passivation solution, the concentration of the passivation solution is 2.5% by mass, the temperature is 35 ℃, the pH value is 4.0, the passivation time is 3min, and the passivated aluminum alloy wheel is washed by pure water and then dried.
Example 3
A manufacturing method of a long-life forged aluminum alloy wheel comprises the following operation steps:
s1, bar heating: 6061 heating the aluminum bar in a bar heating furnace for 100min, wherein the tapping temperature of the bar is 506 ℃;
s2, forging: performing single-step forging on the heated bar stock on a 6000-ton press at the forging die temperature of 390 ℃ to manufacture a circular forging stock with a rim leg;
s3, punching and flaring: placing the forged blank with the rim legs facing upwards on a 315t press, expanding the rim legs by a certain angle by using an expanding block, and punching the central part of the forged blank by using a punch;
s4, cleaning and cooling: after flaring and punching, the forging stock enters a cleaning line and is cleaned by room temperature water;
s5, spinning: placing the cleaned flaring forging stock on a spinning lower die, pressing the forging stock by a tail top, rotating the forging stock along with the lower die at the rotating speed of 600r/min in the spinning process, and performing rim forming spinning on the forging stock by a spinning wheel;
s6, heat treatment: carrying out heat treatment by adopting a solid solution, quenching and artificial aging mode, wherein the solid solution temperature is 560 ℃, the solid solution time is 180min, the quenching water temperature is kept 65 ℃, the quenching transfer time is within 15s, and the water retention time is 300 s; the artificial aging temperature is 200 ℃ and the time is 5 h;
s7, rough turning: carrying out rough turning on the spinning rough blank by using a vertical lathe;
s8, surface roll finishing: on a lathe, a burnishing cutter is used for performing full burnishing on the front surface of a wheel, the back cavity of the wheel and an outer rim, and a burnishing cutter head is always in the normal direction of a machined profile during machining, and the main technological parameters are as follows: the rotating speed is 600R/min, the feeding amount is 0.25mm/R, the diameter of the used roll finishing cutter head is 2mm, and the roughness of the surface of the wheel after roll finishing reaches R0.8;
s9, drilling and milling a window: milling a window, drilling a bolt hole and a valve hole by using a machining center;
s10, surface wire drawing: carrying out wire drawing treatment on the front surface and the back cavity (except bolt holes, valve holes and windows) of the wheel, placing the wheel on a wire drawing machine, fixing a central hole, stably rotating the wire drawing machine at a constant speed for wire drawing, firstly controlling the rotating speed of the wire drawing machine to be 300r/min, carrying out coarse wire drawing by using 60-mesh abrasive paper, then adjusting the rotating speed of the wire drawing machine to be 500r/min, and then carrying out fine wire drawing by using 120-mesh abrasive paper;
s11, surface passivation: and (3) soaking the degreased and pure water washed forged aluminum alloy wheel in a passivation solution, wherein the passivation solution is hexavalent-chromium-free passivation solution, the concentration of the passivation solution is 3% by mass, the temperature is 40 ℃, the pH value is 4.2, the passivation time is 2min, and the forged aluminum alloy wheel is washed by pure water and then dried after passivation.
The aluminum alloy wheels of examples 1-3 of the present invention were subjected to hardness measurement, radial fatigue test, and salt spray CASS test, and compared with the existing forged aluminum alloy wheels, the results are shown in table 1:
TABLE 1 comparison of hardness, life and corrosion resistance of aluminum alloy wheels
The test results show that compared with the existing aluminum alloy forging manufacturing process, the hardness of the forged aluminum alloy wheel manufactured by the invention is improved by about 25 percent, the radial fatigue test reaches more than 400 ten thousand turns, and the salt spray CASS test reaches 168 hours without corrosion
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.