Argon gas protection rotary blowing refining method for low-pressure casting of aluminum alloy melt

An aluminum alloy melt and argon protection technology, which is applied in the field of argon blowing and refining aluminum alloy melt, can solve the problems of differences in refining effects, etc., and achieve the effects of reducing oxidation slag inclusions and gas absorption, reducing production costs, and isolating contact Effect

Active Publication Date: 2019-04-16

XIAN SUPERCRYSYAL SCI TECH DEV CO LTD +1

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AI-Extracted Technical Summary

Problems solved by technology

The instability of each factor in the aluminum alloy refin...

Method used

Step 4: after chemical material is finished, aluminum liquid is carried out argon blowing and refining, process parameter is as follows: rotating speed is 300r/min, ventilation rate is 0.4~0.6m3/h, refining temperature 710~720 ℃, refining time 15min; the ventilation rate matches the 9 air outlet holes 1 wi...

Abstract

The invention discloses an argon gas protection rotary blowing refining method for low-pressure casting of aluminum alloy melt. The method comprises the following steps that an aluminum alloy materialis melted; a refining device is adopted for carrying out argon gas blowing refining on molten aluminum after melting is finished, and molten aluminum alloy metal is left to stand after refining is finished; and a mold shell model waits to be poured; and a casting is poured by adopting a low-pressure casting device connected with an air compressor through a low-pressure casting process. The problem that the content of the aluminum alloy melt casted by low-pressure casting is large is solved, the density and pressure bearing capacity of the aluminum alloy are improved, the situation that the metallurgical quality is unstable and even scrapping occurs due to the fact that the aluminum alloy melt is large in gas content is avoided, so that the production cost of castings is greatly reduced; and the hydrogen content of every 100 g of a sample after refining is less than 0.1 mL, and the production efficiency is improved while the gas content of the aluminum alloy melt is reduced.

Technology Topic

Hydrogen contentAluminium alloy +6

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Examples

Experimental program(4)

Example Embodiment

[0043] Example 1

[0044] Take the size 560×245×190mm casting as an example. The material is ZL114A. There are 11 oil pipes in total. There are many bosses and different shapes. The 3D printing sand mold + low pressure casting method is adopted. There are many sand mold blocks. Specific steps are as follows:

[0045] Step 1: The surface of the aluminum alloy material must be dry-blasted, and the material must be baked at 450°C for 1 hour before being used.

[0046] Step 2: Add the aluminum alloy material baked in step 1 to the 150Kg graphite crucible, use the bell jar to cover the crucible mouth during the process of melting, and pass argon into the aluminum alloy crucible at the center of the upper end of the bell jar. The gas inlet must be 5cm above the upper end of the crucible.

[0047] Step 3: Improve the argon cyclone blowing refining device. The structure of the refining device is improved: a vent 2 is opened along the axis of the graphite rod 3, and the diameter of the vent 2 is 14mm. The bottom end of the graphite rod is provided with 9 evenly distributed along the circumference of the graphite rod And the vent 1 with a diameter of 3mm; a baffle is set on one side of the graphite rod 3, and the distance between the baffle and the axial centerline of the graphite plate 3 is 6cm, and the bottom end of the baffle is 20cm higher than the bottom end of the graphite rod. Is to make the vortex more uniform;

[0048] Step 4: After the material is finished, the aluminum liquid is subjected to argon cyclone blowing refining. The process parameters are as follows: the speed is 300r/min, and the air flow rate is 0.4~0.6m 3 /h, the refining temperature is 715±5℃, and the refining time is 15 min.

[0049] Step 5: The slag removal treatment must be carried out all the time during the refining process.

[0050] Step 6: Make the following improvements for the low-pressure pouring equipment: ①, add a dry deaerator device between the compressed air machine and the gas storage tank; ②, add an oil-water separator between the gas storage tank and the low-pressure pouring equipment.

[0051] Step 7: After the refining is completed, the molten aluminum alloy should be allowed to stand for 10 minutes to complete the hydrogen test.

[0052] Step 8: The 3D printed sand mold block is ready to be poured.

[0053] Step 9: The casting is poured by low-pressure pouring equipment connected with a compressed air machine using a low-pressure pouring process. Mold temperature: normal temperature, pouring temperature: 735~745℃, liquid rising and filling speeds are both: 50mm/s, solidification Pressure difference: 38KPa.

[0054] Step: 10: Clean up the sand mold on the surface of the casting in Step 9, remove the pouring riser, and polish the surface of the casting burrs.

[0055] Step 11: Perform X-ray inspection on the castings in Step 10, and complete low-power inspection and suppression experiments.

[0056] According to this method for aluminum alloy refining treatment, there are pits and collapses in the middle of the hydrogen test sample. After the sample is refined, the hydrogen content per 100g sample is 0.08mL, indicating that there is no gas overflow inside the sample; the casting is tested by X-ray The internal metallurgical quality has reached the standard of HB963 Class I castings, and the pinhole grade is less than 1 after the low-power test, and the 4mm thick oil pipe can bear the pressure of 0.8MPa after the pressure test.

Example Embodiment

[0057] Example 2

[0058] Take a 150×130×57mm casting with an overall wall thickness of 8mm as an example. The material is ZL105. The casting has two hydraulic pressure channels. The specific steps are as follows:

[0059] Step 1: The surface of the aluminum alloy material must be dry-blasted, and the material must be baked at 450°C for 1 hour before being used.

[0060] Step 2: Add the aluminum alloy material baked in step 1 to the 150Kg graphite crucible, use the bell jar to cover the crucible mouth during the process of melting, and pass argon into the aluminum alloy crucible at the center of the upper end of the bell jar. The gas inlet must be 5cm above the upper end of the crucible.

[0061] Step 3: Improve the argon cyclone blowing refining device. The structure of the refining device is improved: a vent 2 is opened along the axis of the graphite rod 3, and the diameter of the vent 2 is 14mm. The bottom end of the graphite rod is provided with 9 evenly distributed along the circumference of the graphite rod And the vent 1 with a diameter of 3mm; a baffle is set on one side of the graphite rod 3, and the distance between the baffle and the axial centerline of the graphite plate 3 is 6cm, and the bottom end of the baffle is 20cm higher than the bottom end of the graphite rod. Is to make the vortex more uniform;

[0062] Step 4: After the material is finished, the aluminum liquid is subjected to argon cyclone blowing refining. The process parameters are as follows: the speed is 300r/min, and the air flow rate is 0.4~0.6m 3 /h, refining temperature 715±5℃, refining time 15min.

[0063] Step 5: The slag removal treatment must be carried out all the time during the refining process.

[0064] Step 6: Make the following improvements for the low-pressure pouring equipment: ①, add a dry deaerator device between the compressed air machine and the gas storage tank; ②, add an oil-water separator between the gas storage tank and the low-pressure pouring equipment.

[0065] Step 7: After the refining is completed, the molten aluminum alloy should be allowed to stand for 10 minutes to complete the hydrogen test.

[0066] Step 8: The mold shell shape is to be poured.

[0067] Step 9: The castings are poured by low-pressure pouring equipment connected with a compressed air machine using low-pressure pouring technology. Mold temperature: normal temperature, pouring temperature: 725~735°C, liquid rising and filling speeds are both: 80mm/s, solidification Pressure difference: 35KPa.

[0068] Step: 10: Clean the surface mold shell of the casting in step 9, remove the pouring riser, and polish the surface burrs of the casting.

[0069] Step 11: Perform X-ray inspection on the castings in Step 10, and complete low-power inspection and suppression experiments.

[0070] According to this method for aluminum alloy refining treatment, there are pits in the middle of the hydrogen test sample and some collapse. After the sample is refined, the hydrogen content per 100g sample is 0.07mL; the internal metallurgical quality of the casting is tested by X-ray and reaches the HB963 Class I casting standard. The pinhole level of the low power test is less than level 1, and the 8mm thick oil pipe can withstand the hydraulic pressure of 0.8MPa after the pressure test.

Example Embodiment

[0071] Example 3

[0072] By size Take a casting with an overall wall thickness of 16mm as an example. The material is ZL114A. The casting is in the shape of a basin with a large arc and a hollow cavity. The specific steps are as follows:

[0073] Step 1: The surface of the aluminum alloy material must be dry-blasted, and the material must be baked at 450°C for 1 hour before being used.

[0074] Step 2: Add the aluminum alloy material baked in step 1 to the 150Kg graphite crucible, use the bell jar to cover the crucible mouth during the process of melting, and pass argon into the aluminum alloy crucible at the center of the upper end of the bell jar. The gas inlet must be 5cm above the upper end of the crucible.

[0075] Step 3: Improve the argon cyclone blowing refining device. The structure of the refining device is improved: a vent 2 is opened along the axis of the graphite rod 3, and the diameter of the vent 2 is 14mm. The bottom end of the graphite rod is provided with 9 evenly distributed along the circumference of the graphite rod And the vent 1 with a diameter of 3mm; a baffle is set on one side of the graphite rod 3, and the distance between the baffle and the axial centerline of the graphite plate 3 is 6cm, and the bottom end of the baffle is 20cm higher than the bottom end of the graphite rod. Is to make the vortex more uniform;

[0076] Step 4: After the material is finished, the aluminum liquid is subjected to argon cyclone blowing refining. The process parameters are as follows: the speed is 300r/min, and the air flow rate is 0.4~0.6m 3 /h, refining temperature 715±5℃, refining time 15min.

[0077] Step 5: The slag removal treatment must be carried out all the time during the refining process.

[0078] Step 6: Make the following improvements for the low-pressure pouring equipment: ①, add a dry deaerator device between the compressed air machine and the gas storage tank; ②, add an oil-water separator between the gas storage tank and the low-pressure pouring equipment.

[0079] Step 7: After the refining is completed, the molten aluminum alloy should be allowed to stand for 10 minutes to complete the hydrogen test.

[0080] Step 8: The mold shell shape is to be poured.

[0081] Step 9: The casting is poured by low-pressure pouring equipment connected with a compressed air machine using low-pressure pouring technology. Mold temperature: normal temperature, pouring temperature: 735~740℃, liquid rising and filling speed are both: 100mm/s, solidification Pressure difference: 45KPa.

[0082] Step 10: Clean the surface mold shell of the casting in step 9, remove the pouring riser, and polish the surface burrs of the casting.

[0083] Step 11: Perform X-ray inspection on the castings in Step 10, and complete low-power inspection and suppression experiments.

[0084] According to this method for aluminum alloy refining treatment, there is a depression in the middle of the hydrogen test sample, and the hydrogen content per 100g sample after the sample is refined is 0.09mL; the internal metallurgical quality of the casting is tested by X-ray and reaches the HB963 Class I casting standard. The pinhole level of the low power test is less than level 1. After the airflow test, the 4mm thick oil pipe can withstand the air pressure of 0.9MPa.

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Argon gas protection rotary blowing refining method for low-pressure casting of aluminum alloy melt

AI-Extracted Technical Summary

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Example Embodiment

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Description & Claims & Application Information

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