Method for eliminating coarse grains on surface of aluminum alloy barrel type extrusion part

The invention discloses a method for eliminating coarse grains on the surface of an aluminum alloy barrel type extrusion part. The method includes the steps that in the process of preparing the aluminum alloy barrel type extrusion part, coarse grain structures on the surface of an aluminum alloy bar are turned off firstly, the aluminum alloy bar is then heated, a mold used for extrusion forming issubjected to preheating treatment, and then extrusion forming is conducted on the aluminum alloy bar, and finally, the extrusion part is subjected to quenching and aging treatment, the aluminum alloybarrel type extrusion part without surface coarse grains is prepared. The grains on the surface of the aluminum alloy barrel type extrusion part are uniform and fine, the grain size grade is 1-2, thefatigue strength and the cutting performance of the aluminum alloy barrel type extrusion part are improved, and the quality of an oxide film on the surface of the aluminum alloy barrel type extrusionpart is also improved. 本发明公