Process for improving metallographic structure of piston head and increasing casting production efficiency

Abstract

The invention provides a process for improving the metallographic structure of a piston head and increasing casting production efficiency. The process comprises the steps of: (1) eliminating an exhaust hole and an exhaust nail on a bottom die, and meanwhile reducing the thickness of a wall between the bottom die and a cooling water cavity, respectively subtracting 10mm from the length and the width of a casting head on an outer die, wherein the specifications of the length and the width are respectively 48mm-55mm and 48mm-54mm; and meanwhile, adding 10mm-12mm to the length L2 of the rear part of the outer die, and adding 5mm-8mm to the width D of the rear part of the outer die, wherein the specifications of the length L2 and the width D are respectively 176-mm-195mm and 78mm-85mm; (2) processing a tooling die; (3) preparing for the smelting of an aluminum liquid; (4) assembling and debugging the tooling die; (5) casting in field production; (6) hot treating a piston blank; and (7) detecting the quality of the piston. The invention can refine the metallographic structure of the piston head by 1-2 levels and improve casting efficiency by more than 15%.

Description

technical field [0001] The process technology relates to a casting process method for aluminum alloy casting parts, especially a casting process method for producing an upper core-pulling aluminum alloy piston. Background technique [0002] Most of the ordinary piston casting blanks are cast by gravity casting with core pulling. The cost is high, so at present, the outer mold of piston forming generally adopts a single-side riser structure, and the position of the single-side riser is usually designed on the side with a large thermal pitch circle of the piston body, so as to facilitate the feeding of the piston blank by the heat preservation riser; The bottom mold adopts a structure with vent holes and is forced to cool with water at the same time, but the cooling distance is relatively long, reaching 16-20mm, and the cooling effect is relatively poor. With the above structure, the metallographic structure of the piston is generally at level 2-3, and the primary crystal sil...

AI Technical Summary

Problems solved by technology

[0002] Most of the ordinary piston casting blanks are cast by gravity casting with core pulling. The cost is high, so at present, the outer mold of piston forming generally adopts a single-side riser structure, and the position of the single-side riser is usually designed on the side with a large thermal pitch circle of the piston body, so as to facilitate the feeding of the piston blank by the heat preservation riser; The bottom mold adopts a structure with vent holes and is forced to cool with water at the same time, but the cooling distance is relatively long, reaching 16-20mm, and the cooling effect is relatively poor

With the above structure, the metallographic structure of the piston is generally at level 2-3, and the primary crystal silicon at the head is at 20-30 microns; the feeding time is long, the worker pauses for a long time, and the production efficiency is generally not high; after the piston blank is demoulded, the overall The temperature uniformity is poor, and the overall hardness difference of the piston after casting and quenching is relatively large

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