Method for casting turbocharger encloser casting

Abstract

The invention discloses a method for casting a turbocharger encloser, comprising the following steps: mulling, molding, manufacturing cores, integrating, smelting furnace burden, tapping, nodulizing, inoculating, pouring, cooling, unpacking, cleaning castings and checking product quality; designing a template into one type comprising 2-8 piece; adopting a completely symmetrical template layout; correspondingly arranging two to eight casting cavities; and casting by the slice-type ingate distributed pouring technology: and after melted iron enters a direct pouring gate, the melted iron passes through a filter provided with a ceramic filter screen below the direct pouring gate, and flows into a horizontal pouring gate, and then the melted iron enters the casting cavity via the ingate to fill in the cavity, wherein the pouring temperature is 1380-1460DEG C, and the top end surface of a far-end side opposite to the ingate inlet of the casting in each casting cavity is provided with two heat-insulation dead heads for feeding. The tensile strength of the casting body is more than or equal to 400MPa, the yield strength is more than or equal to 250MPa, the percentage elongation is more than or equal to 15%, the body hardness is 130-180HBS, the metallographic structure ferrite is more than or equal to 90%, the percent of spheroidization is more than or equal to 90%, the size of graphite is 4-7 grades, and no carbide is permitted to exist.

Description

technical field [0001] The invention relates to a casting method, in particular to a casting method of a casing casting of a turbocharger. Background technique [0002] Turbine casing is a key part of marine turbocharger. Due to the harsh working environment of turbocharger, it is necessary to ensure that the internal high-temperature compressed gas is stored in the volute under extremely high pressure. Therefore, the material of the casing parts is required to be of good quality. Tissue compactness and high toughness. [0003] In response to the above requirements, the parts are specified to use the grade of ductile iron QT400-15. The mechanical properties of castings should meet tensile strength ≥ 400MPa, yield strength ≥ 250MPa, elongation ≥ 15%, body hardness 130 ~ 180HBS; metallographic structure requires ferrite ≥ 90%, spheroidization rate ≥ 90%, graphite size 4 ~ Grade 7, carbides are not allowed. Any casting defects are not allowed inside the product. The charact...

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No casting defects are allowed inside the product

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