High nickel austenite spheroidal graphite cast iron automobile exhaust branch pipe and casting method

Abstract

The invention relates to a high-nickel austenite nodular graphite cast iron vehicle discharge branch tube and relative casting method. Wherein, said casting method comprises core production, shaping, combining, smelting, irrigating, dropping sand and cleaning casting; while the core production uses low-nitrogen high-temperature cover sand; the inner sand core of discharge branch tube is internal flow sand core; the outer chamber sand core embeds cold iron at the clamp part between two tubes; and it uses side riser and uses the static compressor in irrigation supplied by wet mound sand; the smelting temperature is 1600-1700Deg. C; and it uses magnetite-silica alloy as nodulizer; and uses ferrosilicon and strontium inoculant to inoculate for two times; and it uses large flux and high temperature irrigation. The inventive branch tube has better corrosion-resistance, high-temperature resistance, and non radiation.

Description

technical field [0001] The invention belongs to the technical field of automobile exhaust manifolds, and particularly relates to a high-nickel austenitic ductile iron automobile exhaust manifold and a casting method. Background technique [0002] With the development of social and economic conditions, medium and high-end cars continue to emerge in the market, and their horsepower and emissions have higher and higher requirements for the working conditions of auto parts. Under the working conditions of alternating heat and cold, the strength and plasticity of the exhaust manifold are poor, which is easy to cause deformation and cracking, resulting in insufficient working pressure of the engine, which affects the speed of the car, and in severe cases, the engine fails to work, which cannot meet the requirements of the automobile industry. development, so the material selection requirements are tailored. [0003] High-nickel austenitic ductile iron has many advantages such as ...

AI Technical Summary

Problems solved by technology

Due to the characteristics of high nickel austenitic nodular cast iron molten iron has large surface tension, large shrinkage tendency, fast cooling and poor fluidity, it is used in automobile exhaust manifolds. More, the castings are most prone to shrinkage cavity, shrinkage porosity, insufficient pouring and cold shut defects

Therefore, the casting technology of high-nickel austenitic nodular cast iron in automobile exhaust manifold is not mature enough at home and abroad, and needs to be further developed.

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