Casting process of anti-heat-crack vermicular graphite cast iron brake disc

Abstract

The invention provides a casting process of an anti-heat-crack vermicular graphite cast iron brake disc, and relates to the technical field of vermicular graphite cast iron machining. The casting process of the anti-heat-crack vermicular graphite cast iron brake disc mainly comprises the steps of high-temperature heat melting, purification detection, remelting, vermicular inoculation, sand box preheating, rapid casting, staged cooling, cleaning and polishing, and the like. By adoption of the casting process of the anti-heat-crack vermicular graphite cast iron brake disc, the defects of the prior art are overcome, and the wear resistance and corrosion resistance of traditional vermicular graphite cast iron are effectively ensured; and in addition, heat cracks of the brake disc are effectively prevented, the stability of the brake disc is improved, and the brake disc have efficient heat resistance and fatigue resistance.

Description

technical field [0001] The invention relates to the technical field of vermicular graphite cast iron processing, in particular to a casting process for a thermal crack-resistant vermicular graphite cast iron brake disc. Background technique [0002] The brake disc is one of the important parts of the car brake, and it is also an important guarantee for the safety of the car. With the rapid development of the automobile industry, the brake drums are now tending to be replaced by brake discs, and higher requirements are also placed on the brake discs. development in the direction of sex. At present, the materials used for brake discs at home and abroad are mainly HT300, low-alloy gray cast iron and vanadium-titanium gray cast iron, but they generally have the characteristics of low strength and poor thermal fatigue resistance, and hot cracking often occurs in use. Cr, Ni and Mo are often added in the production of low-alloy gray cast iron. Although the tensile strength, wear...

AI Technical Summary

Problems solved by technology

Hot cracking of castings is related to the uneven thickness of the casting itself. There is a temperature difference after the molten metal is poured, and uniform and synchronous cooling of each part cannot be achieved, resulting in the existence of stress, and hot cracks form cracks in the local overheated parts of the casting.

Cracks are the most destructive defects of precision castings. Cracks are not allowed in castings in the acceptance criteria of brake discs. Therefore, it is particularly important to prevent thermal cracks in precision castings of brake discs. The patent application number is CN200510017968.6 "Thermal Cracking Resistant Vermicular Graphite Cast Iron Brake Material and Vermicular Graphite Cast Iron Brake Disc Prepared From It" proposes a formulation of thermal cracking resistant vermicular graphite cast iron material to reduce the thermal cracking of the prepared brake disc, but It mainly improves the metal composition ratio, but cannot improve the internal stress of the brake disc, and the effect of anti-heat cracking is not significant