Composite modifier for heat-resistant cast iron and made from cobalt vanadium nickel-silicon calcium alloy supported with nanometre yttrium oxide-ATO, and preparation method thereof

Abstract

The invention relates to a modifier for heat-resistant cast iron, and specifically relates to a composite modifier for heat-resistant cast iron and made from a cobalt vanadium nickel-silicon calcium alloy supported with nanometre yttrium oxide-ATO, and a preparation method thereof. According to the modifier, the dispersibility and the activity of a nanometre material in a melt are improved by virtue of nanometre yttrium oxide and nanometre ATO powder supported by multi-walled carbon nano-tubes with high thermal stability, high specific surface area, high strength and high toughness, and a cobalt vanadium nickel-silicon calcium alloy powder improves the performance of a traditional silicon calcium modifier, thereby improving the toughness and the heat-resistant capacity of the cast iron; and the nanometre material and the composite alloy powder are mutually bonded and supported, so that the utilization rate of the raw materials is greatly increased. The modifier promotes a graphitization progress of the cast iron, and effectively improves the comprehensive mechanical property of the heat-resistant cast iron; and the obtained casting is compact, high in grey level, high in thermal stability, more convenient to use compared with the traditional modifier, and lower in production cost.

Description

technical field [0001] The invention relates to a heat-resistant cast iron modifier, in particular to a cobalt-vanadium-nickel-silicon-calcium alloy loaded nano-yttrium oxide-ATO composite modifier for heat-resistant cast iron and a preparation method thereof. Background technique [0002] Heat-resistant cast iron refers to cast iron used under high temperature conditions. National standards are mainly divided into three types of heat-resistant cast iron: chromium, silicon and aluminum. This type of cast iron has anti-oxidation and anti-growth properties. The increase in service temperature has higher requirements on the performance of the existing heat-resistant cast iron. The existing problems of the current heat-resistant cast iron are mainly manifested in poor thermal conductivity, poor thermal shock resistance, high brittleness, high scrap rate, short service life, etc. In order to solve these problems, it is particularly important to take effective modification treatme...

AI Technical Summary

Problems solved by technology

[0002] Heat-resistant cast iron refers to cast iron used under high temperature conditions. National standards are mainly divided into three types of heat-resistant cast iron: chromium, silicon and aluminum. This type of cast iron has anti-oxidation and anti-growth properties. The increase in service temperature has higher requirements on the performance of the existing heat-resistant cast iron. The existing problems of the current heat-resistant cast iron are mainly manifested in poor thermal conductivity, poor thermal shock resistance, high brittleness, high scrap rate, short service life, etc. In order to solve these problems, it is particularly important to take effective modification treatment before casting of cast iron. At present, alloy elements such as silicon, aluminum, calcium, copper, titanium, niobium and rare earth are used as modification agents to refine the crystal nucleus. , increase the number of crystal nuclei, promote graphite spheroidization, increase density, and improve high-temperature mechanical properties. However, in actual use, there are constraints such as low raw material utilization and high production costs. In recent years, nanomaterials have been used as modifiers. However, due to Due to the structural characteristics of nanomaterials, their dispersion in the melt is poor, and they are easy to float, requiring auxiliary special injection devices, which increases production costs