Composite modifier for heat resisting cast iron of vanadium iron cobalt-silicon calcium alloy carrying nano zinc sulfide-titanium oxide and preparation method of composite modifier

Abstract

The invention relates to a modifier for heat resisting cast iron, in particular to a composite modifier for heat resisting cast iron of vanadium iron cobalt-silicon calcium alloy carrying a nano zinc sulfide-titanium oxide and a preparation method of the composite modifier. According to the composite modifier, through zinc sulfide and nano titanium oxide which are high in thermal stability, specific area, strength and toughness and are carried by multi-wall carbon nano tubes, the dispersity and activity of nano materials in melt are improved, a large quantity of refined crystal nucleus are generated, the performance of a traditional silico-calcium modifier is improved through vanadium iron cobalt-silicon calcium alloy powder, and the toughness and heat resistance of cast iron are improved; the nano materials are bonded to and carried by the composite alloy powder, so that the utilization rate of raw materials is greatly increased; the graphitizing process of the cast iron is effectively promoted through the modifier, graphite is more refined, the comprehensive mechanical performance of the heat-resistant cast iron is effectively improved, and obtained castings are compact and resistant to thermal shock and thermal oxidation; and compared with the traditional modifier, the modifier is more convenient to use and lower in production cost.

Description

technical field [0001] The invention relates to a modifier for heat-resistant cast iron, in particular to a composite modifier for heat-resistant cast iron loaded with vanadium-iron-cobalt-calcium-silicon alloy and a composite modifier for heat-resistant cast iron. 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 tr...

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