Silicon-bismuth as-cast pearlitic ductile iron inoculant

Abstract

The invention relates to an auxiliary material in metal smelting, in particular to a nucleating agent for silicon-bismuth casting state pearlite nodular cast iron. The auxiliary material comprises the following compositions in weight portion: 70 to 90 portions of silicon, 5 to 15 portions of FesiMg8Re7, 3 to 7 portions of bismuth and 3 to 7 portions of a fluxing agent. The auxiliary material has the advantages that the auxiliary material obviously improves the amount of pearlite of casting state nodular cast iron, has good spheroidization and small chilling tendency, solves the problem of degradated spheroidization of the nodular cast iron and needs no heat treatment for graphite distortion and obtains a novel nodular cast iron which has fine and round graphite balls and high comprehensive mechanical performance in the casting state.

Description

technical field [0001] The invention relates to an auxiliary material in metal smelting, in particular to a silicon-bismuth cast pearlite ductile iron inoculant. Background technique [0002] In recent years, a lot of research has been done on the production of as-cast pearlitic ductile iron in cupola furnaces, and the production has been successful. However, no suitable method has been found for the use of spheroidizers. The main nodularizers currently used are low-silicon nodularizers and rare earth silicon-magnesium alloys. [0003] For rare earth silicon-magnesium alloys, according to the properties of the elements, manganese is a graphitizing element, and it is easy to segregate, which does not contribute to the formation of pearlite and the improvement of toughness. Titanium is a segregation type anti-spheroidizer element, so this kind of ball The chemical agent has the problems of poor anti-recession and anti-distortion ability, and uneven microstructure and propert...

AI Technical Summary

Problems solved by technology

[0003] For rare earth silicon-magnesium alloys, according to the properties of the elements, manganese is a graphitized element and is easy to segregate, which is not conducive to the formation of pearlite and the improvement of toughness. Titanium is a segregation-type anti-spheroidizer element, so this kind of ball The chemical agent has the problems of poor anti-fading and anti-distortion ability, and uneven microstructure and properties of ductile iron.