Gray cast iron inoculation process

Abstract

The invention relates to a graphitic cast iron inoculation technology. The technology is to add a composite inoculant of inoculated rare earth barium-calcium alloy with the granularity between 3 and 8 millimeters, silicon-calcium alloy with the granularity less than or equal to 5 millimeters and ferromanganese with the granularity less than or equal to 15 millimeters, which accounts for 0.3 to 0.5 percent of the weight of an iron liquor required to be treated, into a ladle for stokehole treatment. In order to prevent the fact that the inoculant can not enter into the iron liquor to be treated because the inoculant is wrapped by furnace slag, the composite inosulant can be held into a metal box provided with a plurality of vent holes, and the metal box is directly thrown into the ladle under the condition of stokehole treatment. The technology has the advantages that the technology adopts addition of the rare earth barium-calcium alloy, the silicon-calcium alloy and the ferromanganese into the ladle, is favorable for improving the inoculation capability of the iron liquor and strengthening the inoculation effect, can make the strength of graphitic cast iron reach more than 260 MPa, obviously thins pearlite in a substrate, reduces the segment pitch of the pearlite, improves the graphite form, makes the cast iron obtain good graphite tissue, and stably improves the strength of the graphitic cast iron.

Description

technical field [0001] The invention relates to an inoculation treatment process of gray cast iron, which belongs to the technical field of inoculation treatment before molten iron pouring. Background technique [0002] At present, the inoculation treatment process is one of the most economical and effective ways to improve the performance of gray cast iron. Over the years, foundry workers have conducted a lot of experimental research on the composition of inoculants and inoculation methods. So far, nearly a thousand different types of inoculants and corresponding inoculation treatment methods have been developed at home and abroad according to different molten iron quality, casting types, and casting quality requirements. Domestic researchers have conducted systematic research on rare earth composite inoculants, and used them to produce high-carbon equivalent high-strength gray cast iron, and made some progress. However, due to reasons such as poor fertilization ability of...

AI Technical Summary

Problems solved by technology

However, due to reasons such as poor fertilization ability of high-carbon equivalent molten iron, the effect of increasing strength is not significant

In addition, if the pouring time of the molten iron after inoculation treatment is longer, the addition amount will increase correspondingly due to the recession of inoculation, which will relatively increase the production cost