High-strength wear-resistant cast iron and stream inoculation technology thereof

Abstract

The invention discloses a high-strength wear-resistant gray cast iron and an inoculation process thereof, and relates to the technical field of wear-resistant gray cast iron inoculation. The present invention includes the weight ratio of each component as follows: C: 4.28%, Cr: 0.05%, Mn: 1.57%, Si: 0.38%, Ti: 0.38%, P<0.02%, S<0.15%, B: 0.67 %, Ni: 0.96%, Mo: 0.082%, V: 0.11%, Sn: 0.09%, and the rest is Fe. The present invention adopts inoculation treatment in front of the furnace and in the ladle during the manufacture of gray cast iron, mixes and bakes the silicon-barium inoculant and rare earth ferrosilicon to 100-150°C, and then adds them into the molten iron along with the flow of the tapping trough for follow-up Flow inoculation treatment, promotes nucleation, inhibits growth, refines grains, promotes graphitization, reduces whitening tendency; improves the uniformity of the section, improves the mechanical properties of gray cast iron, and improves the wear resistance of gray cast iron.

Description

technical field [0001] The invention belongs to the technical field of inoculation of wear-resistant gray cast iron, and in particular relates to a high-strength wear-resistant gray cast iron and an inoculation process thereof. Background technique [0002] Inoculation treatment refers to adding a small amount of other substances to the liquid metal during the solidification process to promote nucleation, inhibit growth, and achieve the purpose of refining grains. Customarily, adding additives to cast iron is called inoculation treatment, and adding alloys is called modification treatment. Essentially, inoculation treatment mainly affects nucleation and promotes free crystal grains; while modification treatment changes the growth mechanism of crystals, thereby affecting crystal morphology. Gray cast iron is basically a eutectic alloy composed of iron, carbon and silicon, in which carbon mainly exists in the form of graphite. Controlling the morphology and matrix metal stru...

AI Technical Summary

Problems solved by technology

However, when traditional 75Si is used for inoculation, pearlite will be formed at different temperatures, and its hardness will be uneven. Due to the reaction of the inoculant with high-temperature molten iron, silicon dioxide is formed as the primary nucleus of graphite, so that the carbon in the molten iron turns to graphite. However, due to the reduction reaction of silicon oxide, the silicon content in molten iron will gradually decrease, which will reduce the degree of supercooling of molten iron. The smaller the degree of supercooling, the easier it is to transform into a carburizing system.