A kind of solid solution strengthened ferritic vermicular graphite cast iron and production method thereof

Abstract

The invention discloses solution strengthening ferrite vermicular graphite cast iron and a production method thereof. The matrix structure of the solution strengthening ferrite vermicular graphite cast iron comprises ferrite with the mass percentage larger than 80%, and the ferrite is subjected to solution strengthening through Si. The components of the solution strengthening ferrite vermicular graphite cast iron include, by mass, 2.9-3.5% of C, 3.0-4.8% of Si, 0.0001-0.3% of Mn, 0.0001-0.07% of P, 0.0001-0.2% of Cu, 0.0001-0.1% of Cr, 0.0001-0.1% of Mo, 0.0001-0.02% of Sn, 0.007-0.020% of S, 0.008-0.030% of Mg, 0.010-0.040% of RE and the balance Fe and inevitable microelements, wherein the carbon equivalent needs to be kept at 4.2-4.6% and is equal to the mass percentage of carbon plus one third the mass percentage of silicon. The production method of the solution strengthening ferrite vermicular graphite cast iron comprises the steps of blending and melting, vermicularizing and inoculation treatment and cooling and unpacking. By adoption of the solution strengthening ferrite vermicular graphite cast iron and the production method thereof, the mechanical performance and machining performance of the vermicular graphite cast iron are effectively improved, and meanwhile, the production cost of the vermicular graphite cast iron is reduced.

Description

technical field [0001] The invention belongs to the technical field of metal smelting, and in particular relates to a vermicular graphite cast iron and a production method thereof, in particular to a silicon solid-solution strengthened ferrite vermicular graphite cast iron and a production method thereof. Background technique [0002] Vermicular graphite cast iron is called vermicular graphite cast iron for short. Its graphite is worm-like, and the carbon element in it is mainly precipitated in the form of worm-like graphite. The matrix structure of vermicular graphite cast iron includes ferrite and pearlite: ferrite is an interstitial solid solution of carbon dissolved in α-Fe, ferrite in cast iron exists in the form of flakes, blocks, needles and networks, and pearlite is A layered structure in cast iron consisting of thin layers of ferrite and cementite. In the case of the same graphite form, the tensile strength of vermicular graphite cast iron increases with the increa...

AI Technical Summary

Problems solved by technology

The disadvantage of this method of increasing the strength by increasing the pearlite content is: to increase the pearlite content, Cu, Mo, Sn, Ni and other alloying elements that promote the formation of pearlite must be added, resulting in an increase in production costs; As the content increases, the hardness of the casting also increases, and because the cooling speed of each part of the casting is different, the pearlite content is not the same, which leads to the increase of the hardness difference of each part of the casting, resulting in machining difficulties and increasing machining costs. Precision

[0003] There is no research and elaboration on the application of silicon solid solution strengthening technology on vermicular graphite cast iron in the prior art

And the production method of the high-silicon-molybdenum vermicular graphite cast iron disclosed in the current prior art has higher content and more expensive Mo, which causes its production cost to be too high, which limits its application in common occasions

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