CN104148579A - Resin sand-produced nodular cast iron paint and preparation method thereof - Google Patents

Abstract

The invention discloses resin sand-produced nodular cast iron paint and a preparation method thereof. The resin sand-produced nodular cast iron paint consists of zircon powder, graphite powder, sodium bentonite, iron oxide powder, silicon iron powder, magnesium oxide and dextrin. The preparation cost is low; the preparation method is simple; flake graphite can be prevented from generating on the surface of a casting; and the yield of the casting is improved.

Description

A kind of resin sand is produced spheroidal graphite cast-iron coating and preparation method

Technical field

The invention belongs to casting technology field, especially relate to a kind of resin sand and produce spheroidal graphite cast-iron coating and preparation method.

Background technology

In spheroidal graphite cast-iron production process, Mian Yuzhong discontinuity surface district, core cavity top layer nodulizing grade is not larger, middle discontinuity surface 2-3 level, and there is 5-6 level in interior cavity surface layer face, product is caused and scrap, and to enterprise, causes greater loss.By foundry goods metallographic is analyzed, find that foundry goods lamella graphite generally appears at foundry goods upper surface and lower surface, in top layer, not only occurred flake graphite, and between flake graphite and globular graphite, have a transition region as thin as a wafer, be quasiflake graphite, the general 1-2mm of sheet layer depth.By foundry goods is carried out to constituent analysis, find that in magnesium iron, sheet China ink layer, this district's sulfur content 0.056% appear in 0.25mm depths, boundary layer, residual magnesium content 0.013%, the dark 0.5-3mm in foundry goods top layer, average sulfur content 0.036%, residual magnesium content 0.035%, foundry goods center sulfur content 0.018%, residual magnesium content 0.046%.According to above data, cast(ing) surface sulfur content is higher.From foundry goods formative technology, analyze, with resin self-setting sand, produce, adopt benzene sulfonic acid class curing agent to solidify, cast iron liquid enters after die cavity, under the effect of high temperature iron liquid, benzene sulfonic acid decomposites sulfurous gas, this gas infiltrates in iron liquid through dope layer, and reacts with magnesium or rare earth in mo(U)ld face iron liquid, has consumed a part of nodularization element, cause nodularization element residual quantity in the iron liquid of top layer lower than the minimum residual quantity that guarantees top layer spheroidization of graphite, thereby occur surperficial flake graphite.Simultaneously, the resin sand alcohol paint that routine is used at present, coating generally can not stop and between foundry goods and casting mold, carries out mass exchange, while containing gasifiable sulfur-bearing composition in casting mold, high temperature iron liquid do with under decomposite sulfurous gas, these gases spread to iron liquid by gap, make sulphur enter foundry goods boundary layer, occur flake graphite.

Summary of the invention

The object of the invention is: for the problem and shortage of above-mentioned existence, provide a kind of cost resin sand low, easy to prepare, that improve casting yield to produce spheroidal graphite cast-iron coating and preparation method.

Technical scheme of the present invention is: a kind of resin sand is produced spheroidal graphite cast-iron coating, following material, consists of, and is by weight percentage: zirconium English powder 40-48%, graphite powder 40-48%, sodium bentonite 3-4%, ferric oxide red powder 3-5%, ferrosilicon powder 2-3%, magnesia 1-2%, dextrin 1-1.5%.

Resin sand is produced a preparation method for spheroidal graphite cast-iron coating, comprises the following steps:

(1) 3-4 part sodium bentonite, 1-1.5 part dextrin are stirred after adding alcohol, then add 40-48 part zirconium English powder, 40-48 part graphite powder, 3-5 part ferric oxide red powder, 2-3 part ferrosilicon powder, 1-2 part magnesia, stir;

(2) with hairbrush, by the above-mentioned coating stirring, evenly brush is on resin-bonded sand cast form surface, and thickness is 0.3-0.5mm, then lights baking, on resin-bonded sand cast form surface, forms dope layer.

The invention has the beneficial effects as follows: in proportioning of the present invention, zirconium English powder, graphite powder are fire-resistant skeleton, sodium bentonite is suspending agent, dextrin is binding agent, can improve coating dry strength, zirconium English powder, magnesia powder are sulfur absorbent, ferric oxide red powder is solidified rapidly cast(ing) surface, stops sulphur gas to enter iron liquid, and ferrosilicon powder prevents from solidifying rapidly generation cementite because of cast(ing) surface.Proportioning cost of the present invention is low, easy to prepare, in coating, by adding certain proportion to have after adsorbing material sulphur, sulphur can not be diffused in molten iron, prevents that flake graphite from appearring in cast(ing) surface, guarantees that mo(U)ld face nodularization is good.Coating prepared by the present invention has good wetability, has improved normal temperature, elevated temperature strength and the rigidity of coating, can corresponding minimizing casting defect.In castings production in enormous quantities, coating prepared by the present invention can improve casting yield, and low cost of manufacture, and manufacturing equipment is few, and each medium and small producer all can self manufacture.

The specific embodiment

Embodiment 1:

Resin sand is produced a spheroidal graphite cast-iron coating, following material, consists of, and is by weight percentage: zirconium English powder 45%, graphite powder 44%, sodium bentonite 3%, ferric oxide red powder 4%, ferrosilicon powder 2%, magnesia 1%, dextrin 1%.Its preparation method, comprises the following steps:

(1) 3 parts of sodium bentonites, 1 part of dextrin are stirred after adding appropriate alcohol, then add 45 parts of zirconium English powder, 44 parts of graphite powders, 4 parts of ferric oxide red powder, 2 parts of ferrosilicon powders, 1 part of magnesia, stir;

(2) with hairbrush, by the above-mentioned coating stirring, evenly brush is on resin-bonded sand cast form surface, and thickness is 0.3-0.5mm, then lights baking, on resin-bonded sand cast form surface, forms dope layer.

Embodiment 2:

Resin sand is produced a spheroidal graphite cast-iron coating, following material, consists of, and is by weight percentage: zirconium English powder 40%, graphite powder 47%, sodium bentonite 4%, ferric oxide red powder 3%, ferrosilicon 3%, magnesia 1.5%, dextrin 1.5%.Its preparation method, comprises the following steps:

(1) 4 parts of sodium bentonites, 1.5 parts of dextrin are stirred after adding appropriate alcohol, then add 40 parts of zirconium English powder, 47 parts of graphite powders, 3 parts of ferric oxide red powder, 3 parts of ferrosilicon powders, 1.5 parts of magnesia, stir;

(2) with hairbrush, by the above-mentioned coating stirring, evenly brush is on resin-bonded sand cast form surface, and thickness is 0.3-0.5mm, then lights baking, on resin-bonded sand cast form surface, forms dope layer.

Embodiment 3:

Resin sand is produced a spheroidal graphite cast-iron coating, following material, consists of, and is by weight percentage: zirconium English powder 48%, graphite powder 40%, sodium bentonite 3.5%, ferric oxide red powder 3%, ferrosilicon powder 2.5%, magnesia 2%, dextrin 1%.Its preparation method, comprises the following steps:

(1) 3.5 parts of sodium bentonites, 1 part of dextrin are stirred after adding appropriate alcohol, then add 48 parts of zirconium English powder, 40 parts of graphite powders, 3 parts of ferric oxide red powder, 2.5 parts of ferrosilicon powders, 2 parts of magnesia, stir;

(2) with hairbrush, by the above-mentioned coating stirring, evenly brush is on resin-bonded sand cast form surface, and thickness is 0.3-0.5mm, then lights baking, on resin-bonded sand cast form surface, forms dope layer.

Embodiment 4:

Resin sand is produced a spheroidal graphite cast-iron coating, following material, consists of, and is by weight percentage: zirconium English powder 43%, graphite powder 43%, sodium bentonite 3.8%, ferric oxide red powder 5%, ferrosilicon powder 2.5%, magnesia 1.5%, dextrin 1.2%.Its preparation method, comprises the following steps:

(1) 3.8 parts of sodium bentonites, 1.2 parts of dextrin are stirred after adding appropriate alcohol, then add 43 parts of zirconium English powder, 43 parts of graphite powders, 5 parts of ferric oxide red powder, 2.5 parts of ferrosilicon powders, 1.5 parts of magnesia, stir;

(2) with hairbrush, by the above-mentioned coating stirring, evenly brush is on resin-bonded sand cast form surface, and thickness is 0.3-0.5mm, then lights baking, on resin-bonded sand cast form surface, forms dope layer.

Claims (2)

1. resin sand is produced a spheroidal graphite cast-iron coating, it is characterized in that: following material, consist of, be by weight percentage: zirconium English powder 40-48%, graphite powder 40-48%, sodium bentonite 3-4%, ferric oxide red powder 3-5%, ferrosilicon powder 2-3%, magnesia 1-2%, dextrin 1-1.5%.

2. resin sand is produced a preparation method for spheroidal graphite cast-iron coating, it is characterized in that, comprises the following steps:

(1) 3-4 part sodium bentonite, 1-1.5 part dextrin are stirred after adding alcohol, then add 40-48 part zirconium English powder, 40-48 part graphite powder, 3-5 part ferric oxide red powder, 2-3 part ferrosilicon powder, 1-2 part magnesia, stir;

(2) with hairbrush, by the above-mentioned coating stirring, evenly brush is on resin-bonded sand cast form surface, and thickness is 0.3-0.5mm, then lights baking, on resin-bonded sand cast form surface, forms dope layer.