阅读说明：本技术 一种高强度高韧性铸态球墨铸铁及其制备方法 (A kind of high-intensity and high-tenacity cast condition ductile iron and preparation method thereof ) 是由 金昌林 马志 苟鸣 刘平 李红军 于 2019-09-27 设计创作，主要内容包括：本发明公开了一种高强度高韧性铸态球墨铸铁及其制备方法,化学成分的质量百分数为：C含量3.2-3.8%、Si含量2.4-2.8%、Mn含量0.4-0.7%、Cr含量<0.15%、P含量＜0.07%、S含量＜0.03%、Mg含量0.01～0.05%、Cu含量0.15-0.3%、剩余为铁元素及不可避杂质,通过熔炼、球化孕育、造型、冷却得到铸态球墨铸铁,利用合金元素调控基体组织、微量元素复合增韧技术,提高球墨铸铁件的综合力学能力,使其同时具有较高强度和高的延伸率,使其适用于批量生产。(The invention discloses a kind of high-intensity and high-tenacity cast condition ductile irons and preparation method thereof, the mass percent of chemical component are as follows: C content 3.2-3.8%, Si content 2.4-2.8%, Mn content 0.4-0.7%, Cr content < 0.15%, P content < 0.07%, S content < 0.03%, Mg content 0.01~0.05%, Cu content 0.15-0.3%, remaining as ferro element and impurity can not be kept away, pass through melting, spheroidization and inoculation, moulding, cooling obtains cast condition ductile iron, regulate and control matrix using alloying element, microelement composite toughening technology, improve the synthesis mechanics ability of nodular iron casting, make it while there is higher-strength and high elongation percentage, make it is suitable for batch production.)

1. a kind of high-intensity and high-tenacity cast condition ductile iron, which is characterized in that the mass percent of chemical component are as follows: C content 3.2-3.8%, Si content 2.4-2.8%, Mn content 0.4-0.7%, Cr content < 0.15%, P content < 0.07%, S content < 0.03%, Mg content 0.01~0.05%, Cu content 0.15-0.3%, remaining as ferro element and impurity can not be kept away.

2. high-intensity and high-tenacity cast condition ductile iron according to claim 1, it is characterised in that: the quality hundred of chemical component Score are as follows: C content 3.20-3.5%, Si content 2.5-2.8%, Mn content 0.40-0.70%, Cr content < 0.15%, P content < 0.07%, S content < 0.03%, Mg content 0.020~0.050%, Cu content 0.15-0.3%, remaining as ferro element and can not keep away miscellaneous Matter.

3. high-intensity and high-tenacity cast condition ductile iron according to claim 1, it is characterised in that: the cast condition ductile iron Nodulizing grade be 1-2 grades, 5-7 grades of sphere diameter size, content of pearlite in alloy is that content of pearlite in alloy is 50~65%.

4. high-intensity and high-tenacity cast condition ductile iron according to claim 1, it is characterised in that: the cast condition ductile iron Tensile strength be more than or equal to 600 megapascal, yield strength be more than or equal to 370 megapascal, elongation percentage be more than or equal to 10%, Bu Shi it is hard Degree is 190-250HBW.

5. a kind of preparation method of cast condition ductile iron, it is characterised in that: preparation is according to claim 1 to described in 4 any one High-intensity and high-tenacity cast condition ductile iron, this method operating procedure are as follows:

Step A, material is selected, and is selected carbon steel scrap, magnesium iron iron filings, spheroidal graphite cast-iron foundry returns as raw material, is matched carburant；

Step B, electric induction furnace melting is added in raw material by melting, and melting is to standing after 1520 degrees Celsius, after then being skimmed Obtain iron liquid；

Step C, spheroidization and inoculation will successively be added FeSiMg8Re2 nodulizer, ferrosilicon, silicon titanate innoculant, and cover in nodularization packet Iron liquid is poured and carries out nodularization in nodularization packet by perlite, to nodularization after slag making remove the gred, then carry out it is ladle-to-ladle breed, obtain Pure iron liquid；

Step D, the precoated sand prepared is added in type machine processed and carries out shell mould production by moulding, forms casting mold shell, the casting mold It is put into swage in shell, is then poured the casting-up position that the pure iron liquid after spheroidization and inoculation is hung to the swage, It is formed after casting complete to finished product；

Step E, cooling will be cooled down to finished product, and swage is carried out knockout of unpacking, obtains cast condition ductile iron.

6. the preparation method of cast condition ductile iron according to claim 5, it is characterised in that: the melting, to close At 1500 degrees Celsius, it is sampled analysis, adjusts ingredient based on the analysis results, time of repose is 3 to 5 minutes.

7. the preparation method of cast condition ductile iron according to claim 5, it is characterised in that: the spheroidization and inoculation is in nodularization Also enter red copper bits in packet, adds in the ladle-to-ladle preparation process with iron liquid addition SiBa composite inoculant, and after iron liquid is sufficiently stirred Coverture.

8. the preparation method of cast condition ductile iron according to claim 5, it is characterised in that: the moulding, in casting, Composite inoculant is added with stream and carries out current-following inoculation.

Technical field

The present invention relates to material preparations, and in particular to a kind of high-intensity and high-tenacity cast condition ductile iron and preparation method thereof.

Background technique

Cast iron is the iron-carbon alloy that phosphorus content is greater than 2.11%, is passed through by the steels such as commercial iron, steel scrap and its alloy material High-temperature fusion and casting and forming and obtain, in addition to Fe, also contain and other cast irons in carbon be precipitated with graphite form, if be precipitated stone Cast iron when ink is in strip of sheet is grey cast-iron or gray cast iron, in vermiform when cast iron vermicular cast iron, in group when cotton-shaped Cast iron of the cast iron malleable cast iron or code iron and when being in spherical is just spheroidal graphite cast-iron.Nodular iron casting is because having its good mechanics Performance and casting character are rapidly developed, it has also become a kind of selection for substituting the blank moulding material of cast steel, with economy The light-weighted demand of zero load of fast-developing and scientific and technological level raising, automobile product is constantly reinforced, and then has expedited the emergence of automobile zero Demand of the part to high-intensity and high-tenacity nodular iron casting.

For the demand for adapting to high-intensitive, high-tenacity nodular cast iron part, the research and development of such product material are opened in the market at present Begin to promote and apply, the performance boost research of existing spheroidal graphite cast-iron, mainly by obtaining high-intensity and high-tenacity ball after heat treatment Black cast iron lacks the process for stabilizing for meeting industrialized mass production at present, due to the use standard of existing malleable cast iron, allows to add Enter to obtain other alloying elements other than element required by regulation hardness and ingredient, therefore, is improved and cast by other alloying elements The intensity and toughness of state spheroidal graphite cast-iron are to be worth research.

Summary of the invention

The purpose of the present invention is to provide a kind of high-intensity and high-tenacity cast condition ductile irons and preparation method thereof, it is expected benefit Regulate and control matrix, microelement composite toughening technology with alloying element, improves the synthesis mechanics ability of nodular iron casting, make it There is higher-strength and high elongation percentage simultaneously.

In order to solve the above technical problems, the invention adopts the following technical scheme:

A kind of high-intensity and high-tenacity cast condition ductile iron, the mass percent of chemical component are as follows: C content 3.2-3.8%, Si content 2.4-2.8%, Mn content 0.4-0.7%, Cr content < 0.15%, P content < 0.07%, S content < 0.03%, Mg content 0.01~ 0.05%, Cu content 0.15-0.3%, remaining as ferro element and impurity can not be kept away.

Preferably, the mass percent of chemical component are as follows: C content 3.20-3.5%, Si content 2.5-2.8%, Mn content 0.40-0.70%, Cr content < 0.15%, P content < 0.07%, S content < 0.03%, Mg content 0.020~0.050%, Cu content 0.15-0.3%, remaining as ferro element and impurity can not be kept away.

Preferably, the nodulizing grade of above-mentioned cast condition ductile iron is 1-2 grades, 5-7 grades of sphere diameter size, content of pearlite in alloy is Content of pearlite in alloy is 50~65%.

Preferably, the tensile strength of above-mentioned cast condition ductile iron is more than or equal to 600 megapascal, yield strength is more than or equal to 370 megapascal, elongation percentage are more than or equal to 10%, Brinell hardness 190-250HBW.

The present invention also provides a kind of preparation methods of cast condition ductile iron, prepare the casting of high-intensity and high-tenacity as cast condition spheroidal graphite Iron, operating procedure are as follows: material is selected, and is selected carbon steel scrap, magnesium iron iron filings, spheroidal graphite cast-iron to melt down, is expected that, as raw material, apolegamy increases Carbon agent.

Electric induction furnace melting is added in raw material by melting, and melting is to standing after 1520 degrees Celsius, after then being skimmed To iron liquid.

Spheroidization and inoculation will successively be added FeSiMg8Re2 nodulizer, ferrosilicon, silicon titanate innoculant, and cover treasure in nodularization packet Iron liquid is poured and carries out nodularization in nodularization packet by Zhu Yan, to nodularization after slag making remove the gred, then carry out it is ladle-to-ladle breed, obtain pure Net iron liquid.

The precoated sand prepared is added in type machine processed and carries out shell mould production by moulding, forms casting mold shell, the casting mold type It is put into swage in shell, then the casting-up position that the pure iron liquid after spheroidization and inoculation is hung to the swage is poured, is poured It is formed after the completion of note to finished product.

It is cooling, it will be cooled down to finished product, and obtain cast condition ductile iron after moulding mould is removed in drawing operation.

Preferably, above-mentioned melting is sampled analysis, adjusts based on the analysis results when close to 1500 degrees Celsius Ingredient, time of repose are 3 to 5 minutes.

It is considered to be worth doing preferably, above-mentioned spheroidization and inoculation is additionally added red copper in nodularization packet, with iron liquid in above-mentioned ladle-to-ladle preparation process SiBa composite inoculant is added, and adds coverture after iron liquid is sufficiently stirred.

Preferably, above-mentioned moulding is added SiBa composite inoculant with stream and carries out current-following inoculation in casting.

Compared with prior art, beneficial effects of the present invention are at least one of following:

Cast condition ductile iron of the invention, basic material is very common, is easily obtained, and regulates and controls matrix using alloying elements such as Mn and Cu Tissue improves spheroidal graphite cast-iron comprehensive mechanical performance, and wherein Mn increases and refine pearlite, and Cu is medium promotion graphite element, Increase the influence of elongation percentage decline for offsetting Mn, so that stable austenite, improves the roundness of graphite and grade refines and stablizes Pearlite.

The preparation method of the present invention, using casting, to improve casting compactness, according to casting thickness and Shake-out Time The further homogenization and reduction casting stress of cooperation control cast structure, to improve the performance of casting.

Specific embodiment

In order to make the objectives, technical solutions, and advantages of the present invention clearer, with reference to embodiments, to the present invention It is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, it is not used to Limit the present invention.

One embodiment of the present of invention is a kind of high-intensity and high-tenacity cast condition ductile iron, the quality percentage of chemical component Number are as follows: the mass percent of chemical component are as follows: C content 3.2-3.8%, Si content 2.4-2.8%, Mn content 0.4-0.7%, Cr contains Amount < 0.15%, P content < 0.07%, S content < 0.03%, Mg content 0.01~0.05%, Cu content 0.15-0.3%, remaining as iron Element and impurity can not be kept away.

C content is 3.2-3.8%, and it is also most important element that wherein C, which is most basic in cast iron, and usual phosphorus content is analysed when high Graphite number out will increase, and wherein C content helps to be graphitized, and promote the absorption of Mg, and the graphite of spheroidal graphite cast-iron is in spherical, right Than with for gray cast iron, vermicular cast iron, code iron, influence of the spheroidal graphite to matrix and mechanical property is minimum, can sufficiently send out The effect for waving matrix assists nodularization effect generally for the mobility for improving iron liquid.

Si content is 2.4-2.8%, and Si, which belongs to, promotes graphited element, and the raising of Si content is conducive to improve the activity of C And its dissolution in iron liquid is reduced, and then promote graphitization, when Si is dissolved in matrix, solution strengthening can also be played Ferritic effect.

S content < 0.03%, S belong to carbide-forming element in spheroidal graphite cast-iron, but P content, which crosses conference, reduces iron liquid Mobility increases the cracked tendency of casting, therefore content should strict control.

Mn content be 0.4-0.7%, Mn can Mn increase and refinement pearlite, although Mn content increase can hinder to be graphitized Element causes elongation percentage to decline, but Mn can be solid-solution in ferrite and play solution strengthening ferrite.

Cu content 0.15-0.3%, Cu are medium promotion graphite elements, and Cu dissolves each other with iron liquid, form liquid solid solution, energy The combination for enough reducing carbon and iron has the function of strong promotion pearlite formation, reduces eutectoid, expand pearlite Limited proportionality promotes pearlite to form and refine pearlite, after Cu is combined with Mn, mutually promotes, stable austenite can be improved Roundness and the grade refinement of graphite and stable pearl hand over body, can also be reacted with sulphur by Mn, can also effectively reduce metal Remaining sulphur in liquid.

P content < 0.07%, P are also that common are harmful impurity element in spheroidal graphite cast-iron, but can drop to a certain extent The eutectic transformation temperature of low spheroidal graphite cast-iron, makes critical humidity range narrow, to improve the wearability of spheroidal graphite cast-iron；But P Content needs strict control, because the fusing point of P eutectic is lower, often exists in liquid form, and freezes solidly on eutectic cell boundary, if not Strict control P can reduce the mechanical property of spheroidal graphite cast-iron in content wherein.

Based on the above embodiment, compared to embodiment 1, its difference is the present embodiment, C content 3.20-3.5%, Si content 2.5-2.8%, since carbon equivalent generally takes near eutectic point, conducive to graphite expansion acting on from feeding to iron liquid, therefore, C content Selection additionally depend on casting section thickness, when belonging to thin-section casting, big or when breeding deficiency in nodularization element residual, C content is desirable Upper limit value；Conversely, removing limit value when belonging to thick-walled casting.It should be noted that casting is also easy to produce crackle, C when C content is too low Too high levels will appear graphite floatation, therefore the diminution C content of adaptability, stablizes it in 3.20-3.5%, can guarantee Under the premise of casting toughness, there is graphite floatation risk in reduction.

Wherein, the content of Si needs strict control, if Si too high levels easily lead to ferrite content increase, content of pearlite in alloy It reduces, and then leads to cast condition ductile iron strength reduction；When Si content is too low, under cast condition ductile iron plasticity exists significantly Drop, therefore, the diminution Si content of adaptability stablize it when for 2.5-2.8%, reduce cast condition ductile iron plasticity canyon wind Danger.

Based on the above embodiment, the present invention also provides a kind of preparation methods of cast condition ductile iron, high-intensitive high with preparation Toughness cast condition ductile iron, operating procedure are as follows: material is selected, and carbon steel scrap, magnesium iron iron filings, spheroidal graphite cast-iron is selected to melt down, expect As raw material, carburant is matched；Wherein, carburant refers to that carbon product makes its molecular structure by high temperature or other modes Change, well-regulated arrangement, this molecules align mode, the intermolecular distance of carbon is wider, divides more conducively in iron liquid or molten steel Solve forming core, the carburant that the application uses can be graphite electrode waste material cutting or 3000 degree of petroleum coke of graphitization product, Steel scrap dosage is increased considerably by carburant, reduces pig iron dosage, using pure carbon containing graphitization substance itself is selected, is dropped Excessive impurity in the low pig iron can reduce castings production cost by carburant.

Electric induction furnace melting is added in raw material by melting, and melting is to standing after 1520 degrees Celsius, after then being skimmed To iron liquid.Wherein, smelting temperature directly decides the air content and alloying element content of iron liquid, and then influences the pure of iron liquid Degree, when temperature is more than close to 1500 degrees Celsius, the oxygen content in iron liquid is remarkably decreased, therefore after 1520 degrees Celsius, unsuitable Continue to increase.

Spheroidization and inoculation will successively be added FeSiMg8Re2 nodulizer, ferrosilicon, silicon titanate innoculant, and cover treasure in nodularization packet Iron liquid is poured and carries out nodularization in nodularization packet by Zhu Yan, to nodularization after slag making remove the gred, then carry out it is ladle-to-ladle breed, obtain pure Net iron liquid.Wherein, ferrosilicon contains the substances such as calcium, aluminium, because the pregnant effect of silicon is low, need to arrange in pairs or groups calcium, aluminium etc. are beneficial to mention The substance of high pregnant effect.Wherein, silicon titanate innoculant, the alloy based on mainly siliceous barium element are extremely strong using barium element Nucleation ability largely improves Eutectic Cell Number, promotes the anti-ageing ability of moving back of iron liquid.

The precoated sand prepared is added in type machine processed and carries out shell mould production by moulding, forms casting mold shell, the casting mold type It is put into swage in shell, then the casting-up position that the pure iron liquid after spheroidization and inoculation is hung to the swage is poured, is poured It is formed after the completion of note to finished product；Shell mould is made by using precoated sand, puts it into casting in molding metal mold, realization is being cast Steady production is industrialized under the conditions of state, guarantees the uniformity bred by way of current-following inoculation, and easy to operate.

It is cooling, it will be cooled down to finished product, swage is subjected to knockout of unpacking, obtains cast condition ductile iron.

Further, above-mentioned melting is sampled analysis, adjusts based on the analysis results when close to 1500 degrees Celsius Ingredient, time of repose are 3 to 5 minutes, since carbon-based incoculant has extremely strong graphitization and the anti-ageing ability of moving back, since it is molten Point is very high therefore high to inoculation temperature requirement, it is therefore desirable at 1500 degrees Celsius, be detected, in order to guarantee to breed Effect.

Further, above-mentioned spheroidization and inoculation is additionally added red copper in nodularization packet and considers to be worth doing, with iron liquid in above-mentioned ladle-to-ladle preparation process SiBa composite inoculant is added, and adds coverture after iron liquid is sufficiently stirred, is used as Cu content by red copper bits, SiBa is compound pregnant Agent is educated, to dramatically increase number of graphite ball, homogeneity of fault plane is improved, improves the intensity of cast condition ductile iron.

Further, above-mentioned moulding is added SiBa composite inoculant with stream and carries out current-following inoculation, SiBa is multiple in casting Inovulant is closed to be conducive to graphitization and anti-ageing move back；It should be noted that pouring temperature is also for the casting of different wall thickness Difference, for thin-wall part, pouring temperature is unsuitable excessively high, and the shrinkage that otherwise will lead to iron liquid increases, and generates shrinkage porosite, shrinkage cavity etc. Defect, temperature is usually in 1300 degrees centigrades, for thick-walled casting, if pouring temperature is excessively high, exist generate graphite floatation, The risk of decaying spheroidisation.

The present embodiment is to examine embodiment, is provided according to the size of the nodular iron casting tensile sample of GB/T1348-2009, Product is detected, measures tensile test Rmin >=600MPa, Rsmin >=370MPa, elongation percentage A >=10%, hardness HB is 190~250, main chemical composition analysis is carried out to metallographic specimen using spectroanalysis instrument, utilizes type optical microscopy, scanning Electron microscope observes graphite form, matrix pattern, the synusia spacing of pearlite, primary austenite pattern etc., 1~2 grade of its nodulizing grade, 5~7 grades of sphere diameter size, content of pearlite in alloy is 50~65%, since the mode of comparison metallograph is surveyed Calculating Oxygen potential, there is a certain error, therefore can also be according in the GB/T9441-2009 with more scientific and practicability Counting method calculates Oxygen potential.

" one embodiment ", " another embodiment ", " embodiment ", " preferred implementation spoken of in the present specification Example " etc., referring to combining specific features, structure or the feature of embodiment description includes describing extremely in the application generality In few one embodiment.It is not centainly to refer to the same embodiment that statement of the same race, which occur, in multiple places in the description.Into one For step, when describing a specific features, structure or feature in conjunction with any embodiment, what is advocated is to combine other implementations Example realizes that this feature, structure or feature are also fallen within the scope of the present invention.

Although reference be made herein to invention has been described for multiple explanatory embodiments of the invention, however, it is to be understood that Those skilled in the art can be designed that a lot of other modification and implementations, these modifications and implementations will fall in this Shen It please be within disclosed scope and spirit.It more specifically, within the scope of the present disclosure and claims, can be to master The building block and/or layout for inscribing composite configuration carry out a variety of variations and modifications.In addition to what is carried out to building block and/or layout Outside modification and improvement, to those skilled in the art, other purposes also be will be apparent.