CN111074034A - Preparation method of as-cast mixed matrix QT600-10 nodular cast iron - Google Patents
Preparation method of as-cast mixed matrix QT600-10 nodular cast iron Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/10—Making spheroidal graphite cast-iron
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/08—Making cast-iron alloys
- C22C33/10—Making cast-iron alloys including procedures for adding magnesium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C37/00—Cast-iron alloys
- C22C37/04—Cast-iron alloys containing spheroidal graphite
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C37/00—Cast-iron alloys
- C22C37/10—Cast-iron alloys containing aluminium or silicon
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Abstract
The invention provides a preparation method of as-cast mixed matrix QT600-10 nodular cast iron, which comprises the following steps: s1, the raw materials are added in percentage by mass as follows: pig iron: 40-60%, scrap steel: 25-40%, foundry returns: 10-20%, electrolytic copper plate: 0.1-0.3%; s2, smelting molten iron: adding an electrolytic copper plate after scrap steel, pig iron and foundry returns are completely melted; s3, melt treatment in the bag: putting a rare earth-containing nodulizer on one side of the bottommost part of a nodulizing ladle, putting a silicon-barium-calcium inoculant on the upper part of metal particles containing the rare earth nodulizer, discharging molten iron from a furnace, flushing the molten iron into the nodulizing ladle, and performing nodulizing and ladle inoculation, wherein the nodulizing treatment temperature is 1500-1550 ℃; s4, pouring: and transferring the molten iron in the spheroidizing ladle to a pouring site for pouring, wherein the pouring temperature of the molten iron is 1380-1420 ℃, and a strontium-silicon stream inoculant is added along with the molten iron during pouring. The invention regulates and controls the content range of pearlite and ferrite in the matrix structure through the selection and control of raw materials and the design of alloy components, thereby obtaining the nodular cast iron material which is used for elevator components.
Description
Technical Field
The invention belongs to the field of high-performance metal materials, and particularly relates to a preparation method of as-cast mixed matrix QT600-10 nodular cast iron.
Background
With the development of casting technology, the production technology and application of high-performance nodular cast iron materials make remarkable progress, and particularly, the production cost can be effectively reduced by obtaining high strength and high elongation in an as-cast state, so that the method is widely concerned by many enterprises and cast material researchers. As for elevator parts, the nodular cast iron has high strength and high elongation, so that the overall safety coefficient and the fatigue service life of the product can be improved, the structure of the product can be further optimized, and the wall thickness of the product is reduced to obtain a weight reduction effect; the steel can be used for replacing part of steel materials, so that the casting defect of steel castings is eliminated, and the light weight work of elevator components is promoted.
The mechanical property of the high-performance QT600-10 nodular cast iron material requires that the tensile strength is more than or equal to 600MPa, the elongation is more than or equal to 10 percent, the mechanical property mainly depends on the metallographic structure of the high-performance QT600-10 nodular cast iron material, the metallographic structure mainly comprises a metal matrix and graphite, and the proportion of the graphite to the matrix structure is strictly regulated and controlled if the high-strength high-toughness QT600-10 nodular cast iron material with stable performance is obtained. The method disclosed in the Chinese invention patent CN102230122A 'a production method of nodular cast iron', and the Chinese invention patent CN103981434A 'a production method of high-toughness nodular cast iron', can not stably realize that the as-cast elongation is more than or equal to 10% in actual production; the matrix tissues of the nodular cast iron prepared in the Chinese invention patent CN103710612A 'production method of as-cast ferrite-based nodular cast iron QT 600-10' are ferrite tissues, so that the as-cast tensile strength of the nodular cast iron cannot be stably maintained to be more than or equal to 600 MPa; in the Chinese invention patent CN106868395A 'production method of mixed matrix structure as-cast nodular cast iron', Ca and Ba microelements are added into alloy components, the melt processing flow is long, the operation is complicated, and the matrix graphite structure is unstable.
Disclosure of Invention
In view of the defects, the invention aims to provide a preparation method of as-cast mixed matrix QT600-10 nodular cast iron, so that high-strength and high-toughness nodular cast iron with stable performance is obtained.
The invention provides a preparation method of as-cast mixed matrix QT600-10 nodular cast iron, which comprises the following steps:
s1, the raw materials are added in percentage by mass as follows: pig iron: 40-60%, scrap steel: 25-40%, foundry returns: 10-20%, electrolytic copper plate: 0.1-0.3%;
s2, smelting molten iron: adding scrap steel, pig iron and foundry returns, adding an electrolytic copper plate after the scrap steel, the pig iron and the foundry returns are completely melted, controlling the temperature in the melting process at 1350-1390 ℃, and controlling the tapping temperature of a melt at 1510-1550 ℃;
s3, melt treatment in the bag: putting a rare earth-containing nodulizer on one side of the bottommost part of a nodulizing ladle, putting a silicon-barium-calcium inoculant on the upper part of metal particles containing the rare earth-containing nodulizer, discharging molten iron from a furnace, flushing the molten iron into the nodulizing ladle, and performing nodulizing and ladle inoculation, wherein the nodulizing treatment temperature is 1500-1550 ℃;
s4, pouring: and transferring the molten iron in the spheroidizing ladle to a pouring site for pouring, wherein the pouring temperature of the molten iron is 1380-1420 ℃, and a strontium-silicon stream inoculant is added along with the molten iron during pouring.
Preferably, in step S1, the pig iron comprises the following components in percentage by mass: c is more than 4 percent, Si is less than 0.5 percent, Mn is less than 0.05 percent, P is less than 0.02 percent, S is less than 0.02 percent, Ti is less than 0.02 percent, and the scrap steel comprises the following components in percentage by mass: less than 0.04 percent of C, less than 0.007 percent of Si, less than 0.2 percent of Mn, less than 0.008 percent of P, less than 0.006 percent of S and less than 0.001 percent of Ti.
Preferably, in step S3, the silicon barium calcium inoculant has a particle size of 3-10 mm, and comprises the following components in percentage by mass: ca: 2.0-2.5%, Si: 70-75%, Al: 1-1.5%, Ba: 5-6%, Mn: 0.1 to 0.15 percent.
Preferably, in step S3, the spheroidizing bag is a dam-type bag, and the spheroidizing agent is a low-magnesium low-rare earth spheroidizing agent with a particle size of 10-30 mm.
Preferably, the low-magnesium low-rare earth nodulizer comprises the following components in percentage by mass: re: 0.8-1.2%, Mg: 6.5-7.5%, Si: 35-45%, Al: 0.4-0.6%, Mn: 0.1-0.2%, Ca: proper amount.
Preferably, in step S3, after the spheroidization reaction is finished, sampling and detecting to control that the spheroidized molten iron includes the following components by mass percent: c: 3.2-3.5%, Si: 3.7-4.0%, Mn < 0.2%, Cu: 0.1-0.3%, P < 0.02%, S < 0.02%, Mg: 0.06-0.09%, Re: 0.01-0.02%, and the balance of Fe and impurities.
Preferably, in step S4, the grain size of the strontium silicon stream inoculant is 0.2-0.8 mm.
Preferably, the method further comprises the following steps:
s5, filtering: filtering the molten iron by adopting a foamed ceramic filter;
s6, sand mold heat preservation: keeping the temperature for 48 hours, then shakeout and unpacking;
preferably, in the step S5, the material of the ceramic foam filter is ZrO2, SiC, Al2O3 or a mixture of ZrO2, SiC and Al2O3, and the pore size of the ceramic foam filter is 5 to 30ppi, and the size is Φ 80mm × 30 mm.
Preferably, in the step S5, the ceramic foam filter is placed on both sides of the runner.
The invention has the following beneficial effects:
1. selecting raw materials: the invention adopts high-quality low-manganese carbon scrap steel and high-purity pig iron as main raw materials, and avoids introducing other interference elements into the raw materials to finally influence the comprehensive performance of the as-cast mixed matrix QT600-10 nodular cast iron material.
2. Controlling alloy elements: in order to ensure that ferrite with sufficient content is contained and fully utilize the solid solution strengthening effect of Si element, compared with other high-silicon solid solution strengthening methods, the method disclosed by the invention reserves the pearlite matrix strengthening to reduce the required Si addition, and further ensures that the ferrite matrix has certain ductility and toughness, so that the mass percentage of Si in the method is controlled to be 3.7-4.0%. In addition, in order to ensure good spheroidizing effect, improve the magnesium absorption rate and improve the fluidity, the carbon content is controlled to be 3.2-3.5%.
3. Selection and control of trace alloy elements: both Cu and Mn have a solid solution strengthening effect on ferrite, and can stabilize and refine pearlite. Cu is completely dissolved in the matrix in a solid solution, but the effect of promoting the formation of pearlite is too strong, so that the elongation after fracture is influenced, and therefore, the mass percent of Cu is controlled to be 0.1-0.3%. Mn has obvious effect on improving the strength of the matrix, but the increase of Mn content can form carbide and white layer in the matrix, weaken the mechanical property of the nodular cast iron and rapidly reduce the elongation, so the invention controls the mass percent of the Mn to be not more than 0.3 percent, and generally to be not more than 0.2 percent. The content range of pearlite in the matrix structure is controlled to be 15-35% by adding the trace elements, so that the strength requirement of the nodular cast iron material can be met, and the plasticity and toughness are not lost.
Drawings
FIG. 1 is a metallographic photograph of a matrix structure of an example;
FIG. 2 is a metallographic photograph of a matrix structure of comparative example 1;
FIG. 3 is a metallographic photograph of a matrix structure of comparative example 2;
FIG. 4 is a metallographic photograph of a matrix structure of comparative example 3.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be understood that the processing equipment or apparatus not specifically identified in the following examples is conventional in the art. Furthermore, it is to be understood that one or more method steps mentioned in the present invention does not exclude that other method steps may also be present before or after the combined steps or that other method steps may also be inserted between these explicitly mentioned steps, unless otherwise indicated; it is also to be understood that a combined connection between one or more devices/apparatus as referred to in the present application does not exclude that further devices/apparatus may be present before or after the combined device/apparatus or that further devices/apparatus may be interposed between two devices/apparatus explicitly referred to, unless otherwise indicated. Moreover, unless otherwise indicated, the numbering of the various method steps is merely a convenient tool for identifying the various method steps, and is not intended to limit the order in which the method steps are arranged or the scope of the invention in which the invention may be practiced, and changes or modifications in the relative relationship may be made without substantially changing the technical content.
Examples
The invention provides a preparation method of as-cast mixed matrix QT600-10 nodular cast iron, which comprises the following steps:
s1, the raw materials are added in percentage by mass as follows: pig iron: 40-60%, scrap steel: 25-40%, foundry returns: 10-20%, electrolytic copper plate: 0.1 to 0.3 percent. Specifically, the pig iron is high-purity pig iron and comprises the following components in percentage by mass: c is more than 4 percent, Si is less than 0.5 percent, Mn is less than 0.05 percent, P is less than 0.02 percent, S is less than 0.02 percent, Ti is less than 0.02 percent, and the used scrap steel is scrap steel with low manganese content and comprises the following components in percentage by mass: less than 0.04 percent of C, less than 0.007 percent of Si, less than 0.2 percent of Mn, less than 0.008 percent of P, less than 0.006 percent of S and less than 0.001 percent of Ti. Both pig iron and scrap steel need to be subjected to shot blasting treatment to treat surface rust and other impurities before use.
S2, smelting molten iron: adding scrap steel, pig iron and foundry returns, adding an electrolytic copper plate after the scrap steel, the pig iron and the foundry returns are completely melted, controlling the temperature in the melting process to be 1350-1390 ℃, and controlling the tapping temperature of the melt to be 1510-1550 ℃.
S3, melt treatment in the bag: and (3) cleaning the slag on the surface of the molten iron, then flushing all the discharged molten iron into a spheroidizing ladle, and carrying out spheroidizing and ladle inoculation. 0.8-1.5% by mass of low-magnesium low-rare earth nodulizer metal particles are put into one side of the bottommost part of the nodulizing ladle, and the low-magnesium low-rare earth nodulizer comprises the following components in percentage by mass: re: 0.8-1.2%, Mg: 6.5-7.5%, Si: 35-45%, Al: 0.4-0.6%, Mn: 0.1-0.2%, Ca: proper amount, and the granularity is 10-30 mm. Uniformly covering the nodulizer with 0.4-0.7% of silicon-barium-calcium long-acting inoculant by mass percent, pounding the particles in the nodulizing packet to be solid, and then covering the particles with a ductile iron sheet. Wherein, the mass percentages of the low-magnesium low-rare earth nodulizer and the silicon barium calcium inoculant are relative to the total mass of the molten iron in the nodulizing ladle. The silicon-barium-calcium long-acting inoculant comprises the following components in percentage by mass: ca: 2.0-2.5%, Si: 70-75%, Al: 1-1.5%, Ba: 5-6%, Mn: 0.1-0.15% and a particle size of 3-10 mm.
The spheroidizing bag is specifically processed by adopting a dam type, the spheroidizing reaction time is controlled to be 30-40 seconds, and the spheroidizing temperature is 1500-1530 ℃. After the spheroidization reaction is finished, sampling and detecting, and controlling the components of molten iron after spheroidization: c: 3.2-3.5%, Si: 3.7-4.0%, Mn < 0.2%, P < 0.02%, S < 0.02%, Mg: 0.06-0.09%, Cu: 0.1 to 0.3%, Re: 0.01 to 0.02% and the balance of Fe and inevitable impurities. And after the reaction is finished, spreading a slag removing agent on the molten iron in the spheroidizing bag to remove slag quickly, and completely removing the molten slag on the surface of the molten iron.
S4, pouring: and transferring the molten iron in the spheroidizing ladle to a pouring site for pouring, wherein the pouring temperature of the molten iron is 1380-1420 ℃, and a strontium silicon inoculant with the mass percent of 0.05-0.15 percent is added above a pouring cup along with the molten iron during pouring, and the granularity of the strontium silicon inoculant is 0.2-0.8 mm. And controlling the time within 8min from the end of spheroidization to the end of casting.
S5, filtering: filtering and purifying the molten iron by adopting a ceramic foam filter, wherein the ceramic foam filter is made of ZrO2、SiC、Al2O3Or from ZrO2SiC and Al2O3Mixed composition of ZrO in the mixed composition2SiC and Al2O3The mass percentage content of the organic silicon compound is 80-65%, 10-25% and 10-25% in sequence. The pore diameter of the foamed ceramic filter is 5-30 ppi, specifically 10ppi is adopted, and the size is phi 80mm multiplied by 30 mm. The ceramic foam filter is placed on both sides of the runner.
S6, sand mold heat preservation: and (5) performing heat preservation for 48 hours, then shakeout and unpacking.
Between the steps S5 and S6, the method further comprises the step of single casting a Y-shaped test block, wherein the size of the Y-shaped test block is performed according to the GB/T1348-2009 nodular iron casting. And (3) dissecting the single-cast Y-shaped test block, processing the core part of the single-cast Y-shaped test block into a tensile test bar, a metallographic sample and a component analysis sample, and inspecting chemical components, metallographic structures and mechanical properties.
The chemical analysis results of the prepared single-cast test block are shown in table 1, the as-cast metallographic structure inspection results are shown in table 2, the spheroidization grade of the nodular cast iron prepared in the embodiment is grade 1, the size of graphite nodules is grade 6, the spheroidization rate is more than 95%, the matrix structure is 20-35% of pearlite, and the ferrite is 60-85%. The performance test of the as-cast mixed matrix QT600-10 nodular cast iron prepared in the embodiment is shown in Table 3, and the test result shows that the mechanical property of the single-cast test block in the embodiment reaches Rm≥600MPa、Rp0.2Not less than 450MPa, A not less than 15%, and various performances meeting design requirements.
Comparative example 1
Comparative example 1 relates to an as-cast mixed matrix QT600-10 nodular cast iron and a method for its preparation, which differs from the examples in that: comparative example 1 the mass percentage of Si in the molten iron composition after spheroidizing was controlled to 4.0 to 4.3%. After the spheroidization reaction is finished, sampling and detecting are carried out, and the components of molten iron after spheroidization are controlled: c: 3.2-3.5%, Si: 4.0-4.3%, Mn less than 0.2%, P less than 0.02%, S less than 0.02%, Mg: 0.06-0.09%, Cu: 0.1 to 0.3%, Re: 0.01 to 0.02% and the balance of Fe and inevitable impurities.
The chemical analysis results of the prepared single cast test block are shown in Table 1, the cast metallographic structure examination is shown in Table 2, the spheroidization grade is grade 1, the size of graphite nodules is grade 6,the spheroidization rate is more than 95 percent, and the ferrite matrix structure is more than 90 percent. The performance test of the as-cast mixed matrix QT600-10 nodular cast iron prepared by the comparative example is shown in Table 3, and the test result shows that when the mass percent of the silicon element is increased to be within the range of 4.0-4.3%, the tensile strength of the material is remarkably reduced, and the tensile strength and the elongation of the material cannot be stably maintained at RmNot less than 600MPa and A not less than 15%.
Comparative example 2
Comparative example 2 relates to an as-cast mixed matrix QT600-10 nodular cast iron and a method for its preparation, which differs from the examples in that: comparative example 2 the mass percentage of Mn in the spheroidized iron liquid component was controlled to 0.4 to 0.6%. Meanwhile, in order to ensure that the carbon equivalent of the alloy material can be controlled to be about 4.3 percent, the mass percentage of Si in the alloy elements is properly reduced to 3.4-3.6 percent. After the spheroidization reaction is finished, sampling and detecting are carried out, and the components of molten iron after spheroidization are controlled: c: 3.2-3.5%, Si: 3.4-3.6%, Mn: 0.4-0.6%, P less than 0.02%, S less than 0.02%, Mg: 0.06-0.09%, Cu: 0.1 to 0.3%, Re: 0.01 to 0.02% and the balance of Fe and inevitable impurities.
The chemical analysis results of the prepared single cast test block are shown in table 1, the cast metallographic structure is tested and shown in table 2, the spheroidization grade is grade 1, the size of graphite nodules is grade 6, the spheroidization rate is more than 95%, the matrix structure is pearlite 40-50%, and ferrite 40-60%. The property test of the as-cast mixed matrix QT600-10 nodular cast iron prepared by the invention is shown in Table 3, and the test result shows that when the content of Mn element is increased to 0.5%, compared with the embodiment and the comparative example 1, the tensile strength and the yield strength of the nodular cast iron material prepared by the comparative example are remarkably increased, but the elongation is greatly reduced compared with the embodiment and the comparative example 1. By increasing the content of Mn element, the pearlite content in the matrix structure is increased, the ferrite content is reduced, and although the tensile strength meets the design requirement, the elongation rate cannot be stably maintained to be more than or equal to 10%.
Comparative example 3
Comparative example 3 relates to an as-cast mixed matrix QT600-10 nodular cast iron and a method for its preparation, which differs from the examples in that: comparative example 3 the mass percent of Cu in the spheroidized iron liquid component was controlled to 0.3 to 0.5%, which is helpful for increasing the pearlite content in the matrix structure. Meanwhile, in order to ensure that the carbon equivalent of the alloy material can be controlled to be about 4.3 percent, the mass percent of Si in the alloy elements is properly reduced to 2.4-2.6 percent, the solid solution strengthening effect can be reduced, and the ferrite content in the matrix structure can be reduced. The mass percent of Mn is controlled to be 0.4-0.6%. After the spheroidization reaction is finished, sampling and detecting are carried out, and the components of molten iron after spheroidization are controlled: c: 3.2-3.5%, Si: 2.4-2.6%, Mn: 0.4-0.6%, P less than 0.02%, S less than 0.02%, Mg: 0.06-0.09%, Cu: 0.3-0.5%, Re: 0.01 to 0.02% and the balance of Fe and inevitable impurities.
The chemical analysis result of the prepared single-cast test block is shown in table 1, the cast metallographic structure is tested and shown in table 2, the spheroidization grade is grade 1, the size of graphite nodules is grade 6, the spheroidization rate is more than 95%, the matrix structure is ferrite 10-20%, and pearlite 70-90%. The performance test of the as-cast mixed matrix QT600-10 nodular cast iron prepared by the comparative example is shown in Table 3, and the test result shows that compared with the examples, the comparative example 1 and the comparative example 2, the tensile strength of the nodular cast iron material prepared by the comparative example is far higher than 600MPa, but the elongation is only 5%. The pearlite content in the matrix structure is improved by improving the contents of Cu and Mn elements, the ferrite content is reduced, and the overall performance cannot meet the design requirement.
TABLE 1
| Chemical composition | C | Si | Mn | Cu | P | S | Mg | Re |
| Examples | 3.43 | 3.89 | 0.195 | 0.280 | 0.0154 | 0.0086 | 0.0779 | 0.012 |
| Comparative example 1 | 3.28 | 4.25 | 0.0256 | 0.100 | 0.0174 | 0.0103 | 0.0830 | 0.013 |
| Comparative example 2 | 3.48 | 3.41 | 0.551 | 0.255 | 0.0177 | 0.006 | 0.0630 | 0.014 |
| Comparative example 3 | 3.49 | 2.48 | 0.731 | 0.328 | 0.0192 | 0.0086 | 0.0729 | 3.49 |
TABLE 2
TABLE 3
The invention designs the alloy components through the selection and control of raw materials; the content ranges of pearlite and ferrite in a matrix tissue are regulated and controlled by selecting a proper inoculant, a nodulizer, a stream inoculant and a foamed ceramic filter and assisting corresponding melt inoculation and nodulizing treatment processes, so that the nodular cast iron material for elevator parts is obtained. The as-cast mixed matrix QT600-10 nodular cast iron material obtained by implementing the preparation method of the nodular cast iron has the mechanical property Rm of a single cast test block of more than or equal to 600MPa and Rp0.2More than or equal to 450MPa, more than or equal to 15 percent of A, 20 to 35 percent of pearlite content, 60 to 85 percent of ferrite content, grade 1 to grade 2 of spheroidization, 6 to 7 grades of graphite nodule size and more than 95 percent of graphite nodule spheroidization rate.
Compared with the prior art, the invention has the following beneficial effects:
1. selecting raw materials: the invention adopts high-quality low-manganese carbon scrap steel and high-purity pig iron as main raw materials, and avoids introducing other interference elements into the raw materials to finally influence the comprehensive performance of the as-cast mixed matrix QT600-10 nodular cast iron material.
2. Controlling alloy elements: in order to ensure that ferrite with sufficient content is contained and fully utilize the solid solution strengthening effect of Si element, compared with other high-silicon solid solution strengthening methods, the method disclosed by the invention reserves the pearlite matrix strengthening to reduce the required Si addition, and further ensures that the ferrite matrix has certain ductility and toughness, so that the mass percentage of Si in the method is controlled to be 3.7-4.0%. In addition, in order to ensure good spheroidizing effect, improve the magnesium absorption rate and improve the fluidity, the carbon content is controlled to be 3.2-3.5%.
3. Selection and control of trace alloy elements: both Cu and Mn have a solid solution strengthening effect on ferrite, and can stabilize and refine pearlite. Cu is completely dissolved in the matrix in a solid solution, but the effect of promoting the formation of pearlite is too strong, so that the elongation after fracture is influenced, and therefore, the mass percent of Cu is controlled to be 0.1-0.3%. Mn has obvious effect on improving the strength of the matrix, but the increase of Mn content can form carbide and white layer in the matrix, weaken the mechanical property of the nodular cast iron and rapidly reduce the elongation, so the invention controls the mass percent of the Mn to be not more than 0.3 percent, and generally to be not more than 0.2 percent. The content range of pearlite in the matrix structure is controlled to be 15-35% by adding the trace elements, so that the strength requirement of the nodular cast iron material can be met, and the plasticity and toughness are not lost.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.
Claims (10)
1. A preparation method of as-cast mixed matrix QT600-10 nodular cast iron is characterized by comprising the following steps:
s1, the raw materials are added in percentage by mass as follows: pig iron: 40-60%, scrap steel: 25-40%, foundry returns: 10-20%, electrolytic copper plate: 0.1-0.3%;
s2, smelting molten iron: adding scrap steel, pig iron and foundry returns, adding an electrolytic copper plate after the scrap steel, the pig iron and the foundry returns are completely melted, controlling the temperature in the melting process at 1350-1390 ℃, and controlling the tapping temperature of a melt at 1510-1550 ℃;
s3, melt treatment in the bag: putting a rare earth-containing nodulizer on one side of the bottommost part of a nodulizing ladle, putting a silicon-barium-calcium inoculant on the upper part of metal particles containing the rare earth-containing nodulizer, discharging molten iron from a furnace, flushing the molten iron into the nodulizing ladle, and performing nodulizing and ladle inoculation, wherein the nodulizing treatment temperature is 1500-1550 ℃;
s4, pouring: and transferring the molten iron in the spheroidizing ladle to a pouring site for pouring, wherein the pouring temperature of the molten iron is 1380-1420 ℃, and a strontium-silicon stream inoculant is added along with the molten iron during pouring.
2. The method for producing spheroidal graphite cast iron according to claim 1, wherein in step S1, the pig iron includes the following components by mass percent: c is more than 4 percent, Si is less than 0.5 percent, Mn is less than 0.05 percent, P is less than 0.02 percent, S is less than 0.02 percent, Ti is less than 0.02 percent, and the scrap steel comprises the following components in percentage by mass: less than 0.04 percent of C, less than 0.007 percent of Si, less than 0.2 percent of Mn, less than 0.008 percent of P, less than 0.006 percent of S and less than 0.001 percent of Ti.
3. The preparation method of nodular cast iron according to claim 1, wherein in step S3, the silicon barium calcium inoculant has a particle size of 3-10 mm and comprises the following components in percentage by mass: ca: 2.0-2.5%, Si: 70-75%, Al: 1-1.5%, Ba: 5-6%, Mn: 0.1 to 0.15 percent.
4. The method according to claim 1, wherein in step S3, the spheroidizing ladle is a dam-type ladle, and the spheroidizing agent is a low-magnesium low-rare earth spheroidizing agent with a particle size of 10-30 mm.
5. The method for preparing ductile iron according to claim 4, wherein the low-magnesium low-rare earth nodulizer comprises the following components in percentage by mass: re: 0.8-1.2%, Mg: 6.5-7.5%, Si: 35-45%, Al: 0.4-0.6%, Mn: 0.1-0.2%, Ca: proper amount.
6. The method according to claim 1, wherein in step S3, after the spheroidization reaction is completed, sampling and detecting are performed, and the molten iron after spheroidization is controlled to include the following components in percentage by mass: c: 3.2-3.5%, Si: 3.7-4.0%, Mn < 0.2%, Cu: 0.1-0.3%, P < 0.02%, S < 0.02%, Mg: 0.06-0.09%, Re: 0.01-0.02%, and the balance of Fe and impurities.
7. The method for preparing spheroidal graphite cast iron according to claim 1, wherein in step S4, the grain size of the strontium silicon stream inoculant is 0.2-0.8 mm.
8. The method of preparing ductile iron according to claim 1, further comprising the steps of:
s5, filtering: filtering the molten iron by adopting a foamed ceramic filter;
s6, sand mold heat preservation: and (5) performing heat preservation for 48 hours, then shakeout and unpacking.
9. The method according to claim 8, wherein in step S5, the ceramic foam filter is ZrO2、SiC、Al2O3Or from ZrO2SiC and Al2O3And mixing, wherein the pore diameter of the foamed ceramic filter is 5-30 ppi, and the size is phi 80mm multiplied by 30 mm.
10. The method according to claim 8, wherein in step S5, the ceramic foam filters are placed on both sides of the runner.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111961954A (en) * | 2020-08-26 | 2020-11-20 | 上海烟草机械有限责任公司 | Preparation method of as-cast mixed matrix QT500-14 nodular cast iron |
| CN112176243A (en) * | 2020-10-30 | 2021-01-05 | 山东省源通机械股份有限公司 | Nodular cast iron material for producing explosion-proof motor casting and preparation method thereof |
| CN112662937A (en) * | 2020-12-07 | 2021-04-16 | 安徽省隆兴铸造有限公司 | High-tensile-strength nodular cast iron and valve preparation method thereof |
| CN112962018A (en) * | 2021-01-29 | 2021-06-15 | 宁波日星铸业有限公司 | Chilling process manufacturing method of non-label QT600-7 nodular cast iron |
| CN115595496A (en) * | 2022-10-20 | 2023-01-13 | 无锡烨隆精密机械股份有限公司（Cn） | QT600 nodular cast iron and preparation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013117045A (en) * | 2011-12-02 | 2013-06-13 | Akebono Brake Ind Co Ltd | Thin-walled spheroidal graphite cast iron member |
| CN104975127A (en) * | 2015-06-27 | 2015-10-14 | 芜湖市容川机电科技有限公司 | Auxiliary material used for production of nodular cast iron QT600-10 |
| CN105861917A (en) * | 2016-04-14 | 2016-08-17 | 东风精密铸造有限公司 | Production method for as-cast high-performance ductile iron QT600-10 by precision-investment casting |
| CN107779737A (en) * | 2017-10-24 | 2018-03-09 | 共享装备股份有限公司 | High silicon spheroidal graphite cast-iron and preparation method thereof |
| CN109957631A (en) * | 2019-03-01 | 2019-07-02 | 上海烟草机械有限责任公司 | A kind of processing method of high-nickel austenite nodular cast iron melt |
-
2019
- 2019-12-27 CN CN201911380642.8A patent/CN111074034A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013117045A (en) * | 2011-12-02 | 2013-06-13 | Akebono Brake Ind Co Ltd | Thin-walled spheroidal graphite cast iron member |
| CN104975127A (en) * | 2015-06-27 | 2015-10-14 | 芜湖市容川机电科技有限公司 | Auxiliary material used for production of nodular cast iron QT600-10 |
| CN105861917A (en) * | 2016-04-14 | 2016-08-17 | 东风精密铸造有限公司 | Production method for as-cast high-performance ductile iron QT600-10 by precision-investment casting |
| CN107779737A (en) * | 2017-10-24 | 2018-03-09 | 共享装备股份有限公司 | High silicon spheroidal graphite cast-iron and preparation method thereof |
| CN109957631A (en) * | 2019-03-01 | 2019-07-02 | 上海烟草机械有限责任公司 | A kind of processing method of high-nickel austenite nodular cast iron melt |
Non-Patent Citations (1)
| Title |
|---|
| 郭新光: "高硅固溶强化球墨铸铁的研究", 《中国优秀硕士学位论文全文数据库工程科技Ⅰ辑》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111961954A (en) * | 2020-08-26 | 2020-11-20 | 上海烟草机械有限责任公司 | Preparation method of as-cast mixed matrix QT500-14 nodular cast iron |
| CN112176243A (en) * | 2020-10-30 | 2021-01-05 | 山东省源通机械股份有限公司 | Nodular cast iron material for producing explosion-proof motor casting and preparation method thereof |
| CN114836679A (en) * | 2020-10-30 | 2022-08-02 | 山东省源通机械股份有限公司 | Nodular cast iron material and preparation method and application thereof |
| CN112662937A (en) * | 2020-12-07 | 2021-04-16 | 安徽省隆兴铸造有限公司 | High-tensile-strength nodular cast iron and valve preparation method thereof |
| CN112962018A (en) * | 2021-01-29 | 2021-06-15 | 宁波日星铸业有限公司 | Chilling process manufacturing method of non-label QT600-7 nodular cast iron |
| CN112962018B (en) * | 2021-01-29 | 2022-04-01 | 宁波日星铸业有限公司 | Chilling process manufacturing method of non-label QT600-7 nodular cast iron |
| CN115595496A (en) * | 2022-10-20 | 2023-01-13 | 无锡烨隆精密机械股份有限公司（Cn） | QT600 nodular cast iron and preparation method thereof |
| CN115595496B (en) * | 2022-10-20 | 2024-03-15 | 无锡烨隆精密机械股份有限公司 | QT600 nodular cast iron and preparation method thereof |
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