阅读说明：本技术 一种球墨铸铁用球化剂及其制备方法 (Nodulizer for nodular cast iron and preparation method thereof ) 是由 俞家华 于 2020-11-11 设计创作，主要内容包括：本发明涉及球化剂制备领域,具体涉及一种球墨铸铁用球化剂及其制备方法。本发明一种球墨铸铁用球化剂包括:Si:40～44wt％,Re：2.5～4.0wt％,Mg:7.5～8.5wt％,Ca:1～2％wt,Fe:30～50％wt,Ce：1～4％wt。本发明首先对球化剂熔炼：先加入Mg、Si；熔化初期,中频炉功率调到160kW,待到Mg锭完全熔化,将功率调至100kW；开炉后5min开始插钎；炉料完全熔化后,停止插钎,然后开始搅拌,直到颗粒状的Si、Fe、Ce完全熔化为止,每炉次的熔化时间控制在45min,制得金属液；然后将金属液对钵体内浇注；待钵体内的金属液完全固化冷却后,砸碎筛选。本发明减少了镁元素的烧损,提高了镁元素的有效利用率,减少污染,对环境产生友好化的效果。(The invention relates to the field of preparation of nodulizers, and particularly relates to a nodulizer for nodular cast iron and a preparation method thereof. The nodulizer for the nodular cast iron comprises 40-44 wt% of Si, Re: 2.5-4.0 wt%, 7.5-8.5 wt% of Mg, 1-2 wt% of Ca, 30-50 wt% of Fe, and the weight ratio of Ce: 1 to 4% wt. The invention firstly smelts the nodulizer: firstly, adding Mg and Si; in the initial stage of melting, adjusting the power of the intermediate frequency furnace to 160kW, and adjusting the power to 100kW when the Mg ingot is completely melted; starting to insert the drill rod 5min after the furnace is opened; after the furnace burden is completely melted, stopping inserting the drill rod, and then starting stirring until the granular Si, Fe and Ce are completely melted, wherein the melting time of each furnace is controlled to be 45min, so as to prepare molten metal; then pouring molten metal into the pot body; and smashing and screening after the molten metal in the pot body is completely solidified and cooled. The invention reduces the burning loss of the magnesium element, improves the effective utilization rate of the magnesium element, reduces pollution and has friendly effect on the environment.)

1. The nodulizer for nodular cast iron is characterized by comprising 40-44 wt% of Si, Re: 2.5-4.0 wt%, Mg 7.5-8.5 wt%, Ca 1-2 wt%, Fe 30-50 wt%, Ce: 1-4% wt.

2. The preparation method of the nodulizer for the nodular cast iron is characterized by comprising the following steps of:

step one, nodulizer smelting: firstly, adding Mg and Si to melt the Mg and combine the Mg with the Si to generate an Mg-Si phase; in the initial stage of melting, the power of the intermediate frequency furnace is adjusted to 160kW, and when Mg is completely melted, the power is adjusted to 100 kW; starting to insert the drill rod 5min after the furnace is opened; after the furnace burden is completely melted, stopping inserting the drill rod, and then starting stirring until the granular Si, Fe and Ce are completely melted, wherein the melting time of each furnace is controlled to be 45min, so as to prepare molten metal;

step two, pouring: before casting, placing the pot body in a casting position in front of the furnace body; a pig iron cooling plate is placed in the pot body in parallel, and when in pouring, the molten metal is enabled to be opposite to the center of the pot body;

step three, crushing a nodulizer: and after the molten metal in the pot body is completely solidified and cooled, preparing a nodulizer, pouring out the nodulizer, taking out a pig iron cooling plate, smashing the massive nodulizer by using a mallet, screening the smashed nodulizer by using a square-hole sieve, bagging the screened nodulizer, and storing the bagged nodulizer in a dry place.

3. The method for preparing a nodulizer for nodular cast iron according to claim 2, wherein the inserted drill rod is inserted once every 5min after being made of round steel or threaded steel with a diameter of 18 to 22; the requirement of inserting the borer is to insert a hole in the center of the hearth, and insert 4 holes around the hearth, the hole depth is to the bottom.

4. The method for preparing a nodulizer for nodular cast iron according to claim 2, wherein the side length of the pig iron cooling plate is about 380mm, and the thickness is 35 mm.

5. The method of claim 2, wherein the bowl is an open-topped vessel having a length of 500mm, a width of 500mm and a height of 250mm, and the bowl is made of a steel plate having a thickness of 16 mm.

6. The method for preparing a nodulizer for nodular cast iron according to claim 2, wherein the square mesh sieve has a mesh size of 8 mm.

7. The method for preparing a nodulizer for nodular cast iron as claimed in claim 2, wherein the pouring temperature is 1250-.

Technical Field

The invention relates to the field of preparation of nodulizers, and particularly relates to a nodulizer for nodular cast iron and a preparation method thereof.

Background

The nodular cast iron is an important engineering material with excellent comprehensive performance, is increasingly widely applied in industry, and is one of the most main means for obtaining the nodular cast iron at present when nodulizing is carried out by using a nodulizer.

At present, the rare earth magnesium alloy is widely adopted in China, and the nodulizer has the main problems that: magnesium is easy to oxidize in the casting process of the nodulizer, the content of effective magnesium element in the nodulizer needs to be further improved, and the structure density of the nodulizer is not stable; in the spheroidizing process, the magnesium element is seriously oxidized and burnt, the absorption rate of effective elements is low, a large amount of white smoke is generated by magnesium combustion, the environment is polluted, and the adding amount of a spheroidizing agent is large.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a nodulizer for nodular cast iron and a preparation method thereof.

The nodulizer for the nodular cast iron comprises 40-44 wt% of Si, Re: 2.5-4.0 wt%, 7.5-8.5 wt% of Mg, 1-2 wt% of Ca, 30-50 wt% of Fe, and the weight ratio of Ce: 1 to 4% wt.

The preparation method of the nodulizer for the nodular cast iron comprises the following steps:

step one, nodulizer smelting: firstly, Mg and Si are added, Mg is melted and then combined with Si to generate an Mg-Si phase, and the Mg-Si phase exists all the time in the melting and pouring processes, so that the effect of reducing the oxidation burning loss of Mg is realized; in the initial stage of melting, adjusting the power of the intermediate frequency furnace to 160kW, and adjusting the power to 100kW when the Mg ingot is completely melted; starting to insert the drill rod 5min after the furnace is opened; after the furnace burden is completely melted, stopping inserting the drill rod, and then starting stirring until the granular Si, Fe and Ce are completely melted, wherein the melting time of each furnace is controlled to be 45min, so as to prepare molten metal;

step two, pouring: before casting, placing the pot body in a casting position in front of the furnace body; a pig iron cooling plate is flatly placed in the pot body, and when the pig iron cooling plate is poured, the molten metal is enabled to be opposite to the center of the pot body, so that the splashing of the molten metal is reduced;

step three, crushing a nodulizer: after the molten metal in the pot body is completely solidified and cooled, preparing a nodulizer, pouring out the nodulizer, taking out a pig iron cooling plate, crushing a large-block nodulizer by using a mallet, screening the crushed nodulizer by using a square-hole sieve, and recovering the screened small-particle nodulizer for use in a next smelting return charge; the screened nodulizer is bagged and stored in a dry place to prevent the nodulizer from being affected with damp, so that the using effect is not influenced.

Furthermore, the inserted drill rod is made of round steel or threaded steel with the diameter of 18-22 mm and then inserted once every 5 min; the requirement of inserting the borer is to insert a hole in the center of the hearth, and insert 4 holes around the hearth, the hole depth is to the bottom.

Furthermore, the side length of the pig iron cooling plate is about 380mm, and the thickness of the pig iron cooling plate is 35 mm.

Further, the bowl is an open-topped vessel 500mm long by 500mm wide by 250mm high and is made of 16mm thick steel plate.

Further, the casting temperature of the nodulizer is 1250-1300 ℃.

Further, the hole specification of the square hole sieve is 8 mm.

Compared with the prior art, the invention reduces the burning loss of the magnesium element, improves the effective utilization rate of the magnesium element, reduces pollution and has environment-friendly effect, and meanwhile, a proper spheroidizing process is selected when the nodular cast iron is produced, the addition of a spheroidizing agent is reduced, the use cost of the spheroidizing agent is effectively reduced, and the invention has good social benefit and economic benefit.

Detailed Description

The invention provides a nodulizer for nodular cast iron and a preparation method thereof, aiming at realizing a high-quality nodulizer.

The present invention will be further described with reference to the following examples, which are preferred embodiments of the present invention.

Example 1

The embodiment is a nodulizer for nodular cast iron, which comprises 40 wt% of Si, Re: 2.5 wt%, Mg 7.5 wt%, Ca 2 wt%, Fe 44 wt%, Ce: 4% wt.

The invention relates to a preparation method of a nodulizer for nodular cast iron, which comprises the following steps:

step one, nodulizer smelting: firstly, Mg and Si are added, Mg is melted and then combined with Si to generate an Mg-Si phase, and the Mg-Si phase exists all the time in the melting and pouring processes, so that the effect of reducing the oxidation burning loss of Mg is realized; in the initial stage of melting, adjusting the power of the intermediate frequency furnace to 160kW, and adjusting the power to 100kW when the Mg ingot is completely melted; starting to insert the drill rod 5min after the furnace is opened; after the furnace burden is completely melted, stopping inserting the drill rod, and then starting stirring until the granular Si, Fe and Ce are completely melted, wherein the melting time of each furnace is controlled to be 45min, so as to prepare molten metal;

step two, pouring: before casting, placing the pot body in a casting position in front of the furnace body; a pig iron cooling plate is flatly placed in the pot body, and when the pig iron cooling plate is poured, the molten metal is enabled to be opposite to the center of the pot body, so that the splashing of the molten metal is reduced;

step three, crushing a nodulizer: after the molten metal in the pot body is completely solidified and cooled, preparing a nodulizer, pouring out the nodulizer, taking out a pig iron cooling plate, crushing a large-block nodulizer by using a mallet, screening the crushed nodulizer by using a square-hole sieve, and recovering the screened small-particle nodulizer for use in a next smelting return charge; the screened nodulizer is bagged and stored in a dry place to prevent the nodulizer from being affected with damp, so that the using effect is not influenced.

Preferably, the inserted drill rod is made of round steel or threaded steel with the diameter of 18-22 mm and then inserted once every 5 min; the requirement of inserting the borer is to insert a hole in the center of the hearth, and insert 4 holes around the hearth, the hole depth is to the bottom.

Preferably, the side length of the pig iron cooling plate is about 380mm, and the thickness of the pig iron cooling plate is 35 mm.

Preferably the bowl is an open topped vessel 500mm long by 500mm wide by 250mm high and is made from 16mm thick steel plate.

Preferably, the casting temperature of the nodulizer is 1250-1300 ℃.

Preferably, the square hole sieve has a hole size of 8 mm.

Example 2

This example is a nodulizer for nodular cast iron, comprising 44 wt% of Si, Re: 2.5 wt%, Mg 8.5 wt%, Ca 1 wt%, Fe 42 wt%, Ce: 2% wt.

The invention relates to a preparation method of a nodulizer for nodular cast iron, which comprises the following steps:

step one, nodulizer smelting: firstly, Mg and Si are added, Mg is melted and then combined with Si to generate an Mg-Si phase, and the Mg-Si phase exists all the time in the melting and pouring processes, so that the effect of reducing the oxidation burning loss of Mg is realized; in the initial stage of melting, adjusting the power of the intermediate frequency furnace to 160kW, and adjusting the power to 100kW when the Mg ingot is completely melted; starting to insert the drill rod 5min after the furnace is opened; after the furnace burden is completely melted, stopping inserting the drill rod, and then starting stirring until the granular Si, Fe and Ce are completely melted, wherein the melting time of each furnace is controlled to be 45min, so as to prepare molten metal;

step two, pouring: before casting, placing the pot body in a casting position in front of the furnace body; a pig iron cooling plate is flatly placed in the pot body, and when the pig iron cooling plate is poured, the molten metal is enabled to be opposite to the center of the pot body, so that the splashing of the molten metal is reduced;

step three, crushing a nodulizer: after the molten metal in the pot body is completely solidified and cooled, preparing a nodulizer, pouring out the nodulizer, taking out a pig iron cooling plate, crushing a large-block nodulizer by using a mallet, screening the crushed nodulizer by using a square-hole sieve, and recovering the screened small-particle nodulizer for use in a next smelting return charge; the screened nodulizer is bagged and stored in a dry place to prevent the nodulizer from being affected with damp, so that the using effect is not influenced.

Preferably, the inserted drill rod is made of round steel or threaded steel with the diameter of 18-22 mm and then inserted once every 5 min; the requirement of inserting the borer is to insert a hole in the center of the hearth, and insert 4 holes around the hearth, the hole depth is to the bottom.

Preferably, the side length of the pig iron cooling plate is about 380mm, and the thickness of the pig iron cooling plate is 35 mm.

Preferably the bowl is an open topped vessel 500mm long by 500mm wide by 250mm high and is made from 16mm thick steel plate.

Preferably, the casting temperature of the nodulizer is 1250-1300 ℃.

Preferably, the square hole sieve has a hole size of 8 mm.

Example 3

The embodiment is a nodulizer for nodular cast iron, which comprises 43 wt% of Si, Re: 4.0 wt%, Mg 8 wt%, Ca 1 wt%, Fe 40 wt%, Ce: 4% wt.

The invention relates to a preparation method of a nodulizer for nodular cast iron, which comprises the following steps:

step one, nodulizer smelting: firstly, Mg and Si are added, Mg is melted and then combined with Si to generate an Mg-Si phase, and the Mg-Si phase exists all the time in the melting and pouring processes, so that the effect of reducing the oxidation burning loss of Mg is realized; in the initial stage of melting, adjusting the power of the intermediate frequency furnace to 160kW, and adjusting the power to 100kW when the Mg ingot is completely melted; starting to insert the drill rod 5min after the furnace is opened; after the furnace burden is completely melted, stopping inserting the drill rod, and then starting stirring until the granular Si, Fe and Ce are completely melted, wherein the melting time of each furnace is controlled to be 45min, so as to prepare molten metal;

step two, pouring: before casting, placing the pot body in a casting position in front of the furnace body; a pig iron cooling plate is flatly placed in the pot body, and when the pig iron cooling plate is poured, the molten metal is enabled to be opposite to the center of the pot body, so that the splashing of the molten metal is reduced;

step three, crushing a nodulizer: after the molten metal in the pot body is completely solidified and cooled, preparing a nodulizer, pouring out the nodulizer, taking out a pig iron cooling plate, crushing a large-block nodulizer by using a mallet, screening the crushed nodulizer by using a square-hole sieve, and recovering the screened small-particle nodulizer for use in a next smelting return charge; the screened nodulizer is bagged and stored in a dry place to prevent the nodulizer from being affected with damp, so that the using effect is not influenced.

Preferably, the inserted drill rod is made of round steel or threaded steel with the diameter of 18-22 mm and then inserted once every 5 min; the requirement of inserting the borer is to insert a hole in the center of the hearth, and insert 4 holes around the hearth, the hole depth is to the bottom.

Preferably, the side length of the pig iron cooling plate is about 380mm, and the thickness of the pig iron cooling plate is 35 mm.

Preferably the bowl is an open topped vessel 500mm long by 500mm wide by 250mm high and is made from 16mm thick steel plate.

Preferably, the casting temperature of the nodulizer is 1250-1300 ℃.

Preferably, the square hole sieve has a hole size of 8 mm.

Example 4

This example is a nodulizer for nodular cast iron, comprising Si 41 wt%, Re: 3 wt% of Mg, 8 wt% of Ca, 2 wt% of Fe, 44 wt% of Ce: 2% wt.

The invention relates to a preparation method of a nodulizer for nodular cast iron, which comprises the following steps:

step one, nodulizer smelting: firstly, Mg and Si are added, Mg is melted and then combined with Si to generate an Mg-Si phase, and the Mg-Si phase exists all the time in the melting and pouring processes, so that the effect of reducing the oxidation burning loss of Mg is realized; in the initial stage of melting, adjusting the power of the intermediate frequency furnace to 160kW, and adjusting the power to 100kW when the Mg ingot is completely melted; starting to insert the drill rod 5min after the furnace is opened; after the furnace burden is completely melted, stopping inserting the drill rod, and then starting stirring until the granular Si, Fe and Ce are completely melted, wherein the melting time of each furnace is controlled to be 45min, so as to prepare molten metal;

step two, pouring: before casting, placing the pot body in a casting position in front of the furnace body; a pig iron cooling plate is flatly placed in the pot body, and when the pig iron cooling plate is poured, the molten metal is enabled to be opposite to the center of the pot body, so that the splashing of the molten metal is reduced;

step three, crushing a nodulizer: after the molten metal in the pot body is completely solidified and cooled, preparing a nodulizer, pouring out the nodulizer, taking out a pig iron cooling plate, crushing a large-block nodulizer by using a mallet, screening the crushed nodulizer by using a square-hole sieve, and recovering the screened small-particle nodulizer for use in a next smelting return charge; the screened nodulizer is bagged and stored in a dry place to prevent the nodulizer from being affected with damp, so that the using effect is not influenced.

Preferably, the inserted drill rod is made of round steel or threaded steel with the diameter of 18-22 mm and then inserted once every 5 min; the requirement of inserting the borer is to insert a hole in the center of the hearth, and insert 4 holes around the hearth, the hole depth is to the bottom.

Preferably, the side length of the pig iron cooling plate is about 380mm, and the thickness of the pig iron cooling plate is 35 mm.

Preferably the bowl is an open topped vessel 500mm long by 500mm wide by 250mm high and is made from 16mm thick steel plate.

Preferably, the casting temperature of the nodulizer is 1250-1300 ℃.

Preferably, the square hole sieve has a hole size of 8 mm.

Example 5

This example is a nodulizer for nodular cast iron, comprising Si 41 wt%, Re: 4.0 wt%, Mg 8.2 wt%, Ca 2 wt%, Fe 40.8 wt%, Ce: 4% wt.

The invention relates to a preparation method of a nodulizer for nodular cast iron, which comprises the following steps:

step one, nodulizer smelting: firstly, Mg and Si are added, Mg is melted and then combined with Si to generate an Mg-Si phase, and the Mg-Si phase exists all the time in the melting and pouring processes, so that the effect of reducing the oxidation burning loss of Mg is realized; in the initial stage of melting, adjusting the power of the intermediate frequency furnace to 160kW, and adjusting the power to 100kW when the Mg ingot is completely melted; starting to insert the drill rod 5min after the furnace is opened; after the furnace burden is completely melted, stopping inserting the drill rod, and then starting stirring until the granular Si, Fe and Ce are completely melted, wherein the melting time of each furnace is controlled to be 45min, so as to prepare molten metal;

step two, pouring: before casting, placing the pot body in a casting position in front of the furnace body; a pig iron cooling plate is flatly placed in the pot body, and when the pig iron cooling plate is poured, the molten metal is enabled to be opposite to the center of the pot body, so that the splashing of the molten metal is reduced;

step three, crushing a nodulizer: after the molten metal in the pot body is completely solidified and cooled, preparing a nodulizer, pouring out the nodulizer, taking out a pig iron cooling plate, crushing a large-block nodulizer by using a mallet, screening the crushed nodulizer by using a square-hole sieve, and recovering the screened small-particle nodulizer for use in a next smelting return charge; the screened nodulizer is bagged and stored in a dry place to prevent the nodulizer from being affected with damp, so that the using effect is not influenced.

Preferably, the inserted drill rod is made of round steel or threaded steel with the diameter of 18-22 mm and then inserted once every 5 min; the requirement of inserting the borer is to insert a hole in the center of the hearth, and insert 4 holes around the hearth, the hole depth is to the bottom.

Preferably, the side length of the pig iron cooling plate is about 380mm, and the thickness of the pig iron cooling plate is 35 mm.

Preferably the bowl is an open topped vessel 500mm long by 500mm wide by 250mm high and is made from 16mm thick steel plate.

Preferably, the casting temperature of the nodulizer is 1250-1300 ℃.

Preferably, the square hole sieve has a hole size of 8 mm.

Example 6

The embodiment is a nodulizer for nodular cast iron, which comprises 43 wt% of Si, Re: 3.5 wt%, Mg 7.5 wt%, Ca 1 wt%, Fe 41 wt%, Ce: 4% wt.

The invention relates to a preparation method of a nodulizer for nodular cast iron, which comprises the following steps:

step one, nodulizer smelting: firstly, Mg and Si are added, Mg is melted and then combined with Si to generate an Mg-Si phase, and the Mg-Si phase exists all the time in the melting and pouring processes, so that the effect of reducing the oxidation burning loss of Mg is realized; in the initial stage of melting, adjusting the power of the intermediate frequency furnace to 160kW, and adjusting the power to 100kW when the Mg ingot is completely melted; starting to insert the drill rod 5min after the furnace is opened; after the furnace burden is completely melted, stopping inserting the drill rod, and then starting stirring until the granular Si, Fe and Ce are completely melted, wherein the melting time of each furnace is controlled to be 45min, so as to prepare molten metal;

step two, pouring: before casting, placing the pot body in a casting position in front of the furnace body; a pig iron cooling plate is flatly placed in the pot body, and when the pig iron cooling plate is poured, the molten metal is enabled to be opposite to the center of the pot body, so that the splashing of the molten metal is reduced;

step three, crushing a nodulizer: after the molten metal in the pot body is completely solidified and cooled, preparing a nodulizer, pouring out the nodulizer, taking out a pig iron cooling plate, crushing a large-block nodulizer by using a mallet, screening the crushed nodulizer by using a square-hole sieve, and recovering the screened small-particle nodulizer for use in a next smelting return charge; the screened nodulizer is bagged and stored in a dry place to prevent the nodulizer from being affected with damp, so that the using effect is not influenced.

Preferably, the inserted drill rod is made of round steel or threaded steel with the diameter of 18-22 mm and then inserted once every 5 min; the requirement of inserting the borer is to insert a hole in the center of the hearth, and insert 4 holes around the hearth, the hole depth is to the bottom.

Preferably, the side length of the pig iron cooling plate is about 380mm, and the thickness of the pig iron cooling plate is 35 mm.

Preferably the bowl is an open topped vessel 500mm long by 500mm wide by 250mm high and is made from 16mm thick steel plate.

Preferably, the casting temperature of the nodulizer is 1250-1300 ℃.

Preferably, the square hole sieve has a hole size of 8 mm.

The nodulizer prepared in the embodiment 1-5 is applied to nodular cast iron, and the process comprises the following steps: molten iron is smelted in an intermediate frequency electric furnace, and then spheroidization is carried out in a ladle, wherein the spheroidizing agent accounts for 2% of the mass of the molten iron, and the component of the spheroidizing agent is taken as a single variable, so that the effect of the spheroidizing agent coated by iron can be seen, the spheroidization reaction is relatively stable, and the violent reaction is effectively avoided.

Then, metallographic structures were prepared from the nodular cast iron to which the nodulizing agent prepared in each example was applied, and the results obtained were as shown in table 1:

	DETAILED DESCRIPTIONS
		Example 1	Most of the graphite is spherical and a little of the graphite is flocculent
Example 2	Most of the graphite is flocculent and nodular, and the rest is vermicular
		Example 3	The graphite is mostly vermicular and globular
Example 4	The graphite is spherical and is in a small amount of balls
		Example 5	The graphite is spherical and is in a small amount of balls
Example 6	Most of the graphite is in the shape of ball and sphere, the rest is flocculent, and a small amount of the graphite is in the shape of worm

TABLE 1

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.