JP2017214639A - Cover material, spheroidizing agent and desulfurization agent for sandwich method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an additive used for a spheroidizing treatment by a spheroidal graphite cast iron sandwiching method hardly floating and high in Mg yield.SOLUTION: There are provided a spheroidizing agent Y-Y, a cover material x-X, an inoculant and a desulfurization agent for manufacturing a spheroidal graphite cast iron capable of a spheroidizing treatment by a sandwich method of a cupola molten metal or blast furnace molten metal by preventing floating of a desulfurization agent or the like small in specific gravity with coating a FeSi-Mg alloy or an additive such as a lime cake with a phenol novolak resin and by increasing retention time in the molten metal and enhancing yield of Mg of the spheroidizing agent to 70 to 80% with enhancing desulfurization effect using a main material of the cover material as the desulfurization agent.SELECTED DRAWING: Figure 1

Description

Detailed Description of the Invention

Industrial application fields

The additive of the present invention relates to an additive applied in the case of spheroidizing the molten metal melted in an electric furnace or cupola before pouring into a mold in the production of spheroidal graphite cast iron. The present invention relates to an additive that contributes to the prevention of global warming by reducing the amount of carbon dioxide generated by reducing the cost and the working environment by reducing the amount of conventional additives and by reducing the energy consumption by omitting the remelting process of the cold material.

Conventionally, when producing spheroidal graphite cast iron, a spheroidizing agent is installed at the bottom of the processing vessel (hereinafter referred to as ladle), and the top is punched and covered with steel plate scraps, nail head chips, machine shavings, etc. The molten metal that has been spheroidized by the pouring method that injects the molten metal whose components have been adjusted later is injected into the mold, and this method has various problems that will be described later. The situation is that we are struggling with countermeasures but have not yet solved the problem.

Unresolved issues

As an unsolved problem, the problems described below exist as an unsolved problem. 1) If molten metal is injected, the additive treatment agent rises.
2) Spherical-inhibiting components S and Mn may be mixed from scraps and processing additives, and it is necessary to desulfurize the treated molten metal in advance to maintain and stabilize the spheroidizing efficiency before the sizing agent starts the reaction. There is.
Does not contain other metal chemical components that inhibit spheronization.
3) The necessary amount cannot be obtained at any time when necessary.
4) Since a metal cover material is used, the molten metal temperature tends to drop.
5) Since the metal cover material has a high specific gravity, a large amount of cover material is required to sufficiently cover the spheroidizing agent.

Means to solve the problem

In the past, additives such as spheroidizing agents and desulfurizing materials have a specific gravity smaller than that of molten metal, and as a matter of course, they have to be pressed down with a metal cover material to prevent ascent. However, there is a need for a cover material that can be used to solve the various problems. The cover material of the present invention described below can solve various problems in general, and it is assumed that the cover material is more efficient than the conventional method. As a result of the implementation, it has been found that there is a possibility that an efficient and low electric energy spheroidizing treatment can be realized by using a cover material exclusively for the spheroidizing treatment of the present invention and a commercially available spheroidizing agent. Therefore, the characteristics of the cover material of the present invention require the following conditions, and it is important that they can be solved. For this purpose, the additive is first coated with phenol novolac resin, so that even desulfurization materials with low specific gravity can be used as a cover material without floating, and the main material is conventional steel scrap. As a result of various studies and searches, it was found that there was a strong possibility that most problems could be solved by using a desulfurizing agent instead of a cover agent. These countermeasures / means are described in FIGS. 1 to 5 and Table 1, and the actual implementation results are described in Table 1.
Phenol novolac resin is a popular phenol resin widely used in the automobile industry. As a prerequisite,
1) Raw materials must be readily available at home and abroad.
2) By heating to about 200 ° C., a strong cover material hardened wall layer is formed between the spheroidizing agent and the molten metal, and the molten metal is prevented from entering the spheroidizing agent without floating until it is lost. This prevents the spheroidizing agent from rising and encourages the start of the rescue reaction at the bottom of the pan.
3) Having a desulfurization function.
4) Do not contain harmful components for spheroidization.
5) Good storage, easy on-site inventory and no danger.
6) There must be no generation of harmful gases that cause work environment deterioration or pollution.

図４にワンセットコアー実施時の設置状況の側面図を記載する。図中適切な設置位置に取鍋の底部にコアー設置用の凹部を設けてコアーＧと設置底面との間に溶湯が潜り込んで浮力を生じさせないように正確な設置位置とコアーＧと取鍋間の隙間Ｓを充填硬化してコアーの浮上と移動を防止して確実に球状化実施を確保出来るように設計したものである。充填硬化材料としては本発明のカバー材やコーテッドサンド自硬性砂等をＳ部に充填しても対応可能である。 The design of the additive treatment and the addition method are described in FIGS. 1 to 5 and Table 1 so that the function can be exhibited for solving the problem.
In FIG. 1, A describes the shape of the cover material, and B describes the shape of the spheroidizing agent. XX describes the cross-sectional structure of A, and (b) is a lime cake, stone powder, or limestone grain mainly produced from calcium carbonate, and C is a phenol novolac resin that coats these, which occurs during the production of beet sugar. However, if this cover material is used, the intended spheroidization can be obtained even if a conventional size is used as it is. Y-Y describes the cross-sectional structure of the spheroidizing agent, @ is a fine-grained ferrosilicon Mg alloy of 3-5 mesh or less, and is similarly coated with a phenol novolac resin according to the present invention. Indicates. This spheroidizing agent does not float even without a cover material, but in the case of a high S% molten metal, a stable spherical graphitization treatment may not be possible. Therefore, it is better to use a cover material also for desulfurization treatment. Safe and good. By applying this cover material, there is an advantage that desulfurization and spheroidization can be carried out efficiently. FIG. 2 shows a side view of the state of additive installation at the time of implementation. In the figure, D indicates a conventional duct ladle with a pocket, and E indicates a general flat ladle that is widely used. The pocket ladle tends to become shallow due to the undissolved metal cover material remaining in the pocket, and there is a problem that it is necessary to frequently carry out cleaning and repair work. FIG. 2 shows a side view of the installation situation at the time of implementation. In the figure, A shows a cover material of the present invention that replaces a conventional metal cover material, and B shows a commercially available spheroidizing agent used conventionally or a spherical shape of the present invention. The shape and cross-sectional structure of the agent are shown. @ Indicates a product obtained by sizing a commercially available spheroidizing agent ferrosilicon Mg alloy and coated with a phenol novolac resin, and the main component is ferrosilicon Mg alloy or ferrosilicon. The main component of B is a commercially available Fe-Si-Mg alloy, which is a lime cake or stone powder whose main component is calcium carbonate generated during the production of A's main component beet sugar. @ Indicates a spheroidizing agent, and is a mixture of a commercially available ferrosilicon Mg alloy, ferrosilicon Mg and an inoculum.

FIG. 4 shows a side view of the installation situation when the one-set core is implemented. In the figure, an accurate installation position between the core G and the ladle is provided so that a concave part for core installation is provided at the bottom of the ladle at the appropriate installation position so that molten metal does not sink between the core G and the bottom of the installation and cause buoyancy. The gap S is filled and hardened to prevent the core from rising and moving and to ensure the spheroidization. As the filling and hardening material, the cover material of the present invention, coated sand self-hardening sand or the like can be filled in the S portion.

Implementation results

As a result of having carried out, we can obtain result that we generally assumed, and list result of city below.
Table 1 lists examples of implementation results.
From these results, the results described below can be surely obtained.
1) The cover material and spheroidizing agent of the present invention do not float.
2) There is little loss of Mg in the spheroidizing agent, and a high yield of about 70-80% is possible.
3) The cover material has a desulfurization function.
4) It becomes possible to obtain a spheroidal graphite cast iron melt by directly treating the molten cupola with CE value control.
5) Less white smoke is generated.

Effect of the invention

ノボラック樹脂を示す。このボラック樹脂は常温では個体であり、約１００℃近傍では液状で、約２００℃で熱硬化して強固な硬化層を形成する熱硬化フェノール樹脂であり、自動車産業にてコーテッドサンドに多く利用されているポピュラーなフェノール樹脂である。脱硫材に被覆して用いれば、約２００℃の低温度で球状化剤と処理溶湯間に強固な防壁を形成し、溶湯が早期に球状化剤に侵入するのを防止しＡが溶失するまで溶湯が球状化剤に侵入してくるのを防止して浮上を防止し、球状化反応開始までに脱硫機能を発揮して球状化剤の浮上を防止出来る。更に脱硫機能があれば球状化を阻害するＳを除去して球状化剤の Ｍｇロスを低減出来て高Ｓ％の銑鉄やキュポラ溶湯を直接処理して球状化溶湯を得ることが可能となる。図２に実施時の設置状況の側面図を示す。図中Ｄは主に球状化処理に使用されるポケット付取鍋を示しＥは一般的に汎用される平取鍋を示す。Ｆはカバー材硬化層に当てて破壊しないように取鍋側壁当てながら速やかに湯終了出来るように、注入する溶湯の方向を示す・脱硫材が従来の金属カバー材の代用として適用可能であれば未解決の課題を殆ど解決出来ると想定され実施結果について図面と実施結果一覧表に記載する。図１〜５に本発明のカバー材と球状化剤の形状と断面構造を記載する。図１中Ａはカバー材をＢは球状化剤を示し、Ｃはそれぞれの処理剤を被覆するか又は成形硬化するノボラック樹脂を示す。処理溶湯の注入が終了するまでに球状化剤が浮上しなければ実用実施時には球状化剤は取鍋の底部にて反応を開始することになって高溶湯圧とＡが溶失して球状化剤が個々に浮上して行っても浮上してしまうまでに溶湯中に長時間滞在可能となり、極めて穏やかで効率的反応が得られて少量の球状化剤で安定した球状黒鉛鋳鉄溶湯を得る事が可能となる。しかも反応が穏やかで浮上しないために、従来浮上の結果発生するＭＧＯ白煙が多く発生して作業環境を劣化し更に多量の金属カバー材が必要となり、５％以上のＭｇを含有する球状化剤は爆発的な反応を呈する場合があり、その使用を敬遠されがちである。図中Ｄは球状化処理専用に設計されたポケット付取鍋を示し、Ｅは一般的な汎用平取鍋を示す。取鍋の形状としては球状化剤を設置するポケットを有するのは勿論のことであり、更に球状化剤の激しい反応を抑えて危険防止を図ることと球状化剤が浮上するまでに出来るだけ長時間かかるように溶湯との接触反応時間を長くして十分な球状化反応作用を実現出来るように取鍋の高さを高く設計するのが一般的であり、例えば取鍋の高さは低部の直系の約２倍で通常野平取鍋より高い深さの形状である。
Ｆは注入する溶溶湯を直接カバー材に当てて破損しないようにしながら速やかに注入えきるように注入する溶湯の注入方向を示す図に記載するように、最初は穏やかにＦ流に従って注湯しカバー材が隠れるまではゆっくりとカバー材が溶湯の上部に到達すればその後一気に注湯してしまうのが得策である。注湯終了まで球状化剤等の添加剤の浮上が認められ

記載する。図４に実施時の設置状況の側面図を記載する。図中Ａはカバー材硬化層をＢは球状化剤、接種剤等の混合物硬化層を、Ｃは実施時にワンセットにて設置出来るように利用する吊り芯金を示す。Ｓはコアーの設置部底面に溶湯が侵入して浮力を生じさせないように、自硬性砂やシェル砂を充填・硬化させれば十分にシール可能であり、設置するＧのワンセットコアーの浮上を確実に防止できる。コアーの形状は注入した溶湯との比重差による浮力を極力発生しないように、円錐状の形状に設計する。
球状化剤を被覆するか粒状・小塊状に整成型硬化させるフェノールノボラック樹脂を示す。図２に実施時の設置状況の側面図を示し、図中Ｄは球状化処理用に設計使用されたポケット付取鍋をＥは一般的に汎用される平鍋を示し、Ｆは処理溶湯の注入方向を示し、取鍋の側壁に当てながらカバー材に直接当てないように注入する溶湯流の方向を示す。
図３、図４
図３にワンセットコアーの形状と断面構造を記載する。図中Ａは本発明のカバー材を、Ｂは球状化剤と接種剤等の混合物をフェノールノボラック樹脂で硬化したコアーを、Ｃは実施時に容易に移動、設置出来るようにコアーに組込まれた吊り芯金を。図４に実施時の設置状況の側面図を記載する。図中Ｓはワンタッチコアーの底面に溶湯が侵入してコアーに浮力を発生させないように確実にシールする部居を示しシールするために本発明のカバー材やシェル砂や自硬性砂を充填・硬化させることにより、目的を果すことが可能となる。ワンセットコアーは処理溶湯量に従って基準予め標準化したサイズのものを準備しておげば、安価で効率的に良好な球状化処理が出来る。By applying the cover material of the present invention, the following effects can be expected.
1) The cover material and spheroidizing agent of the present invention do not float.
2) The cover material has a desulfurization effect.
3) Even if there is no casting furnace only with cupola melting equipment, there is a great expectation that spheroidal graphite cast iron can be manufactured with CE value control even if there is no electric furnace melting equipment.
4) Since the ascent can be prevented, the generation of white smoke can be reduced and the working environment can be improved.
5) There is a possibility that the cupola production molten metal can be processed in that pot, and the remelting process by the electric furnace of the conventional method is omitted, and the electric energy of remelting can be remarkably reduced, and the carbon dioxide emission can be remarkably reduced. It can be realized with great promotion.
6) Casting factory with only cupola melting equipment 7) Even without investing in an electric furnace or power distribution equipment, it is possible to easily produce spheroidal graphite cast iron at the casting factory, which may greatly contribute to increased sales and profits. Is strong.
7) Since it does not float, the residence time in the molten metal is long, the reaction efficiency is high, the Mg yield is about 70% or more, and the amount added can be reduced as compared with the conventional method, and the cost can be reduced.
8) A spheroidizing agent having a high Mg content% can be efficiently and safely applied.

A novolak resin is shown. This borak resin is a solid at room temperature, is a liquid at around 100 ° C, and is a thermosetting phenolic resin that forms a strong cured layer by thermosetting at about 200 ° C, and is widely used for coated sand in the automotive industry. It is a popular phenolic resin. If used on a desulfurized material, a strong barrier is formed between the spheroidizing agent and the molten metal at a low temperature of about 200 ° C., preventing the molten metal from entering the spheroidizing agent at an early stage, and A is lost. It is possible to prevent the molten metal from entering the spheroidizing agent and prevent the spheroidizing agent from rising, and to exhibit the desulfurization function until the spheroidizing reaction starts, thereby preventing the spheroidizing agent from rising. Furthermore, if there is a desulfurization function, S that inhibits spheroidization can be removed to reduce Mg loss of the spheroidizing agent, and high S% pig iron or cupola melt can be directly processed to obtain a spheroidizing melt. FIG. 2 shows a side view of the installation situation at the time of implementation. In the figure, D indicates a ladle with pockets mainly used for spheroidizing treatment, and E indicates a generally used ladle. F indicates the direction of the molten metal to be poured, so that the hot water can be finished quickly while touching the ladle side wall so that it does not break against the hardened cover material. If the desulfurization material is applicable as a substitute for the conventional metal cover material It is assumed that most unsolved problems can be solved, and the implementation results are described in the drawings and implementation results list. The shape and cross-sectional structure of the cover material and spheroidizing agent of the present invention are shown in FIGS. In FIG. 1, A represents a cover material, B represents a spheroidizing agent, and C represents a novolak resin that coats or cures each treatment agent. If the spheroidizing agent does not rise by the end of the injection of the molten metal, the spheroidizing agent will start the reaction at the bottom of the ladle at the time of practical use, and the molten metal pressure and A will be lost and spheroidized. Even if the agent floats individually, it can stay in the molten metal for a long time until it floats, and a very mild and efficient reaction can be obtained, and a stable spheroidal graphite cast iron melt can be obtained with a small amount of spheroidizing agent. Is possible. In addition, since the reaction is mild and does not float, a large amount of MGO white smoke generated as a result of conventional floatation occurs, which deteriorates the working environment and requires a large amount of metal cover material, and a spheroidizing agent containing 5% or more of Mg. May exhibit explosive reactions and are often discouraged from their use. In the figure, D represents a ladle with a pocket designed exclusively for spheroidizing treatment, and E represents a general general-purpose ladle. Of course, the ladle has a pocket to install the spheroidizing agent, and it is as long as possible until the spheroidizing agent rises to prevent danger by suppressing the violent reaction of the spheroidizing agent. In general, the ladle height is designed to be high so that a sufficient spheroidizing reaction can be realized by increasing the contact reaction time with the molten metal so that it takes time. For example, the ladle height is low. It is about twice as large as the direct line of, and the shape is deeper than the normal Nohira ladle.
F, as shown in the figure showing the injection direction of the molten metal to be poured quickly so that the molten metal to be poured is directly applied to the cover material so that it does not break, the molten metal is first poured gently according to the F flow. It is a good idea to slowly pour hot water after the cover material reaches the top of the molten metal until the cover material is hidden. Additives such as spheroidizing agents are allowed to rise until the end of pouring

Describe. FIG. 4 shows a side view of the installation situation at the time of implementation. In the figure, A is a cover material cured layer, B is a mixture cured layer of a spheroidizing agent, an inoculant, and the like, and C is a hanging core bar that is used so that it can be installed in one set at the time of implementation. S can be sufficiently sealed by filling and curing self-hardening sand or shell sand so that molten metal does not enter the bottom of the core installation area and cause buoyancy. It can be surely prevented. The shape of the core is designed to be conical so as not to generate as much buoyancy due to the difference in specific gravity from the injected molten metal.
A phenol novolac resin that is coated with a spheroidizing agent or shaped and cured into a granular or small lump is shown. Fig. 2 shows a side view of the installation situation at the time of implementation. In the figure, D is a ladle with a pocket designed and used for spheroidizing treatment, E is a generally used pan, and F is pouring of molten treatment The direction of the molten metal to be poured so as not to be directly applied to the cover material while being applied to the side wall of the ladle.
3 and 4
FIG. 3 shows the shape and cross-sectional structure of the one-set core. In the figure, A is a cover material of the present invention, B is a core obtained by curing a mixture of a spheroidizing agent and an inoculant with a phenol novolac resin, and C is a suspension incorporated in the core so that it can be easily moved and installed at the time of implementation. A mandrel. FIG. 4 shows a side view of the installation situation at the time of implementation. In the figure, S indicates a part where the molten metal penetrates into the bottom surface of the one-touch core and does not generate buoyancy to the core, and is filled and cured with the cover material, shell sand or self-hardening sand of the present invention for sealing. By doing so, the purpose can be achieved. If the one-set core is prepared with a standardized standard size according to the amount of molten metal to be processed, a good spheroidizing treatment can be carried out inexpensively and efficiently.

Implementation results

As a result of having carried out, we can obtain result that we generally assumed, and list result of city below.
Table 1 lists examples of implementation results.
From these results, the results described below can be surely obtained.
1) The cover material and spheroidizing agent of the present invention do not float.
2) There is little loss of Mg in the spheroidizing agent, and a high yield of about 70 to 80% is possible.
3) The cover material has a desulfurization function.
4) It becomes possible to obtain a spheroidal graphite cast iron melt by directly treating the molten cupola with CE value control.
5) Less white smoke is generated.
5) The desulfurization effect of this cover material is great, and spheroidal graphite cast iron can be produced by placing and pouring blast furnace pig iron.
6) Since it does not float and the residence time in the molten metal is long, and the yield of Mg as a spheroidizing agent is as high as about 70 to 80% and the reaction efficiency is good, the addition amount of the spheronizing agent is reduced and the cost can be reduced. .

Effect of the invention

By applying the cover material of the present invention, the following effects can be expected.
1) The cover material and spheroidizing agent of the present invention do not float.
2) The cover material has a desulfurization effect.
3) Even in a casting factory with only a cupola melting facility, even if there is no electric furnace melting facility, spheroidizing treatment is possible, and it is highly possible to produce spheroidal graphite cast iron with the permission of CE value control.
4) Since the ascent can be prevented, the generation of white smoke can be reduced and the working environment can be improved.
5) There is a possibility that the cupola production molten metal can be processed in that pot, and the remelting process by the electric furnace of the conventional method is omitted, and the electric energy of remelting can be remarkably reduced, and the carbon dioxide emission can be remarkably reduced. It can be realized with great promotion.
6) Casting factory with only cupola melting equipment 7) Even without investing in an electric furnace or power distribution equipment, it is possible to easily produce spheroidal graphite cast iron at the casting factory, which may greatly contribute to increased sales and profits. Is strong.
7) Since it does not float, the residence time in the molten metal is long, the reaction efficiency is high, the Mg yield is about 70% or more, and the amount added can be reduced as compared with the conventional method, and the cost can be reduced.
8) A spheroidizing agent having a high Mg content% can be efficiently and safely applied, and the cost can be significantly reduced by further reducing the addition amount. (Expected value: -40-50%)

Detailed Description of the Invention

[Industrial application fields]

The additive material of the present invention relates to a cover material and a spheroidizing agent applied when producing spheroidal graphite cast iron. More specifically, the spheroidizing agent is melted in an electric furnace or the like before being poured into a mold, and the component is adjusted to a molten metal. Is applied to the production of spheroidal graphite cast iron by producing a spheroidized molten metal by adding a spheroidizing reaction and pouring it into a mold, and by pouring a molten melt melted in a melting blast furnace or cupola The present invention relates to an additive additive that is applied to desulfurization to produce a low S% dashi koji, and that significantly reduces electric energy consumption and contributes to prevention of global warming.

In the case of producing spheroidal graphite cast iron, conventional steel plates and machined scraps are prepared by installing a spheroidizing agent at the bottom of the ladle in a molten metal prepared by remelting the blast furnace pig iron, return material and steel scrap. , Which is covered with a metal cover material such as a nail head and pressed down to prevent the floating of the spheroidizing agent and has produced a spheroidal graphite cast iron melt, but there are still various unsolved problems as described below It exists and is being manufactured with various innovations, and there is a need to solve the problem, and the reality is that this solution is eagerly desired.

In the case of producing spheroidal graphite cast iron, a steel plate and machined scraps are punched by installing a spheroidizing agent at the bottom of the ladle in a molten metal that has been remelted from blast furnace pig iron, return material, steel scrap, etc. , Which is covered with a metal cover material such as a nail head and pressed down to prevent the floating of the spheroidizing agent and has produced a spheroidal graphite cast iron melt, but there are still various unsolved problems as described below It exists and is being manufactured with various innovations, and there is a need to solve the problem, and the reality is that this solution is eagerly desired.

Unresolved issues

The unsolved problems are as follows: 1) If the metal cover material is not pressed down, the spheroidizing agent floats and spheroidization failure occurs.
2) Because metal cover material is scrap generated in other industries, it is difficult to obtain the required amount when necessary.
3) It is difficult to specify and manage scrap chemical components generated from other industries in metal cover materials.
4) Because of the high specific gravity of the metal cover material, multiple amounts are required to cover uniformly.
5) The metal cover material is heavy and the temperature of the molten metal decreases.
6) If the S content of the treated molten metal is high, it is difficult and unstable to obtain a sufficient spheroidizing hot water even though it can be prevented from rising.
7) It is almost impossible to spheroidize cupola melt or blast furnace hot metal directly.
As described below, various issues remain, and there are a variety of issues. Currently, it is in fact necessary to make various ingenuity. The solution is anxious.

Means to solve the problem

It is said that the presence of fine Mg bubbles is important for spheroidizing the cast iron melt to be treated. Generally, if a ferrosilicon 3-5% Mg alloy is used and the treatment melt has a high S%, Since S in the molten metal and Mg in the spheroidizing agent consume Mg as MgS, spheroidization is unstable and defective, which is not useful. Therefore, it is necessary to use a material having a desulfurization function as the metal cover material, and it can be said that the anti-floating measure alone is insufficient. As a result of conducting various research and exploratory tests for the causes and countermeasures of floating in consideration of countermeasures for this problem, the treated molten metal was covered with phenol novolac resin using a desulfurization material having a specific gravity lower than that of the current spheroidizing agent. Make a strong barrier between the molten metal and the spheronizing agent by the time you reach the top. This phenol novolac resin is a liquid phenol in a temperature range of about 40 to 8 ° C. and is thermosetting at about 200 ° C. and is a popular phenol resin used for a mold in the automobile industry. Therefore, if it is added to the ladle after use, the cover material and the spheroidizing agent are bonded and hardened by the remaining heat to form a strong barrier between the spheroidizing agent and the molten metal, and until the spheroidizing agent is finished from pouring Prevents the metal from touching the molten metal and prevents the ascent. This cover material is melted at about 700 to 800 ° C. because the main material is calcium carbonate, and it takes time until it melts. After that, the spheroidizing agent can start the reaction at the bottom of the pan, so the high pressure of the molten metal. It is possible to extend the time that can be present in the molten metal, enable an efficient and gentle reaction, and prevent the loss of Mg by desulfurizing the treated molten metal in advance, and if this cover material is used even in a high S molten metal, most problems Since we were able to find that it was possible to solve the problem, we made a sample and verified the implementation. The implementation status and implementation results are shown in FIGS.

FIG. 1 shows the shape and cross-sectional structure of the cover agent. In the figure, ▲ b ▼ is a lime cake or stone powder produced during the production of sugar beet sugar mainly composed of calcium carbonate, which is processed into a granular or small lump and coated with a phenol novolac resin of C. Carbite can be considered, but it is necessary to take safety measures against fires and burn accidents due to moisture during production and acetylene gas generation during inventory storage. The spheroidizing agent @ is obtained by coating a ferrosilicon magnesium alloy containing 3-8% Mg as a main material into a granular or small lump with a phenol novolac resin. FIG. 2 shows the shape and cross-sectional structure of the spheroidizing agent. In the figure, @ indicates a mixture of a 3-8% Mg ferrosilicon magnesium alloy processed into a granular or small lump and an inoculum with a phenol novolac resin. FIG. 3 shows a side view of the installation situation at the time of implementation. In the figure, A is a cover agent layer, and B is a mixture of a spheroidizing agent and an inoculum. D is a ladle with a pocket dedicated to spheroidizing treatment. After a spheroidizing agent is placed in the pocket, a cover agent is placed on top of it and heated and cured with the residual heat of the ladle or a gas torch to form a cover agent cured layer. To do. This covering agent layer forms a strong barrier after pouring the molten metal to prevent the molten metal from entering the spheroidizing agent at an early stage to prevent the spheroidizing agent from floating, and melts and loses at 700 to 800 ° C. The molten metal is desulfurized to remove excess S that causes Mg loss to improve the efficiency of the spheroidizing agent. In order to encourage the start of the reaction at the bottom of the pan as well as to prevent ascent, the intense reaction of Mg is suppressed by the molten metal pressure at the top to reduce the generation of white smoke. In the case of D flat ladle, tilt the ladle somewhat with the handle for casting and install the spheroidizing agent. Finally, cover it with a cover agent and push it in a little so that there is no gap at the boundary. If only the surface is heat-cured, it can be covered sufficiently. In this case, it is important to keep the boundary between the cover agent and the ladle in close contact. If there is a gap at the boundary, the molten metal will sink into the gap at the time of pouring, enter the spheroidizing agent and generate buoyancy, which is an important precaution. Under conditions with no gaps, it was possible to prevent the ascent in the preliminary verification test and the results. FIG. 4 shows the shape and sectional structure of the one-set core. The core is designed to have a conical or trapezoidal shape to reduce buoyancy as much as possible. The core is composed of an A covering agent cured layer, a B spheroidizing agent, and a suspension core for moving installation. FIG. 5 shows the aspect of the installation situation at the time of implementation. In the figure, the gap S between the installation recess provided at the bottom of the ladle and the core is filled and cured with self-hardening sand, coated sand or the like to seal and prevent the core G from floating.

Implementation results

The implementation results are listed in Table 1. From this result, 1) This cover material also has a desulfurization function.
2) The cover material and spheroidizing agent of the present invention do not float.
3) By applying this cover material and the spheroidizing agent, it is possible to perform a resting treatment with a mild reaction and less white smoke.
4) By applying the cover material and the spheroidizing agent of the present invention, the possibility of spheroidizing the cupola melt, which has been difficult in the past, is further strengthened.
5) By applying this cover material, the amount of conventional spheroidizing agent added can be reduced by about 40%.
6) The cover material does not float even in the pouring method, and the addition amount of the desulfurization material having a desulfurization function and the spheroidizing agent can be reduced by about 40%.

Effect of the invention

The present invention has the following effects.
1) The cover material and the spheroidizing agent do not float.
2) This cover material has a desulfurization function.
3) The reaction becomes mild and the generation of white smoke is reduced.
4) By applying the cover material of the present invention, the amount of the spheroidizing agent can be reduced by about 40%.
5) There is a great possibility that the cupola melt can be spheroidized in the molten state with CE value control.
6) When producing low S% duct cake by desulfurizing blast furnace pig iron by the pouring method, it can be produced using a general-purpose ladle as it is.
7) Because cupola melt can be directly spheroidized, it contributes to the prevention of global warming by significantly reducing consumption of the most melted electric energy.

Claims (8)

When producing spheroidal graphite cast iron, molten metal additives such as spheroidizing agents and inoculant desulfurizing agents are installed at the bottom of the processing vessel, and molten metal is injected into the upper part to produce a spheroidized molten metal. A candy-shaped, granular or small spheroidizing agent, inoculant, desulfurizing material, characterized in that the additive is coated, shaped and bonded and cured with a phenol novolac resin. A main material is a granular material or a small lump of lime cake or stone powder and limestone grains mainly composed of calcium carbonate generated during the production of FeSi-Mg alloy or sugar beet sugar, and the cover material having the characteristics described in claim 1 , Desulfurization material. A spheroidizing agent, a cover material, an inoculant, and a desulfurization material having the characteristics described in claim 1, wherein a mixture of a ferrosilicon-magnesium alloy and a lime cake inoculant is coated and cured with a phenol novolac resin. A desulfurization material having the characteristics described in claim 1 or 2, wherein a desulfurization material used when desulfurizing a blast furnace pig iron and producing a low S% ductile iron by a pouring method is used. It has a feature that the outside is composed of the cured layer of the cover material of the present invention and the inside is composed of a cured layer of a mixture of a spheroidizing agent, an inoculating agent, etc. and a hanging core so that it can be processed in one set for the pouring method. One set core. A phenol novolac resin having a feature described in claims 1 to 5 containing a lime cake or a ferrosilicon Mg component in a phenol novolac resin that coats, molds, and hardens an additive treatment agent. The spheroidizing agent having the characteristics described in claim 1 or 2, wherein a ferrosilicon Mg alloy processed to 3 to 5 mesh or less is coated with a phenol novolac resin. A desulfurization material used when producing low S% duct cake by desulfurizing blast furnace pig iron and molten cupola.

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