JPH0346211B2 - - Google Patents
Info
- Publication number
- JPH0346211B2 JPH0346211B2 JP10487586A JP10487586A JPH0346211B2 JP H0346211 B2 JPH0346211 B2 JP H0346211B2 JP 10487586 A JP10487586 A JP 10487586A JP 10487586 A JP10487586 A JP 10487586A JP H0346211 B2 JPH0346211 B2 JP H0346211B2
- Authority
- JP
- Japan
- Prior art keywords
- sand
- mold
- slag
- olivine
- added
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 126
- 239000004576 sand Substances 0.000 claims description 76
- 239000002893 slag Substances 0.000 claims description 26
- 239000000377 silicon dioxide Substances 0.000 claims description 25
- 229910052609 olivine Inorganic materials 0.000 claims description 23
- 239000010450 olivine Substances 0.000 claims description 23
- 238000003723 Smelting Methods 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 2
- 229910052681 coesite Inorganic materials 0.000 claims description 2
- 229910052593 corundum Inorganic materials 0.000 claims description 2
- 229910052906 cristobalite Inorganic materials 0.000 claims description 2
- 239000012535 impurity Substances 0.000 claims description 2
- 235000012239 silicon dioxide Nutrition 0.000 claims description 2
- 229910052682 stishovite Inorganic materials 0.000 claims description 2
- 229910052905 tridymite Inorganic materials 0.000 claims description 2
- 229910001845 yogo sapphire Inorganic materials 0.000 claims description 2
- 238000000034 method Methods 0.000 description 20
- 238000005266 casting Methods 0.000 description 14
- 238000005336 cracking Methods 0.000 description 13
- 230000000694 effects Effects 0.000 description 11
- 239000010410 layer Substances 0.000 description 9
- 239000011347 resin Substances 0.000 description 7
- 229920005989 resin Polymers 0.000 description 7
- 238000004519 manufacturing process Methods 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 238000010112 shell-mould casting Methods 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 238000007788 roughening Methods 0.000 description 4
- 230000003746 surface roughness Effects 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000003110 molding sand Substances 0.000 description 3
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 238000001000 micrograph Methods 0.000 description 2
- -1 olivine sand Chemical compound 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 230000003014 reinforcing effect Effects 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- 206010013786 Dry skin Diseases 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- 239000012778 molding material Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
Landscapes
- Mold Materials And Core Materials (AREA)
Description
（産業上の利用分野）
本発明はシエルモールド法により鋳造品を製造
する際に用いられる鋳物砂に関するもので、特に
シエル鋳型に溶湯を注入する際発生する鋳型ガス
および鋳型の膨張に起因する鋳物表面の浸炭、肌
荒れおよび鋳型割れなどを防止できるシエルモー
ルド用鋳物砂に関するものである。
（従来の技術）
シエルモールド鋳造品におけるシエル鋳型に起
因する鋳型ガスによる鋳物表面の肌荒れおよび浸
炭層の生成は有害であり、とくに製造時における
割れなどの発生原因となるものである。
このようなシエル鋳型に起因する鋳型ガスによ
る鋳物表面の肌荒れおよび浸炭防止方法として、
(1)鋳物砂中にベンガラを添加する方法、(2)塗型材
を用いる方法、(3)焼結し易い特性を有するオリビ
ン砂などの鋳物砂を添加させる方法、(4)昭和57.3
月．p19綜合鋳物センター：有機自硬性鋳型にお
ける鋳造欠陥とその対策事例に示されているL.O.
I.樹脂の添加量の制限などによる操業管理による
方法などが知られている。
一方、シエル鋳型に溶湯を注入する際発生する
鋳型の膨張に起因する鋳型割れは致命的な問題で
あり、割れ防止の方法として、(5)鋳型の鋳物砂の
砂厚の増加または砂粒およびシヨツト玉により補
強する方法、(6)線膨張係数の小さい、従つて熱膨
張率の小さくなるオリビン砂などを添加する方法
などが知られている。
（発明が解決しようとする問題点）
前記シエル鋳型に起因する鋳物表面の肌荒れお
よび浸炭防止方法(1)〜(4)の方法は下記の点に問題
がある。すなわち、前記(1)の鋳物砂中にベンガラ
を添加する方法は、ベンガラを添加すると発生ガ
スと反応して溶湯中に活性ガスを出さないように
する効果があるが、効果を出すためには微粉状に
する必要があり、微粉状にするとそれだけレジン
添加量が増加するので有効な手段とは言えない。
前記(2)の塗型材を用いる方法は、欠陥防止効果は
期待できても塗型材の費用が必要となると共に、
塗型塗布工程が増え製造コストが増加する。前記
(3)のオリビン砂などの鋳物砂を混入させる方法
は、珪砂中に焼結し易い特性を有するオリビン砂
を添加することによつて、注湯時にオリビン砂が
焼結し強固な被膜を形成するため、肌荒れ、浸炭
を防止する効果がある。しかしオリビン砂は高価
なためコストが増加する。
一方前記シエル鋳型に溶湯を注入する際発生す
る鋳型の膨張に起因する鋳型割れの防止方法(5)〜
(6)の方法は、下記の点に問題がある。すなわち、
前記(5)の鋳型の鋳物砂の砂厚を増加するなど方法
は、補強作業という工数増大によりコストが増加
する。前記(6)のオリビン砂などを添加させる方法
は、線膨張係数の小さいオリビン砂を骨材として
使用することによつて、注湯時の型割れ防止効果
は認められるが、オリビン砂は高価であり、さら
に砂の粒型に起因してレジン量も増加する必要が
あるためコストが増加する。
本発明の目的は、従来技術の有する注湯時の型
割れおよび鋳物表面の肌荒れ、浸炭を生ずること
なしにシエルモールド鋳物を製造できる鋳物砂を
提供することにある。
（問題点を解決するための手段）
前記目的を達成するための鋳物砂の構成とし
て、本発明は、MgO：27〜33wt％、SiO2：48〜
58wt％、Al2O3：１〜3wt％、FeO：５〜11wt
％、CaO：４〜6wt％、残部不可避的不純物から
なる成分組成を有して、線膨張係数がオリビン砂
相当のものであるフエロニツケル鉱石製錬鉱滓15
〜17wt％と、残部珪砂との混合物からなるシエ
ルモールド用鋳物砂を提供する。
（作用）
本発明者らは、新規な鋳物砂に関して研究する
中で、フエロニツケル製錬時に発生する鉱滓に着
目し、これを珪砂に対し15〜70wt％（以下は単
に「％」で略記する）添加した場合、オリビン砂
と珪砂との混合にかかる従来の鋳物砂と全く同等
の特性を有する鋳物砂が得られることを見い出し
た。すなわち、このフエロニツケル製錬鉱滓は、
MgO、SiO2、Al2O3、FeOおよびCaOの組成が上
記の範囲に制御されると、それの線膨張係数が、
従来使用していた前記オリビン砂と同じように小
さいものとなり、それ故に、注湯時の鋳型割れ防
止に効果を示すのである。
その結果、フエロニツケル製錬鉱滓を骨材とし
た本発明鋳物砂によれば、レジンの種類、添加
量、焼成時間等の条件を何ら変更することなし
に、従来技術の有する問題点をことごとく解決す
ることができることが判り、本発明を完成した。
以下、この知見についてさらに詳しく説明す
る。
本発明者らは、本発明鋳物砂の骨材として、前
記フエロニツケル製錬鉱滓に関して種々研究・実
験を重ねた結果、次のような特性を見出した。
第１表は、かかるフエロニツケル製錬鉱滓とオ
リビン砂の成分組成の一例であり、第２表は鉱
滓、オリビン砂および珪砂の線膨張係数である。
これらの表より本発明鋳物砂の骨材としての鉱滓
はオリビン砂の成分組成と全く異なるが、線膨張
係数はほとんど同じであり、従つて熱膨張率がほ
とんど同じになるという性質を見出した。
(Industrial Application Field) The present invention relates to molding sand used when manufacturing cast products by the shell mold method, and in particular molding sand generated when pouring molten metal into a shell mold and mold sand caused by expansion of the mold. This invention relates to foundry sand for shell molds that can prevent surface carburization, surface roughening, mold cracking, etc. (Prior Art) In shell mold castings, roughening of the surface of the casting and the formation of a carburized layer due to the mold gas caused by the shell mold are harmful, and are particularly responsible for cracking during manufacturing. As a method to prevent roughening and carburization of the casting surface due to mold gas caused by such shell molds,
(1) A method of adding red iron to foundry sand, (2) A method of using a coating material, (3) A method of adding foundry sand such as olivine sand, which has the property of being easily sintered, (4) 1973.3
Month. p19 General Foundry Center: LO shown in examples of casting defects and their countermeasures in organic self-hardening molds
I. Methods based on operational management such as limiting the amount of resin added are known. On the other hand, mold cracking caused by the expansion of the mold that occurs when pouring molten metal into a shell mold is a fatal problem, and methods for preventing cracking include (5) increasing the thickness of the foundry sand in the mold or reducing sand grains and shot. Methods of reinforcing with balls, and (6) adding olivine sand, which has a small coefficient of linear expansion and therefore a small coefficient of thermal expansion, are known. (Problems to be Solved by the Invention) Methods (1) to (4) for preventing surface roughness and carburization of the casting surface caused by the shell mold have the following problems. In other words, the method (1) of adding red iron to the foundry sand has the effect of preventing active gas from being released into the molten metal by reacting with the generated gas, but in order to achieve this effect, It is necessary to make it into a fine powder, and if it is made into a fine powder, the amount of resin added increases accordingly, so it cannot be said to be an effective means.
Although the method of using mold coating material in (2) above can be expected to have a defect prevention effect, it requires the cost of the mold coating material, and
The number of mold application steps increases, which increases manufacturing costs. Said
In the method (3) of mixing foundry sand such as olivine sand, by adding olivine sand, which has the property of sintering easily, to the silica sand, the olivine sand sinteres during pouring and forms a strong film. Therefore, it has the effect of preventing skin roughness and carburization. However, since olivine sand is expensive, the cost increases. On the other hand, a method for preventing mold cracking caused by expansion of the mold that occurs when pouring molten metal into the shell mold (5)
Method (6) has the following problems. That is,
The above-mentioned method (5), such as increasing the sand thickness of the foundry sand in the mold, increases the cost due to the increase in the number of steps required for reinforcing work. In the method (6) of adding olivine sand, etc., the effect of preventing mold cracking during pouring is recognized by using olivine sand with a small coefficient of linear expansion as aggregate, but olivine sand is expensive. Furthermore, due to the grain type of the sand, the amount of resin needs to be increased, which increases costs. An object of the present invention is to provide molding sand that can produce shell mold castings without causing mold cracking during pouring, roughening of the surface of the casting, and carburization, which are the problems of the prior art. (Means for Solving the Problems) As a composition of foundry sand for achieving the above object, the present invention has MgO: 27 to 33 wt%, SiO2 : 48 to 30% by weight.
58wt%, Al2O3 : 1-3wt% , FeO: 5-11wt
%, CaO: 4 to 6 wt%, the balance consisting of unavoidable impurities, and a linear expansion coefficient equivalent to that of olivine sand 15
Provided is foundry sand for shell molds consisting of a mixture of ~17wt% and the balance silica sand. (Function) While researching new foundry sand, the present inventors focused on slag generated during smelting of ferronic sand, and made it 15 to 70 wt% (hereinafter simply abbreviated as "%") to silica sand. It has been found that when added, foundry sand can be obtained that has exactly the same properties as conventional foundry sand made by mixing olivine sand and silica sand. In other words, this Ferronitskel smelting slag is
When the compositions of MgO, SiO 2 , Al 2 O 3 , FeO and CaO are controlled within the above range, their linear expansion coefficients are
It is as small as the previously used olivine sand, and is therefore effective in preventing mold cracking during pouring. As a result, the foundry sand of the present invention using Ferronitskel smelting slag as an aggregate solves all the problems of the prior art without changing conditions such as the type of resin, amount added, firing time, etc. It was found that this could be done, and the present invention was completed. This finding will be explained in more detail below. The inventors of the present invention have conducted various studies and experiments on the ferronite smelting slag as an aggregate for the foundry sand of the present invention, and have discovered the following characteristics. Table 1 shows an example of the composition of the ferronic slag and olivine sand, and Table 2 shows the linear expansion coefficients of the slag, olivine sand, and silica sand.
From these tables, it has been found that although the composition of slag as an aggregate for the foundry sand of the present invention is completely different from that of olivine sand, the coefficient of linear expansion is almost the same, and therefore the coefficient of thermal expansion is almost the same.
【表】【table】
【表】
次に、この製錬鉱滓は、フエロニツケル鉱石の
製錬時に1400℃以上に加熱されるため、イグニツ
シヨンロスが低く、ガス発生量が少ない性質を有
し、しかも、この製錬鉱滓は硬いため、繰り返し
使用しても摩耗が少ないという性質も具備するこ
とが判つた。このような特性から本発明者らは、
実験して次の効果を確認した。
すなわち、(1)珪砂に鉱滓を15〜70％添加する
と、線膨張係数が著しく小さいため、注湯時鋳型
割れ防止に効果がある。(2)珪砂に鉱滓を15〜70％
添加すると、鋳型ガスによる汚染が少ないため、
珪砂にオリビン砂を添加したときと同様浸炭防止
に効果がある。(3)珪砂に鉱滓を15〜70％添加する
ことにより、ガス発生量が少なくなるため、肌荒
れなどのガス欠陥の低減に効果があり、高品質の
鋳物を製造することができる。(4)鉱滓は高価なオ
リビン砂に代わつて安価に使えることから大幅な
コスト低減効果がある。(5)新しい鋳物砂資源とし
ての効果がある。
次に、本発明鋳物砂の骨材としての前記フエロ
ニツケル製錬鉱滓の添加量を限定する理由につい
て説明する。
かかる製錬鉱滓は、前述のように優れた性質を
有するが、耐火度が低いため、鋳込温度が高い鋳
物の場合、大量に添加すると、鋳物表面の肌荒れ
が僅かながら生ずる。従つて、鋳肌に制限がある
場合は、添加量の上限として、例えばステンレス
鋼、鋳鋼、銅およびその合金に対し、鉱滓70％と
することが実験により好適であることを確認し
た。一方、珪砂に対する添加量が15％未満である
と、その効果が充分発揮されなくなるので15％以
上が必要である。
従つて、鉱滓の珪砂に対する添加量が15〜70％
とする必要がある。
（実施例）
材質SUS 13ステンレス鋼からなるボール弁本
体を1580〜1600℃の鋳込み温度でシエルモールド
法により製造した場合の７種類の鋳型条件を第３
表に示す。
なお、鋳型を製造する際、鉱滓のAFS粒度指
数は通常の60〜150の範囲のものを用いた。
また、鋳型の製造方法は従来方法と同一とし
た。[Table] Next, this smelting slag is heated to over 1400℃ during the smelting of ferronitskel ore, so it has the properties of low ignition loss and low gas generation. It was found that because it is hard, it also has the property of having little wear even after repeated use. Based on these characteristics, the present inventors
We conducted an experiment and confirmed the following effects. That is, (1) adding 15 to 70% of slag to silica sand has a significantly small coefficient of linear expansion, which is effective in preventing mold cracking during pouring. (2) 15-70% slag added to silica sand
When added, there is less contamination from mold gas,
It is effective in preventing carburization, similar to when olivine sand is added to silica sand. (3) By adding 15 to 70% of slag to silica sand, the amount of gas generated is reduced, which is effective in reducing gas defects such as surface roughness, and enables the production of high-quality castings. (4) Mine slag can be used inexpensively in place of expensive olivine sand, resulting in a significant cost reduction effect. (5) It is effective as a new foundry sand resource. Next, the reason for limiting the amount of the ferronic smelting slag added as the aggregate of the foundry sand of the present invention will be explained. Although such smelting slag has excellent properties as described above, it has low refractory properties, so if it is added in large quantities to a casting whose casting temperature is high, the surface of the casting will be slightly roughened. Therefore, when there is a restriction on the casting surface, it has been confirmed through experiments that the upper limit of the addition amount is, for example, 70% slag for stainless steel, cast steel, copper, and their alloys. On the other hand, if the amount added to the silica sand is less than 15%, the effect will not be sufficiently exhibited, so it is necessary to add 15% or more. Therefore, the amount of slag added to silica sand is 15 to 70%.
It is necessary to do so. (Example) Seven types of mold conditions when a ball valve body made of SUS 13 stainless steel is manufactured by the shell molding method at a casting temperature of 1580 to 1600°C are shown in the third example.
Shown in the table. In addition, when manufacturing the mold, the AFS particle size index of the slag used was in the normal range of 60 to 150. Furthermore, the mold manufacturing method was the same as the conventional method.
【表】【table】
【表】
第３表より、試料No.１〜No.３は、本発明例で、
珪砂70％、50％、30％に、フエロニツケル製錬鉱
滓をそれぞれ30％、50％、70％を添加してなる鋳
物砂に対し、さらに粘結成分として外枠量で３〜
４％のレジンを添加してシエルモールド用成形材
料としたものである。No.４、No.５は比較例でNo.４
は珪砂90％に鉱滓10％を添加し、No.５は鉱滓100
％を鋳物砂としてレジン３〜４％を添加したもの
である。No.６、No.７は従来例で、No.６は珪砂70％
にオリビン砂30％を添加しNo.７は珪砂100％を鋳
物砂として、レジン３〜４％を添加したものであ
る。
第４表は、上記各試料（鋳物砂）について、シ
エルモールド法によりボール弁を鋳造したとき
の、鋳型の型割れ、ボール弁肉厚交差部に生じる
鋳型ガスを起因とする鋳肌荒れおよびガスホール
発生の有無、浸炭層の様子についての結果をまと
めたものである。
なお、上記鋳型割れについては、割れが全く発
生しない場合を〇印、割れがやや発生した場合を
△印、鋳型の10％以上の鋳型に割れが発生した場
合を×印で示す。この第４表に示す結果から判る
ように、本発明例は比較例および従来例に比べて
同等またはそれ以上である。
また、鋳肌荒れについては、荒れが全く認めら
れない場合を◎印、肉厚交差部のみに発生する場
合を〇印、肉厚交差部の他にフランジ部および胴
体部の一部に発生する場合を△印、全面に発生す
る場合を×印で示す。本発明例はオリビン砂を用
いた鋳物砂の場合と同等であり、その他の比較例
および従来例に比べて優れている。
また、ガスホール発生量については、発生量が
非常に少ない場合を〇印、発生量がやや多い場合
を△印で示す。本発明例は比較例および従来例に
比べてガス発生量は同じかまたはより少ないこと
がわかる。
そして、浸炭層については、浸炭層が存在しな
い場合を〇印、浸炭層が一部存在する場合を△印
で示す。本発明例は比較例および従来例に比べて
浸炭層の存在は同じかまたはより少ないことがわ
かる。[Table] From Table 3, samples No. 1 to No. 3 are examples of the present invention,
Foundry sand made by adding 70%, 50%, and 30% silica sand and 30%, 50%, and 70% Ferronitskel smelting slag, respectively, and an additional amount of 3 to 30% of the outer frame amount as a viscous component.
This is a molding material for shell molds with the addition of 4% resin. No. 4 and No. 5 are comparative examples.
10% slag is added to 90% silica sand, and No. 5 is 100% slag.
% of foundry sand and 3 to 4% of resin is added. No. 6 and No. 7 are conventional examples, and No. 6 is 70% silica sand.
30% olivine sand was added to No. 7, and No. 7 was made of 100% silica sand as foundry sand with 3 to 4% resin added. Table 4 shows the cracks in the mold, the roughness of the casting surface caused by the mold gas that occurs at the intersection of the ball valve wall thickness, and the gas holes when ball valves are cast using the shell mold method for each of the above samples (foundry sand). This is a summary of the results regarding the presence or absence of carburization and the condition of the carburized layer. Regarding mold cracking, the case where no cracking occurs is indicated by ◯, the case where some cracking occurs is indicated by △, and the case where cracks occur in 10% or more of the molds is indicated by ×. As can be seen from the results shown in Table 4, the examples of the present invention are equivalent to or better than the comparative examples and the conventional examples. Regarding casting surface roughness, if no roughness is observed at all, mark ◎; if it occurs only at the wall thickness intersection, mark ○; if it occurs at the flange or part of the body in addition to the wall thickness intersection. The case where the problem occurs is shown with a △ mark, and the case where it occurs on the entire surface is shown with an × mark. The present invention example is equivalent to the case of foundry sand using olivine sand, and is superior to other comparative examples and conventional examples. Regarding the amount of gas holes generated, cases in which the amount of gas holes generated is very small are indicated by ◯, and cases in which the amount generated is somewhat large are indicated by △. It can be seen that the amount of gas generated in the example of the present invention is the same or smaller than that of the comparative example and the conventional example. Regarding the carburized layer, the case where the carburized layer does not exist is indicated by ◯, and the case where a part of the carburized layer exists is indicated by △. It can be seen that the presence of carburized layers in the present invention example is the same or less than that of the comparative example and the conventional example.
【表】
次に、第１図〜第３図は第３表の鋳型条件でシ
エルモールド法により製造したボール弁本体のフ
ランジ部押湯裏側表面層の浸炭層組織の顕微鏡写
真（倍率100倍）を示す。
第１図は試料No.１の場合で珪砂70％、鉱滓30
％、第２図は試料No.６の場合で珪砂70％、オリビ
ン砂30％、第３図は試料No.７の場合で珪砂100％
であるが第１図および第２図から明らかなように
浸炭層はまつたくみられないが、第３図では深さ
0.3mmの浸炭層がみられる。
（発明の効果）
本発明により下記の効果が得られた。
(1)珪砂に本発明鋳物砂の骨材としての鉱滓を15
〜70％添加すると、線膨張係数が著しく小さいた
め、注湯時の鋳型割れ防止に効果がある。(2)珪砂
にこの鉱滓を15〜70％添加すると、鋳型ガスによ
る汚染が少ないため、珪砂にオリビン砂を添加し
たときと同様浸炭防止に効果がある。(3)珪砂にこ
の鉱滓を15〜70％添加することにより、ガス発生
量が少なくなるため、肌荒れなどのガス欠陥の低
減に効果があり、高品質の鋳物を製造することが
できる。(4)鉱滓は高価なオリビン砂に代わつて安
価に使えることから大幅なコスト低減効果があ
る。(5)鋳物砂として新しい砂資源としての効果が
ある。[Table] Next, Figures 1 to 3 are micrographs (100x magnification) of the carburized layer structure of the surface layer on the back side of the riser at the flange of the ball valve body manufactured by the shell molding method under the mold conditions shown in Table 3. shows. Figure 1 shows sample No. 1 with 70% silica sand and 30% slag.
%, Figure 2 shows sample No. 6 with 70% silica sand and 30% olivine sand, Figure 3 shows sample No. 7 with 100% silica sand.
However, as is clear from Figures 1 and 2, the carburized layer is not visible at all, but in Figure 3, the depth
A 0.3mm carburized layer is observed. (Effects of the Invention) The following effects were obtained by the present invention. (1) Add 15 slags to silica sand as the aggregate of the foundry sand of the present invention.
When ~70% is added, the coefficient of linear expansion is extremely small, which is effective in preventing mold cracking during pouring. (2) When 15 to 70% of this slag is added to silica sand, there is less contamination by mold gas, so it is as effective in preventing carburization as when olivine sand is added to silica sand. (3) By adding 15 to 70% of this slag to silica sand, the amount of gas generated is reduced, which is effective in reducing gas defects such as surface roughness, and high quality castings can be manufactured. (4) Mine slag can be used inexpensively in place of expensive olivine sand, resulting in a significant cost reduction effect. (5) It is effective as a new sand resource as foundry sand.
第１図〜第３図はそれぞれシエルモールド法に
より製造したボール弁本体のフランジ部押湯裏側
表面層の金属組織を示す顕微鏡写真（倍率100倍）
である。
Figures 1 to 3 are micrographs (100x magnification) showing the metal structure of the surface layer on the back side of the feeder at the flange of the ball valve body manufactured by the shell molding method.
It is.
Claims (1)
Al2O3：１〜3wt％、FeO：５〜11wt％、CaO：
４〜6wt％、残部不可避的不純物からなる成分組
成を有して、線膨張係数がオリビン砂相当のもの
である、フエロニツケル鉱石製錬鉱滓15〜70wt
％と、残部珪砂との混合物からなるシエルモール
ド用鋳物砂。1 MgO: 27-33wt%, SiO2 : 48-58wt%,
Al2O3 : 1-3wt% , FeO: 5-11wt%, CaO:
15-70wt of ferronite ore smelting slag having a composition of 4-6wt%, the remainder being unavoidable impurities, and a linear expansion coefficient equivalent to that of olivine sand.
% and the balance is silica sand.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10487586A JPS62263842A (en) | 1986-05-09 | 1986-05-09 | Molding sand for shell mold |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10487586A JPS62263842A (en) | 1986-05-09 | 1986-05-09 | Molding sand for shell mold |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62263842A JPS62263842A (en) | 1987-11-16 |
| JPH0346211B2 true JPH0346211B2 (en) | 1991-07-15 |
Family
ID=14392378
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10487586A Granted JPS62263842A (en) | 1986-05-09 | 1986-05-09 | Molding sand for shell mold |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62263842A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH069726B2 (en) * | 1987-12-02 | 1994-02-09 | 山川産業株式会社 | Resin coated sand |
| CN109158525A (en) * | 2018-10-19 | 2019-01-08 | 含山县兴达球墨铸铁厂 | A kind of moulding sand for casting formula |
-
1986
- 1986-05-09 JP JP10487586A patent/JPS62263842A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62263842A (en) | 1987-11-16 |
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