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26 巻, 3 号
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研究論文
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—硫黄製鍊におけるポット内ガスに因る鑄鐵の腐蝕—丸山 益輝1954 年 26 巻 3 号 p. 127-132
発行日: 1954/03/25
公開日: 2012/11/14
ジャーナル フリーTo obtain an accurate knowledge on the corrosion reaction of a cast iron pot in smelting sulphur, the composition change of a gas in the pot and the structure and composition of scale of the pot were firstly investigated. The corrosion of the pot progressed in three stages. The first was the oxidizing and sulphidizing period in which H2O, H2S and SO2 acted a main role to dry corrosion of the cast iron pot, the second the sulphidizing period in which the corrosion of the pet was mainly progressed by sulphur vapor, and the third the oxidizing period in which the corrosion by oxygen gas was remarkable. Scale was divided into three main layers, that is, the outer, middle and inner layers. Although these layers were different in the structure and the composition, every one mainly consisted of FeS and a little iron oxide, and the sulphur contents of them were a few percentage lower than that of pure FeS. From this fact, it was more cleared that the corrosion of the pot progressed in the complexity of the oxidation and the sulphuration. Nextly, the corrosion resistance of Al-Cr and Al-Mo alloy cast irons for the gas in the pot was investigated. These alloy cast irons showed twice or thrice the corrosion resistance of plain cast iron in pure sulphur vapor, while, in the pot gas, these alloy irons did not show such an excellent corrosion resistance. Consequently, it is presumed that the complexity of the oxidation and the sulphuration may destroy the scale layer of alloying elements and accelerate the corrosion.抄録全体を表示PDF形式でダウンロード (966K) -
金田 義夫1954 年 26 巻 3 号 p. 132-139
発行日: 1954/03/25
公開日: 2012/11/14
ジャーナル フリーJapanese foundries, nowadays, have the tendency to adopt the green sand casting widely, In the cases of the heavy and the specific casting, the dry sand casting still keeps the main current. In the latter case, it is conceivable that free water contained in the mould will produce blows or cavities in the casting. Experiments have been conducted on the matter, not merely at the laboratory but also at the foundry by inserting thermocouples into the mould. The findings are: 1) The condition of free water distribution in the mould has been clarified by the state of thermal distribution therein. Practically, the temperature gradient of the mould can be regarded to be linear. If the mould is perfectly dried, the temperature rises rapidly, and the gradient becomes smaller. 2) When the sand used is much permeable, the time required for drying does not deffer according to the degrees of the drying temperature, but when the permeability is small it takes longer. 3) The remaining amount of water in the mould is proportionate to the maximum gas pressure produced at the time of tapping. If the pressure is high, the casting defects such as blows, rough surface, etc. are caused. 4) Certain moulds take several days in setting the core and so checking was made about the change of the amount of water in the mould to be caused during the core setting. The findings are: i) As clay is well absorptive, it sucks up moisture during that time, tut the moisture can be removed by heating it at 100°C∼120°C. ii) In an ill dried mould, the undried part spreads once at a low he ting but it diminishes in a certain lapse of time. In the case of the high temperature, the moist part always diminishes without spreading. iii) While the mould temperature is still high immediatly after drying, the permeability is smaller than that after cooling.抄録全体を表示PDF形式でダウンロード (973K) -
前川 靜彌, 秋本 宏1954 年 26 巻 3 号 p. 140-146
発行日: 1954/03/25
公開日: 2012/11/14
ジャーナル フリーA core that is surrounded by molten steel usually changes its volume by expansion of sand grains, and then it collapses after the bond is destroyed, by the heat. Therefore if a core collapses too rapidly, core sand may be included in the casting, and if a core callapses too slowly, the casting may exhibit hot tears. This collapsing velocity may be changed by the sand grain distribution, the kind of the binder, the clay content of the core mixture, etc. We have studied on collapsibility of core sand at the high temperature at which various binders are combined. The results obtained are as follows. (1) The collapsing time of the core usually increases according to the increase of the sand grain index number, stamping number of core sand, the binder content, etc. (2) Under the same conditions, the collapsing time of cores of crystalline or angular sand grains is shorter than that of sub-angular sand grains. (3) The collapsing time of bentonite-combined-sands is shorter than that of clay-com-bined-sands. The collapsing time of clay-combined-sand is usually reduced in accordance with the increase of the clay and colloidal contents in the clay minerals. (4) The collapsing time is increased by addition of the organic binders, but the addition of iron oxide to the core mixture considerably reduces the collapsing time.抄録全体を表示PDF形式でダウンロード (907K) -
谷村 凞, 谷村 洪一1954 年 26 巻 3 号 p. 146-151
発行日: 1954/03/25
公開日: 2012/11/14
ジャーナル フリーDust sand, collected from the sand preparation plant of a foundry was mixed in various proportions to synthetic sands, which were prepared from silica sand grain and Kibushi-clay. Permeability, flowability and mechanical properties of sands both in wet and dry states were examined. It was shown that permeability of sand decreases with the increasing amount of fine dust ; flowability decreases clearly with fine dust. The effects of fine dust on the strengths of green sand and dry sand are not the same. It is also different according to the test method. In the case of green sand, the more the fine sand the higher the compressive strength. In dry sand, up to 3% addition of fine dust increases the compressive strength ; over that amount, it decreases rapidly. The green bond strength tested by the Doty method, does not increase with the addition of fine dust, as in the case of the compression test ; it decreases slightly with the high content of fine dust. The relation of the transverse strength of dry sand to the various amount of fine sand is similar to that of the compressive strength of dry sand.抄録全体を表示PDF形式でダウンロード (818K) -
望月 博志1954 年 26 巻 3 号 p. 152-157
発行日: 1954/03/25
公開日: 2012/11/14
ジャーナル フリーThe results of the experiment to find the condition under which we get the best camlachie cramp operation in the practice are as follows : 1. The state of occurence of blow holes by the macro-observation. The best surface treatment of camlachie-cramped bars is their complete polishing. 2. The relations between the volume ratio and welding state by the microscope-observation are as follows : The test pieces are completely welded under the next volume ratioes. (i) In case of cast iron at the casting temperature 1370°C. Less than 11.4% in the dry sand mold. Less than 4.6% in the green sand mold. (ii) In case of a steel casting at the casting temperature 1500°C. Less than 21.3% 3. Extraction Test. The test pieces were cut off under the following volume ratioes: Less than 4% in case of the dry sand mold. Less than 2.3% in case of the green sand mold. 4. Comparison by the tensile strength. The increase of the tensile strengh by this operation is 14% or 15% as compared with cast iron without the camlachie cramp.抄録全体を表示PDF形式でダウンロード (913K)
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