Showing papers in "Tetsu To Hagane-journal of The Iron and Steel Institute of Japan in 1980"
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TL;DR: In this article, the authors seek the possibility of the separate recovery of iron and phosphorus from BOF slags using a plasma furnace under the conditions that the slags were reduced by carbon powder in coexistance of Fe-Si alloy bath where silicon presumably enhances the activity of phosphorus.
Abstract: Shuji TAKEUCHI, Nobuo SANO, and Yukio MATSUSHITA Synopsis: The recovery of iron from BOF slags by reduction is one of the most effective ways of its utilization. However, phosphorus which is simultaneously reduced dissolves in liquid iron almost completely. The present work was undertaken to seek the possibility of the separate recovery of iron and phosphorus from BOF slags. The experiments were carried out using a plasma furnace under the conditions that BOF slags were reduced by carbon powder in coexistance of Fe-Si alloy bath where silicon presumably enhances the activity of phosphorus. More than 95% of iron and phosphorus were removed from the slags. While iron was recovered by Fe-Si alloy, the substantial amount of reduced phosphorus was removed to gas phase as P2 gas. It is likely to be CO gas explosively generated on the reduction of iron oxide in slag that has great effect on the gaseous dephosphorization.
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TL;DR: In this paper, the vapor pressure of P and P2 above Fe-P alloys has been determined by a newly developed experimental method, and the standard free energy changes of the reactions for liquid FeP alloy system were calculated from these vapor pressures.
Abstract: The vapor pressures of phosphorus gases, P and P2, above Fe-P alloys have been determined by a newly developed experimental method. In this experimental method, phosphorus in the deposit film obtained by the Knudsen effusion method with collection technique was determined by a secondary ion mass spectrometer. The vapor pressures of P and P2 have been obtained from these determined values and the ratio of the ion currents of P+ to those of P+2 which had been obtained by the ordinary Knudsen cell-mass spectrometer combination. The standard free energy changes of the reactions for liquid Fe-P alloy system were calculated from these vapor pressures, and the following values have been obtained.P(g)=P(wt%)ΔG°=-95.3+1.55×10-2T(±2.2)(kcal/mol)1/2P2(g)=P(wt%)ΔG°=-37.7+0.13×10-2T(±1.1)(kcal/mol)P(g)=1/2P2(g)ΔG°=-57.6+1.42×10-2T(±1.1)(kcal/mol)(1-3wt% P, 1590-1650°C)
19 citations
19 citations
TL;DR: In this paper, the effect of austenite grain size on the hardenability of eutectoid steel is examined and the obtained results were analyzed according to the Cahn's theory and the volume fraction of pear-
Abstract: Synopsis: As a first step to obtain a theoretical prediction of hardenability based upon the theories of phase transformation, the effect of austenite grain size on the hardenability of eutectoid steel is examined. The effect of austenite grain size on the isothermal pearlite transformation curves were first measured. The obtained results were analysed according to the Cahn's theory and the volume fraction of pear-
16 citations
TL;DR: In this paper, a new tempering parameter (ƒ-value) was defined basing on Arrhenius' equation so as to express the degree of tempering and to maintain the equivalence of time and temperature over a wide range of temperings conditions.
Abstract: Synopsis: A new tempering parameter (ƒÉ-value) has been defined basing on Arrhenius' equation so as to express the degree of tempering and to maintain the equivalence of time and temperature over a wide range of tempering conditions. Activation energy of the tempering process governing the changes in such mechanical properities as tensile and yield strength and hardness was determined by using a plain carbon steel and low alloy steels containing manganese, chromium and molybdenum. The activation energies obtained were to be 70 kcal/ mol (295 kJ/mol) in carbon steel and about 100 kcal/mol (420 kJ/mol) in Cr-Mo steel, increasing with alloy contents. Using these activation energies, mechanical properties of tempered steel can be approximately expressed as a function of ƒÉ-value in a linear fashion for any combination of temperature and time, ranging from 400 ° c to 700 •Ž and from 0.01 h to 1 000 h, respectively. In addition, making use of the parameter, an analytical method of tempering effect is applied to a practical heat program by summarization of the tempering effects of two individual processes or integration of the tempering effect over a whole process of heat cylce in which temperature steadily changes. Predicted mechanical properties by this method were in good accordance with observed values.
TL;DR: In this paper, alloying and inoculation were tested to improve the solidification structure of type 430 steel, and they found that among used alloying elements, Ti is most effective for formation of equiaxed zone, and this effect is attributed to TiN as nuclei.
Abstract: Synopsis: In order to improve the solidification structure of type 430 steel, alloying and inoculation were tested. Among used alloying elements, Ti is most effective for formation of equiaxed zone, and this effect is considered to be attributed to TiN as nuclei. Ratio of equiaxed zone is related to quantity of TiN. Co-borate and other borates induce the local temperature drop by thermal decomposition in liquid steel, and then improve the solidification structure. So these inoculators must be used at casting stage.
TL;DR: In this article, the corrosion resistance of Zn-Co based Co-electrogalvanized steel sheet has been investigated, and the effect of the additional elements (Co and Mo) containing in deposit on the corrosion behavior has been considered.
Abstract: Synopsis: The corrosion resistance of Zn-Co based Co-electrogalvanized steel sheet has been investigated, and the effect of the additional elements (Co and Mo) containing in deposit on the corrosion behavior has been considered. ( 1 ) Zn-Co-Mo plating is proved to withstand about 4 to 6 times longer, in the occurrence of red rust by salt spray test, than Zn plating, and has an excellent resistance against the deterioration of PVC adhesion under salt spray test. ( 2 ) After the salt spray test, the corrosion potential of Zn-Co-Mo plating moves slowly to the Fe. On the other hand, that of Zn plating moves rapidly to the Fe potential. Thoughthe initial corrosion current of Zn-Co-Mo plating is larger than that of Zn plating, the corrosion current of Zn-Co-Mo plating tends to be reduced with the corrosion progress, and it becomes smaller than Zn plating after all. The cathodic reaction of Fe exposed by the dissolution of Zn andthe anodic reaction of Zn are controlled by the corrosion products containing the composite compounds of basic cobalt chloride and Mo (OH)3, so that the corrosion of Fe and the occurrence of red rust is restrained. Also, the corrosion resistance of PVC coating on Zn-Co-Mo plating steel sheet is superior to that on Zn plating steel sheet.
TL;DR: In this paper, the authors present an approach to deal with the problem of gender discrimination in the context of gender-based bullying in the workplace, where gender identity is not considered.
Abstract: で 開発 され た 方 法 も広 く利 用 され て い る. 上記,塩 浴及び ガス軟窒化法 は,い ずれ も570°C 付 近の低 温処理 で,処 理に さい し,窒 素 と炭 素を同時 に鋼 の表面か ら内部に拡散 させ て窒化す るので,NH3の み による純 窒化法 と区別 して軟窒化法 と称す る.軟 窒化法 は,炭 素鋼をは じめ各種 の合金鋼,鋳 鉄に利用 できる特 徴を有す る。 一方,NH3に よる純窒化 法は窒化効率が悪 い た めに 処理時 間が50~100hを 要 し,窒 化物層 が脆 く,AI, Gr な どを含 む合金鋼 のみ に適用 され るので,こ の欠点を補 うため最近,イ オ ソ窒化法6)~8)が西 ドイ ツのKIcickner Ionon GobHで 企 業化 され,わ が国で も10数 年前か ら 実用化 され,目 ざま しい発展を とげ つつあ る.こ の方法 はN2,H2ガ スを真空 中で グ ロウ放電す る ことに よつ て 生ず るN+,H+イ オ ンの処理部 品の表 面へ の衝撃 に よ つて加熱窒化す る方 法で無公害 で,窒 化速度が大 きい. 以下,鋼 の窒化 について,(1)各 種 窒化法 の概要 と窒 化 反応,(2)窒 化 に必要な基礎知織,(3)塩 浴及 び ガス 軟 窒化に よる鋼 の諸性質,(4)イ オ ン窒化 の特徴,(5) 窒 化 と他 の熱処理 を組 み合わせ た複合熱処理,(6)新 し い窒化用鋼 の概要 な どにつ いて述 べ,窒 化設備,操 作, 公 害対策 な どについては紙面 の関係 で省略す る. 最近,関 心が高まつてきた各種窒化法を有効に活用す るため の参 考になれば幸 いであ る。
TL;DR: In this article, the effects of heating and cooling rates during phase transformation and specimen thickness on the transformation texture have been studied by using an extra low carbon sheet steel with the initial texture of {111}.
Abstract: For the purpose of investigating the formation mechanism of the texture which is developed by ferrite (α)→austenite (γ)→ferrite (α) transformation, the effects of heating and cooling rates during phase transformation and specimen thickness on the transformation texture have been studied by using an extra low carbon sheet steel with the initial texture of {111}.The results obtained are summarized in the following:(1) A weak {100} and {111} texture was formed in the surface layer of the specimen transformed by rapid heating and rapid cooling.(2) By rapid heating and subsequent slow cooling, a texture with {110} orientations and orientations 20-30 deg shifted away from {100} was obtained in the surface layer.(3) Slow heating and slow cooling produced a distinct {100} texture in the surface layer.(4) There was a marked difference in texture between surface and midsection of thick specimen: In the midsection, the texture similar to that described in (1) was formed, independent of the heating and cooling rates. While, the specimen surface exhibited the texture as mentioned in (1) to (3) on each condition.(5) Those results were consistently explained on the assumptions that the orientation relationship between bcc and fcc follows the Kurdjumov-Sachs relation, and that during a slow progress of α→γ→α transformation the orientation change proceeds preferentially by operation of such variants that generate a larger elastic work in the normal direction of a sheet surface.
TL;DR: In this article, a mathematical model for predicting the temperature field in the continuous casting mold is developed by taking account of the properties of casting powder, and the heat flux in the mold calculated with the aid of this model is found to be similar to the observed result except in the vicinity of the meniscus and at the lower part of the mold.
Abstract: Synopsis: Mathematical model for predicting the temperature field in the continuous casting mold is developed by taking account of the properties of casting powder. Heat flux in the mold calculated with the aid of this model is found to be similar to the observed result except in the vicinity of the meniscus and at the lower part of the mold. Calculated values of the average heat flux are in good agreement with the data observed at the various withdrawal speeds ranging from 0.8 to 1.5 m/min and by use of the various kinds of powder.
TL;DR: In this paper, the melting properties of MgO containing sinter during reduction were investigated and the results obtained are summarized as follows: (1) The formation of high viscosity silicate and magnetite prevents the homogenization of slag and therefore, Cr slags and Ni slag remain unslagged.
Abstract: The solution property of MgO containing materials into the CaO-Fe2O3 system and the melting property of MgO containing sinter during reduction were investigated. The results obtained are summarized as follows:(1) The formation of high viscosity silicate and magnetite prevents the homogenization of slag and therefore, Cr slag and Ni slag remain unslagged. The formation of dicalcium ferrite prevents the dissolution of periclase into the CaO-Fe2O3 system.(2) During reduction unslagged MgO makes the shell of MgO-FeO solid solution with FeO in glassy silicate and its solution is negligibly low.(3) For both normal sinter and pellet, all silicate minerals dissolve above about 1240°C.(4) MgO addition in sinter is effective to decrease the slag quantity during reduction but the melting property of sinter is not so improved as that of pellet. The proper basicity for sinter and pellet is about 1.4.
TL;DR: In this article, a simulation by plasticine is carried out to estimate the stress distribution and deformation of steel in hot rolling and to prevent the generation of internal or surface crack of slab in continuous casting.
Abstract: Simulation by plasticine is carried out to estimate the stress distribution and deformation o f steel in hot rolling and to prevent the generation of internal or surface crack of slab in continuous casting.In this report, first of all, the following dynamic properties of plasticine is treated to establish the foundation of simulation:i) Static properties (the stress-strain relation, its dependence on temperature and a criterion of yielding, etc.)ii) Kinetic properties (the dependence of stress on the strain-rate etc.)iii) Friction with metal surface.From the above investigation, it became clear that, there exists the following relation between the stress σ(kgf/cm2), logarithmic strain e, strain-rate e(1/s) and temperature T(°K), in the region of T=253°-323°K, e=0.02-0.3 and e=10-2-100l/s; σ=1.15×10-5e0.085e0.12 exp(3530/T)Then the above result is compared with the deformation resistance of steel at high temperatures (about 1000°C). And it is confirmed that plasticine has well satisfied properties to simulate not only the deformation of steel at high temperatures but also the stress distribution.
TL;DR: In this paper, the formation mechanism of MnS-type inclusion in steel was investigated on the basis of the experimental results with the effects of sulfur content and cooling rate on the morphology of sulfide, the relation between the solidification structure and the distribution of sulfides, and the observation of formation process in steel quenched from various temperatures.
Abstract: Synopsis: The formation mechanism of MnS-type inclusion in steel was investigated on the basis of the experimental results with the effects of sulfur content and cooling rate on the morphology of sulfide, the relation between the solidification structure and the distribution of sulfides, and the observation of formation process of sulfide in steel quenched from various temperatures. As the result, it became clear that the sulfide which formed an eutectic colony (type II according to Sims' classification) was increased with the sulfur content in steel and the cooling rate, observed mostly in the region solidified lastly and formed in contact with the melt at the final period of solidification, and also that the non-colony type sulfide (type I, type III and so on) was hardly affected with the sulfur content in steel, decreased as an increase of cooling rate, observed mainly around a dendrite and increased remarkably after the finish of solidification. These results can be explained rationally by an idea that the colony type sulfide is formed by the eutectic reaction while the non-colony type sulfide is formed as the precipitate from the solid steel.
TL;DR: In this paper, the authors discuss the importance of the role of the environment in the development of the Internet and its role in the future. But they do not discuss the impact on the current state of the internet.
Abstract: 高温におけ る金属材料 の強度 は,材 料 に作用す る荷重 お よび温度 の状態に よつ て異 なる様相 を示す ので,異 な る現象名で区別 され ているのが普通 である。図1は, 静 的荷重,動 的荷重 お よび温度変動 に対応 して機 械的な平 均応力 σm,応 力振 幅 σaお よび熱応 力 σTを 選 び,こ れ ら3者 の組 み合せに よつて分類 した高温強度を示 してい る.(1)は\"ク リープ\",(1)'は\"引 張 り\",(1)\"は\"リ ラ クセ ー ション\"で あつ て,そ れ ぞれ応 力 σmに 一定,増 加, 減 少 とい う相違が あるが,い ずれ も一方 向単 調 クリープ変 形 が生 じるとい う点で共通 している.こ れ に対 して(2)お よび(2)'は 一定応 力 σmの上 に変動応 力 σaが重畳 した \"繰 り返 し応力 ク リープ\"で あつて,こ の うち(2)は繰 し返