巻号一覧
63 巻, 4 号
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飛田 守孝, 植木 太, 山田 廣志1992 年 63 巻 4 号 p. 249-258
発行日: 1992/10/15
公開日: 2009/05/25
ジャーナル フリーIt is well known that molybdenum (Mo) shows recrystallization embrittlement around room temperature after it is exposed for a long period at elevated temperature. This phenomenon is considered to be caused by the weak grain boundary compared with the strong matrix. We tried to use the both elements, B (∼0.44at%) or/and Re (∼1.0at%), in order to strengthen the grain boundary and to decrease the flow stress of the matrix, respectively. The remarkable results are as follows. 1) The most ductile state is attained by heating Mo just above the recrystallization temperature (1173K), not heating to the recovery one. 2) The recrystallized Mo alloys with fine grain size and strong grain boundary are obtained by the addition of B, but the ones recrystallized above 1623K give rise to an abrupt decrease in ductility. It shows that the structure, not size, of grain boundary determines the ductility of Mo alloys. 3) Rhenium brings about a so-called solute softening, and a little addition of Re with B will be able to realize high ductility of the Mo alloy recrystallized at the elevated temperature over 1773K.抄録全体を表示PDF形式でダウンロード (9244K) -
加藤 哲男, 尾畑 智光, 永江 秀樹, 水野 正志, 小島 勝洋1992 年 63 巻 4 号 p. 259-267
発行日: 1992/10/15
公開日: 2009/05/25
ジャーナル フリーOn the automatic magnetic measurement of magnetic soft iron by ring specimen, a change arises in the shape of hysteresis curve according to the change of measurering speed. And a phenomenon is observed as that the more measurering speed causes the more coercive force. The study was performed on the base of magnetic measurement by means of changing in thickness of specimens and these conditions of heat treatment, on the purpose of making clear about the actual state and the origin of that phenomenon. It was cleared that the phenomenon was originated with the delay of magnetization. And this can be explained owing to a view point of the penetration depth of magnetizing, that is depending on the frequency converted from speed of magnetizing and the permeability of materials.抄録全体を表示PDF形式でダウンロード (370K) -
小野 政幸, 内田 満秋, 石橋 忠也1992 年 63 巻 4 号 p. 268-276
発行日: 1992/10/15
公開日: 2009/05/25
ジャーナル フリーAn innovative technology of stainless steel pickling by fixed concentration HF/HNO3 mixtures through diffusion dialysis acid reclamation has been developed and put into practical operation by Daido Steel collaborated with UNITIKA. The system is composed of main parts.
1. Automated analyzing controllers of HF, HNO3 and dissolved metal.
2. Diffusion dialysis cells utilizing ion-selective membranes.
3. Acid replenishment apparatuses.
The system was installed in July, 1989 in 12000t/month capacity pickling line at Hoshizaki Work of Daido Steel. It has been in operation successfully, and has shown effective as follows.
1. Short lead-time and less inventory
300 series and 400 series stainless steel used to be pickled in different chances, but now they can be pickled at any time.
2. Stable quality control
Fixed concentrations leads to good reproductivity in descaling.
3. Reduction by half of the acid cost
The ion-selective membrane allows retrieving the acids from the waste acids.
4. Ecological conservation
The reclamation of acids reduces waste generation by half.抄録全体を表示PDF形式でダウンロード (2078K) -
藤根 道彦, 田辺 哲朗, 秋場 真人, 荒木 政則, 久保田 雄輔, 宮原 昭1992 年 63 巻 4 号 p. 277-285
発行日: 1992/10/15
公開日: 2009/05/25
ジャーナル フリーHigh heat load tests of newly developed electron-beam-melted Mo and W (EB-Mo and EB-W) have been carried out to examine whether these Mo and W are applicable as the candidates of the plasma facing materials in a nuclear fusion reactor. The materials used were single crystal and wrought one of EB-Mo and W and also sintered P/M-Mo and W. The apparatuses used were H+ plasma beam stands in JAERI and NIFS, and an electron beam stand in JAERI. The heat loads tested were 150-1000MW/m2 for 5∼250msec.
The test pieces of these materials irradiated were observed by using an optical microscope and a SEM to examine their macro-and micro-structure.
It was found that single crystals of EB-Mo and W have little effects of high heat load on their structure except for their surface thin layer. It seemed that the irradiated surfaces were melted slightly, but the changes of the microstructure were not recognized from their macro-and micro-structures of cross section.
The irradiated regions of the wrought EB-Mo and W were recrystallized as similar to those of P/M-Mo and W. It seemed that the crystal grain becomes coarse as compared with those of P/M-Mo and W. These phenomena will be explained by the fact that EB-Mo and W used are highly purified and therefore their recrystallized temperatures become low.
As the results, it can be considered that single crystals of EB-Mo and W are applicable as the candidates of the plasma facing materials.抄録全体を表示PDF形式でダウンロード (3205K) -
山田 博之, 吉田 浩二, 大津賀 伝次郎, 西村 司1992 年 63 巻 4 号 p. 286-296
発行日: 1992/10/15
公開日: 2009/05/25
ジャーナル フリーA PPC (Plasma Progressive Casting) furnace with a water cooled mould and plural plasma torches was constructed to melt titanium and its alloys. Ingots of titanium and its alloys have been satisfactorily produced and satisfied chemical compositions and mechanical properties required for VAR double melted ingot.
This process has a distinctive advantage of efficient utilization of titanium and titanium alloys scrap.抄録全体を表示PDF形式でダウンロード (1465K) -
鈴木 昭弘, 飯久保 知人1992 年 63 巻 4 号 p. 297-302
発行日: 1992/10/15
公開日: 2009/05/25
ジャーナル フリーThe Ti-17 alloy has been adopted for advanced jet engine's fans and compressor parts, because it has a better combination of strength and toughness. However, the mechanical properties of the alloy depends strongly on process history and heat treatment condition. To improve the strength of Ti-17 alloy, the authors investigated the effect of thermomechanical treatment on mechanical properties of the alloy.
Beta solution treatment brings in the precipitation of alpha phase at grain boundaries and then decreases ductility and fatigue strength.
Directly aged materials, skipping solution treatment, show very good strength and fatigue endurance limit. At peak aging condition, 0.2% proof stress of direct aging material reached 1500MPa, and 107 cycle fatigue endurance limit topped 775MPa. Such improvement of mechanical properties was originated from the homogeneous dispersion of fine alpha phase.抄録全体を表示PDF形式でダウンロード (5829K) -
大竹 一友1992 年 63 巻 4 号 p. 303-309
発行日: 1992/10/15
公開日: 2009/05/25
ジャーナル フリーThe present situations of energy consumption over the world and in Japan are compared. It is described that the coal must become one of the most important energy sources among the fossil fuels if we would continue to produce energy by combustion. The present levels of energy conversion efficiency from thermal to mechanical energy are introduced to recognize how inefficient energy systems are being used and stressed how to improve the present energy systems. Cogeneration systems applied to the underground city (must be built or reconstructed) supported by an inland electric power station would be one of the best ideas to increase the total thermal efficiency. Big forest will cover this underground city to avoid the heat island effect produced by the present city system. In order to make the atmosphere clean in the under developing countries it is introduced that the capsuled ash-rejected-coal containing de-NOx and de-SOx agents is under developing in the author's laboratory. From the standpoint of view on plastic material recycling the capsule material would be of wasted plastics. To realize this system the chemical components in the plastics must be regulated to avoid the additional air pollution.抄録全体を表示PDF形式でダウンロード (415K) -
冨山 茂樹, 成田 正尚, 小須田 道彦1992 年 63 巻 4 号 p. 310-316
発行日: 1992/10/15
公開日: 2009/05/25
ジャーナル フリーThough analysers used in the production line of the steel making industry have high accuracy and are automated, sample preparation for these analysers is still mainly done manually, and many companies are investigating and adopting automatic sample preparation processes.
Especially the analysis in the production line of special steel industry must treat a great variety of steel material, and it is very difficult to get swarf samples for carbon and sulfur analysis from very hard material, and this makes it difficult to automate the sample preparation process.
This time, for carbon and sulfur analysis, the authors adopt a new procedure of “cut cample and get slice sample→soften slice sample by high frequency heating→punch small tablet sample out from slice sample” instead of the current procedure of getting a swarf sample. Using this procedure, the authors developed a new automatic sample preparation machine, which makes samples for X-ray fluorescence analysis, photoelectric emission spectroscopic analysis, as well as samples for carbon, sulfur and nitrogen analysis simultaneously within 90 seconds, and thereby succeeded in establishing a fully automatic sample preparation process.抄録全体を表示PDF形式でダウンロード (5891K) -
向井 碩哉, 中村 久三郎, 宮嶋 孝士1992 年 63 巻 4 号 p. 317-326
発行日: 1992/10/15
公開日: 2009/05/25
ジャーナル フリーThe Machinery Div. of Daido Steel Co., Ltd. has started to supply the large top charge type round aluminum melting furnaces in Japan, licenced by Gautschi Electro-Fours SA, Taegerwilen, Switzerland.
Special features of Gautschi standard design of the furnaces, that are proven in numerous installations throughout the world, are optimum efficiency, high and variable melting rate, ease of operation, low maintenance, high operation rate, and minimum melt loss. This Europe originated furnace design concept has interesting points which are differed from that of the US one.
The important points of the melting process is getting the highest heat transfer ratio from the burner flame jet to the piled up melting material with minimum metal oxidation. Some of the main function of the furnaces are the sophisticated combustion control and the furnace pressure control for keeping the lowest residual oxygen with high combustion efficiency.
The main specifications for typical capacity furnaces are shown in the list.抄録全体を表示PDF形式でダウンロード (3435K) -
市岡 雄二1992 年 63 巻 4 号 p. 327-333
発行日: 1992/10/15
公開日: 2009/05/25
ジャーナル フリーRecently customers have required round steel bars assured of the surface integrity. In order to fulfil such requirement, a new quality assurance system has been developed and already installed in the shop. It consists of a computerized flaw detector through fluorescent magnetic particles and a fully automatic grinding machine.
At first the particle distribution is taken by CCD cameras. This image is processed and diagnosed by computers and then the surface defects are mapped out into the memory.
Later they are removed from the surface through a grinding machine controlled by the computer.
Employing the new system, round steel bars are guaranteed from the surface defects 0.1mm or more deep.抄録全体を表示PDF形式でダウンロード (4798K)
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