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後続誌
63 巻, 4 号
選択された号の論文の8件中1～8を表示しています
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研究論文
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笹栗 信也, 松原 安宏, 大城 桂作1991 年 63 巻 4 号 p. 329-334
発行日: 1991/04/25
公開日: 2011/07/08
ジャーナル フリーHigh chromium cast iron containing 26 % Cr and mild steel were bonded by means of brazing with pure copper filler, and relationships between bonded microstructures and bonding conditions were clarified.
When the assembly of cast iron plate, 50 μm thick copper filler and steel plate was held at 1353 K to 1453 K for 0.6 ks to 2.4 ks in a vacuum of 1.33 × 10-2 Pa, both high chromium cast iron and steel dissolved into molten copper. Then Fe-rich crystals appeared from the cast iron side and they developed in a rod-like shape towards steel, while the dissolution of mild steel continued.
Alloy concentrations of the crystals were found to be 85 % Fe, 4 to 8 % Cr, 6 to 10 % Cu and 0.5 % C by EPMA and EDS analyses. The length of rod-like crystals (LA) and the width of bonding zone (WB) increased with an increase in both the bonding temperature and the holding time. Particularly, LA and WB became larger in proportion to the square root of the holding time, which indicates that the growth of Fe-rich crystals is closely related to the dissolution rate of steel. Microhardness of the crystals ranged from 143 Hv to 325 Hv, and it was higher than that of the mild steel. It could be consequently expected that the formation of such Fe-rich crystals in the copper filler has an effect to strengthen the joints.抄録全体を表示PDF形式でダウンロード (606K) -
鄭 寅謨, 池永 明, 川本 信1991 年 63 巻 4 号 p. 335-339
発行日: 1991/04/25
公開日: 2011/07/08
ジャーナル フリーIn order to modify the surface of cast iron, the study was carried out concerning the influence of vibration on the infiltration of melt into the surface alloying layer made with metal particles. The ferrochrome particles, mixed with a binder and applied to four holes in the bottom of mold, were used as surface aloying particles. The vibrations with maximum acceleration value in a range of 1 G to 3 G are controlled by a frequency and introduced into the mold, and the melt was finally poured into the vibrating mold. In this paper, results showed that the infiltration capacity of the melt relative to the surface alloying layer was remarkably improved by the application of vibration, and showed the influence of ferrochrome particle diameter and pouring temperature on the infiltration capacity of melt.抄録全体を表示PDF形式でダウンロード (568K) -
小野 幸徳, 清水 亮, 村井 典子, 大城 桂作1991 年 63 巻 4 号 p. 340-346
発行日: 1991/04/25
公開日: 2011/07/08
ジャーナル フリーHigh chromium cast iron products are replacing low chromium irons because of their superior strength, toughness and wear resistance, and ASTM 1-D type high chromium iron containing graphite was also developed for a hot steel strip mill. To obtain a proper distribution of graphite consistently, eutectic irons with 7.5 to 9.5 % Cr, 0 or 5 % Ni and 2 to 2.6 % Si were quenched by water jet spray while freezing unidirectionally, and the solidification processes of the irons were studied. (Cr, Fe)7C3+γ eutectic solidified in corn-like cells first, and (Fe, Cr)3C+γ eutectic and then graphite +γ eutectic followed in Fe-7.5 % Cr-2.6 % Si-3.78 % C alloy. EPMA analysis of alloy compositions in the melt around eutectic cells revealed that the chromium content decreased from 7.5 % to about 4 % and silicon increased from 2.6 % to 4 % with the progress of solidification. These changes in alloy concentrations of the melt affected each eutectic temperature, and caused the above variation in eutectic reactions. In the alloys containing 7.5 % Cr, 5 % Ni and 2.6 % Si, (Cr, Fe) 3C+γ eutectic could not appear because nickel and silicon lowered the (Fe, Cr)3C+γ eutctic temperature and raised the graphite+γ eutectic temperature. Inoculation with ferrosilicon is very effective for distributing fine graphite flakes around (Cr, Fe)7C3+γ eutectic cells.抄録全体を表示PDF形式でダウンロード (666K) -
西 直美, 駒崎 徹, 高橋 庸輔1991 年 63 巻 4 号 p. 347-352
発行日: 1991/04/25
公開日: 2011/07/08
ジャーナル フリーThe solidification phenomena within a shot sleeve and formation mechanisms for microstructures of JIS-ADC10 alloy die castings were investigated in samples prepared an using 90 metric tonne locking force cold chamber die casting machine. The solidified structure of the as cast materials were examined by optical microscopy. Quantitative analysis of microstructure was done with color image analyzer. The microstructures of JIS-ADC10 alloy after die casting consisted of coarse α phase with dendrite arm spacing (DAS) above 10 μm, fine α phase with DAS 5 to 10 μm and fine eutectic structures. The amount of coarse α phase increased with time from pouring molten metal into the shot sleeve to injection initiation. The amount of coarse α phase increased with decreasing pouring temperature. The coarse α phase was formed in the shot sleeve and injected scatteringly into die cavity. Two other types of abnormal structures which solidified in the shot sleeve existed in the die castings microstructure in addition to the coarse α phase. The fast was a scattered structure which exhibited a planar interface with the matrix. The second was a massive structure which agglomerated coarse α phase and coarse eutectic silicon.抄録全体を表示PDF形式でダウンロード (703K) -
水野 慎也, 日比野 義博, 関口 勉, 石川 秀雄1991 年 63 巻 4 号 p. 353-357
発行日: 1991/04/25
公開日: 2011/07/08
ジャーナル フリーInfluence of notch on the fatigue limit of austempered spheroidal graphite cast iron (ADI) was examined by Ono-type fatigue testing machine, and structure vs notch sensitivity was cosidered. 1) The notch sensitivity of ADI on the fatigue limit is insensitive as compared with FCD700 and S50C. 2) The η of ADI is affected by hardness, retained austenite and martensite. The η increases as hardness is raised, especially the η increases abruptly at about HV 350. The η decreases as retained austenite is increase by stress relaxation of retained austenite. The η increase as martensite is increases by stress concentration and lowering of plastic deformation ability.抄録全体を表示PDF形式でダウンロード (550K) -
佐藤 敬, 松本 昇, 米田 保夫1991 年 63 巻 4 号 p. 358-363
発行日: 1991/04/25
公開日: 2011/07/08
ジャーナル フリーCrucible and mold materials for producing chromium castings were investigated. Electrolytic chromium was induction-melted in alumina, magnesia, and lime crucibles under an argon atmosphere of 50 kPa. The tests revealed that the lime crucihle made by hand tamping calcined calcium oxide powder was superior in resistance to cracking and melt intrusion. Alumina crucible was attacked by the melt more and magnesia crucible was subjected to thermal shock more than the other ones. Deoxidation and desulfurization down to 40 ppm O and 10 ppm S were achieved by the addition of about one mass percent of aluminium to the melt in the lime crucible. Nitrogen contents of chromium after melting were the same as those of the chromium charged. Ceramic shell molds made of a slurry of zircon sand and ethyl-silicate reacted vigorously with chromium melt. Good results were obtained by using solid investment molds made of fused lime powder mixed with calcium chloride-ethanol solution. Of the oxides studied, only lime showed promise of success as a crucible and mold material for making chromium castings.抄録全体を表示PDF形式でダウンロード (878K)
技術報告
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土田 正信1991 年 63 巻 4 号 p. 364-369
発行日: 1991/04/25
公開日: 2015/01/22
ジャーナル フリーPDF形式でダウンロード (2780K)
解説
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塩田 重雄1991 年 63 巻 4 号 p. 370-378
発行日: 1991/04/25
公開日: 2015/01/22
ジャーナル フリーPDF形式でダウンロード (3881K)
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