巻号一覧
後続誌
62 巻, 1 号
選択された号の論文の6件中1～6を表示しています
- |<
- <
- 1
- >
- >|
研究論文
-
田上 道弘, 宇佐美 正1990 年 62 巻 1 号 p. 19-24
発行日: 1990/01/25
公開日: 2011/07/27
ジャーナル フリーEffects of heat treatment and Cu, Al components, mass effect, mold type on the mechanical properties of Zn-Al foundry alloys were studied. Heat treatment at 360°C for 30 min, combined with an average transformation rate exceeding 370°C /min results in 20% improvement of tensile strength for as cast alloys. Tensile properties of alloys cast into graphite and metallic mold remain unchanged in as cast and heat treated alloys. Although decreasing Al content up to 8% results in 20∼30% lowering of tensile strength, increasing Al content up to 15% raises the tensile strength of heat treated alloys by 5∼10% . Cu addition of 3% cause an increase in tensile strength of alloys heat treated at 250∼300°C by 20∼35% . Cu content in 0.5∼3% do not change tensile strength for alloys heat treated at 360°C. With increasing sample weigth from 10g to 270g, tensile strength lowers 5∼20% and indicate mass effect in heat treatment.抄録全体を表示PDF形式でダウンロード (932K) -
藤田 武男, 大城 桂作, 福井 昻, 末永 允1990 年 62 巻 1 号 p. 25-30
発行日: 1990/01/25
公開日: 2011/07/27
ジャーナル フリーSpheroidal graphite cast iron containing 3.61%C, 2.21%Si, 0.4%Mn and 0.045%Mg were austempered at 375°C and 235°C for 2hr. The rolling contact fatigue strength of austempered cast iron was investigated by using a Nishihara-type rolling contact testing machine under a light oil lubricant, and the effects of bainite structures and relative sliding ratio on the rolling contact fatigue limit (F*) were studied. F* of lower bainitic spheroidal graphite cast iron was larger than that of upper bainitic iron, though the former worn and the surface rougher during rolling contact test. F* of the both lower and upper bainitic irons became smaller as the relative sliding ratio increased.抄録全体を表示PDF形式でダウンロード (757K) -
中江 秀雄, 影山 望, 鈴木 実1990 年 62 巻 1 号 p. 31-36
発行日: 1990/01/25
公開日: 2011/07/27
ジャーナル フリーGlass encapsulated method is a well known technique for getting large undercooling of bulky melt. Experiments were carried out to clarify nucleous agents for solidification of cast iron. Pure Fe-C and Fe-C-Si alloys were prepared from electric iron, electrode graphite (5N-purity) and 5N-silicon. Alkali-free glass and sodalime glass were used for encasing the melt. After the experiments, the crystallization of glass were inspected by micro X-ray diffraction.
The following results were obtained.
(1) Silicon in the alloys increases the undercooling of primary γ-phase. Especially, in case of alkali-free glass treatment for Fe-C melt, the undercooling is not recognized completely.
(2) The crystallization of glass is evidently recognized at the treatments in which the undercooling were small or could not found. Silicon in melt decreases the crystallization of the glass.
(3) Cristbalite crystallized in the glass acts as a heterogeneous nuclei for γ-iron.
(4) The melt encased by alkali-free glass, the undercooling of graphite eutectic temperature becomes larger than that of sodalime glass, and the eutectic solidification transits more easily from Fe-graphite system to Fe-Fe3C system.抄録全体を表示PDF形式でダウンロード (687K) -
松本 弘司, 岸武 勝彦, 入沢 毅, 恵良 秀則1990 年 62 巻 1 号 p. 37-42
発行日: 1990/01/25
公開日: 2011/07/27
ジャーナル フリーIron-carbon and Iron-carbon-silicon white cast iron rods were sprayed by use of a thermal spraying gun and the characteristics of the very rapidly solidified coatings were investigated by means of X-ray diffraction and micro-hardness test. Coatings about 0.1mm in thickness consisted of austenite and close-packed hexagonal ε-iron. The ε-iron phase decomposed to ε-carbide and martensite at temperatures lower than 200°C and the austenite phase broke up at temperatures lower than 400°C. X-ray diffraction profile of the coatings about 0.4mm thick revealed a very broad peak around (011) α through low temperature tempering during thermal spraying. The hardness of the coatings came to the maximum between 100°C and 400°C due to precipitation of fine ε-carbide or cementite and decreased gradually with an increase of tempering temperature over 400°C because of coarsening of carbide particles.抄録全体を表示PDF形式でダウンロード (852K) -
山口 薫, 松原 安宏1990 年 62 巻 1 号 p. 43-49
発行日: 1990/01/25
公開日: 2011/07/27
ジャーナル フリーEutectic high chromium cast irons containing 17%Cr and 26%Cr were produced for this research by making each of them solidify unidirectionally. Abrasion test with abrasive papers of SiC and Al2O3 ceramics was carried out using test pieces cut from the castings at several distances from the chill face. The wear resistance was evaluated in connection with parameters such as eutectic colony size (EW), fraction of boundary region of the colony where comparatively large massive chromium carbides are crystallized (SB) and the average diameter of chromium carbides in the boundary area (DC). Wear rate (RW) was influenced by sort and particle size of caramic. The Rw against SiC was larger than that against Al2O3 under the similar size of ceramic. In case of SiC, the RW increased with an increase in its particle size. The RW reduced as the EW increased, and the RW of 26%Cr iron was smaller than that of the 17%Cr iron even at the same values of EW. Both of the SB and the DC can be related to the RW without consideration of chromium contents of the specimens, that is, the RW decreased in proportion to the SB and the DC, respectively. The wear resistance of annealed specimens showed 1.3 to 1.6 times as small as that of the as-cast specimes. As for the relations between RW and macro-hardness of the specimens, the hardness resulting in the minimium wear rate was found to be near Hv 550.抄録全体を表示PDF形式でダウンロード (763K) -
高野 憲三, 名取 義勝, 菅沼 貞夫1990 年 62 巻 1 号 p. 50-55
発行日: 1990/01/25
公開日: 2011/07/27
ジャーナル フリーStrength properties of the CO2 silicate moulds hardened by vacuum gassing technique has been investigated, by using moulds stored in the normal foundry atomosphere and in the humidity-controlled chambers.
According to the results, mould strengths have been evident to be deteriorates on standing in the foundry atomosphere for long periods. This is due to the formation of carbonates by the absorption of CO2 from the atomosphere. Moulds which were stored in the closed chambers at specified humidity has shown appreciable increased in strength even after two months. And also the relations among the reaction ratio of Na-silicate and CO2, immediate (im.) strength and max. strength were defined.抄録全体を表示PDF形式でダウンロード (788K)
- |<
- <
- 1
- >
- >|