巻号一覧
42 巻, 2 号
選択された号の論文の9件中1～9を表示しています
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藤田 護1971 年 42 巻 2 号 p. 106-112
発行日: 1971/04/15
公開日: 2009/05/25
ジャーナル フリーConcerning manufacturing of exhaust valve for automobile by hot extrude forging method using hot rolled bar of 21-4N steel, the influence of the inclusions on the forgeability have been studied in this report.
The results are as follows:
1. Whether the forgeability is good or bad can be evaluated enough by forging quality rating (F.Q.R.) obtained by an hot upsetting test which has pretty good correlation with the defect rate so the defect rate of actually forged valves is unnecessary to be investigated.
2. After checking the relationship between the F.Q.R. used for evaluation of forgeability and non-metalic inclusions, it was recognized that there were no individual correlation among sulphide and oxides (alumina, silicate etc.), but there was pretty good correlation between the said F.Q.R. and multiple large and longer inclusions (stringer type inclusion or elongated clusters of inclusion) combined with these inclusions. If these should be existed just under sub surface in stringer state, the forgeability will extremely become worse.
3. Through analyzing the structure of multiple large and longer inclusions by E.P.M.A., it were confirmed that the main components were oxides of Mn, Al and Si and the existence of Cr oxides and the distribution S and Ti were also found.
4. In order to grasp the quality of non-metallc inclusions the combination of the measurement of clearness by ASTM-A method and machined hairline test are recommendable.抄録全体を表示PDF形式でダウンロード (8826K) -
森 成敏, 広瀬 輝夫1971 年 42 巻 2 号 p. 113-118
発行日: 1971/04/15
公開日: 2009/05/25
ジャーナル フリーIt has been known that producing good quality hot strips with ductile micro structure of high grade high alloy steels having big single weight by hot rolling is very difficult.
However on the base of the results obtained after a long years' study of hot rolling of high grade high alloy steels by single planetary mill, quite a few merits of the said mill can be effectively available in case of rolling various high alloy steels and also they, comparatively, can be rolled with ease.
Even a high speed steel that can hardly be processed could also be hot rolled into an ductile hot strip by 400φ single planetary mill.
In this case, the underwritten conditions are necessary:
1. The workrolls are to be thick.
2. To use an assembly of 8 piece planetary workroll.
3. To hot roll a slab as thin as approx 70% of high carbon steel raw material into a strip.
4. The ratio between “t” of plate thickness and “l'” of length of touching arc is to be more than 0.60
Also a correct calculation method of “l'” is being introduced.抄録全体を表示PDF形式でダウンロード (405K) -
渡辺 輝夫, 稲生 博, 森 昌平, 石田 二郎, 伊藤 哲朗1971 年 42 巻 2 号 p. 119-129
発行日: 1971/04/15
公開日: 2009/05/25
ジャーナル フリーHaving analyzed the influences of drawing apparatus, method and properties of materials, for improving those of the roller dies drawing, there envisioned a possible drawing of plus and minus 0.05mm tolerance through adequate countermeasurement exerted upon dimensional accuracy.抄録全体を表示PDF形式でダウンロード (2516K) -
福井 彰一, 上原 紀興1971 年 42 巻 2 号 p. 130-135
発行日: 1971/04/15
公開日: 2009/05/25
ジャーナル フリーSo far, it has been said that the ductility of metal containing hard particles depends only on the volume fraction of particles, f, and the ductility decreases with the increase of f. On the other hand, according to engineering experiences, it is well known about, at least, spheroidal carbon steels, that the larger cementite size, the better cold formability of it. Therefore, the purpose of this work is to investigate the influence of not only the amount of spheroidal cementite particles, but also, especially, the cementite particle size on the strength and ductility of spheroidized carbon steels. And the relationships between structural factors and work hardening charcteristics, rupture strength, rupture surface appearances and so on were studied, and the following results were obtained;
(1) Work hardening characteristics coincides, on the whole, with the theory presented already, but power number of f/(1-f)d is about 0.20.
(2) The amounts of strain before rupture, including almost from 10% of rupture strain corresponding to strain at the onset of local necking to 80% of rupture strain, have relation to work hardening rate, that is, the more work hardening rate, the less strain before rupture.
(3) The contribution of spheroidal carbide size to rupture ductility is found to be little but distinct, and the bigger carbide size, the more rupture ductility.
(4) Mean diameter of dimples of ruptured surface is about 1.5 or 2 times ‘true’ mean free ferrite path in the range of experiment.
(5) The tensile fracture stress at the longitudinal axis of specimen increase with the decrease of d and f. Furthermore, the results (1), (3), (5), mentioned above, were expressed as experimental equations.抄録全体を表示PDF形式でダウンロード (314K) -
加藤 哲男, 草加 勝司1971 年 42 巻 2 号 p. 136-145
発行日: 1971/04/15
公開日: 2009/05/25
ジャーナル フリーFollowing a study of free-machining magnetic soft iron and magnetic stainless steel, a further study of machinability of practical magnetic silicon steel containing up to about 4% was made by adding Pb, and the underwritten results were confirmed.
1. Extension of a tool life, without damaging its original magnetic properties, was possible and high machinability was provided by Pb addition.
2. Both the extension result and cracking of chips get somewhat decreased if Si-contents increases.
3. Regardless of Pb addition, it was confirmed that the more Si-contents the better magnetic properties, the higher electric resistance and mechanical properties. Soft iron and 1% silicon steel once reach the magnetical optimum value, under around 850°C annealing temperature, but in the high silicon steel with transformation, the higher annealing temperature the better magnetic properties.
4. Some mechanical properties, such as wear resistance, was also improved by Pb addition.抄録全体を表示PDF形式でダウンロード (4707K) -
大西 正義, 山野 清市, 西尾 内匠, 嵯峨 仙三, 寺島 敏男1971 年 42 巻 2 号 p. 146-153
発行日: 1971/04/15
公開日: 2009/05/25
ジャーナル フリーThe sliding nozzle being used currently is consisted of refractory plates and a nozzle bore for controling steel teeming process here in Japan and the said nozzle is being used all over the world with faster tempo.
The refactory parts are required to have, in their degree. more precise dimensions than those of conventional ones.
Particularly, each sliding glassy surface of the slide plates needs to be polished.
This sliding nozzle has been applied in degassing process, vacuum casting, continuous casting etc. and its excellency is duly confirmed under each operation.
Generally, in ingot teeming, 2 or 3 heats have been made without changing refractory parts.
After the experiment using 2 ton ladles we obtained the result of continuous usage of 14 charges as the maximum.
Application of this sliding nozzle is supposed to be important in future for improving automation of steel making process.抄録全体を表示PDF形式でダウンロード (6812K) -
須藤 一1971 年 42 巻 2 号 p. 154-161
発行日: 1971/04/15
公開日: 2009/05/25
ジャーナル フリーPDF形式でダウンロード (440K) -
1971 年 42 巻 2 号 p. e1a
発行日: 1971年
公開日: 2009/05/25
ジャーナル フリーPDF形式でダウンロード (9K) -
1971 年 42 巻 2 号 p. e1b
発行日: 1971年
公開日: 2009/05/25
ジャーナル フリーPDF形式でダウンロード (9K)
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