巻号一覧
51 巻, 4 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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山口 国男, 杉浦 三朗, 出向井 登1980 年 51 巻 4 号 p. 237-241
発行日: 1980/11/15
公開日: 2009/05/25
ジャーナル フリーSome basic problems on water atomization of liquid metals were investgated.
The results were as follows:
(1) The slit of the water nozzle was expanded by hydrostatic pressure, and the velocity of the water was proportional to the root of the pressure.
(2) Splashing up of the liquid metal could be suppressed as the vertical angle of the conical water spray was reduced below 45°.
(3) It was more advantageous for getting good yield to raise the water pressure than to increase the water flow rate.抄録全体を表示PDF形式でダウンロード (242K) -
杉浦 三朗, 草加 勝司, 出向井 登, 能藤 彰1980 年 51 巻 4 号 p. 242-251
発行日: 1980/11/15
公開日: 2009/05/25
ジャーナル フリーThe recent powder metallurgy has a strong demand for spherical less-oxidized alloy powders in the market of sintered filters, electromagnetic clutch, plasma spray etc.
Accordingly, some technologies to produce the said alloy powders in the use of the water-atomization equipment have been developed.
First, there was made spherodization of the particle shape of stainless steel powders by controlling Si and B content, superheart temperature of melt and jetting pressure for water-atomization to some extent.
Secondly, further spherodization of particle shape of powders could successfully be obtained by special physical treatment after atomization, with lowering the oxygen amount of powders. As the result, the sintering-rate of powder was appreciably promoted under the probable influence of induced strain on the surface of particle.
There was finally established the industrial technique for providing the spherical alloy powders by means of gas-atomization with rapid quench in water, allowing the coverage of more powder applications.抄録全体を表示PDF形式でダウンロード (11655K) -
加藤 哲男, 草加 勝司, 久田 建男1980 年 51 巻 4 号 p. 252-263
発行日: 1980/11/15
公開日: 2009/05/25
ジャーナル フリーAn investigation was made of influence of Cu addition up to 6% on some properties of SUS304L type stainless steel powders manufactured by the water-atomization. The results were as follows:
(1) Cu addition decreased ferrite content of atomized powders, lowering particle hardness and also decreased particle hardness and also decreased martensite content induced by compacting. As the result Cu addition improved compressibility and compactibility of powders. 1% Cu addition was equivalent to 0.37% Ni addition for compressibility of powders.
(2) Cu addition improved tensile strength and impact value of sintered compacts, when Ni content was 10.5%.
The tensile strength of lower Ni equivalent sintered compacts became higher in proportion to the amount of α-phase.
(3) Cu addition improved cold formability of sintered compacts. 1% Cu addition was equivalent to 0.35% Ni addition for cold formability. The effect of Cu addition on cold formability was almost equal to that on compressibility of powders under the same influence of plastic deformation.
(4) Cu addition improved the corrosion resistance of sintered compacts in boiling 5% H2SO4 solution.抄録全体を表示PDF形式でダウンロード (4644K) -
草加 勝司, 久田 建男, 中村 貞行1980 年 51 巻 4 号 p. 264-271
発行日: 1980/11/15
公開日: 2009/05/25
ジャーナル フリーAn investigation was made of the influence of pressing and sintering conditions, and S addition up to 0.4% on the machinability of SUS304L and other sintered alloy steels manufactured by the water atomization.
The results were as follows:
(1) The sintered density gave remarkable influence on cutting resistance. The resistance got smaller first, and then larger with increasing density having the minimum value around 7g/cm3 of density.
(2) The surface roughness of SUS304L sintered steel was improved with smaller feed rate and higher cutting speed in turning.
(3) The cutting resistance of SUS304L and 316L sintered steels got smaller with increasing S-content in powders. As the result of it, the tool life was remarkably improved for SUS304L sintered steel bearing 0.2% S.抄録全体を表示PDF形式でダウンロード (6314K) -
大澤 秀雄, 山田 誠吉1980 年 51 巻 4 号 p. 272-278
発行日: 1980/11/15
公開日: 2009/05/25
ジャーナル フリーLow carbon (C about 0.1%)-12%Cr heat resisting steel is a martensitic stainless steel with both high strength and ductility given by hardening and tempering and is widely being employed as steam turbine blade steel.
This steel, however, has what is called “impact transition temperature”, that is to say, impact energy rapidly decreases near room temperature and embrittles. And this is one of the demerits of this steel.
After investigation of various properties of steel into which Nb is being individually and slightly added (less than 0.15%) to stabililize and refine N in the steel for the main purpose of improvement of this demerit it was recognized that the addition of about 0.02∼0.05% makes the impact transition temperature lowered as much as about 40°C and improves the ductility remarkably and at the same time the addition raises strength and creep rupture properties can be improved.
Based on this investigation it was able to obtain stabilized quality in manufacturing 0.1%C-12%Cr steel.抄録全体を表示PDF形式でダウンロード (334K) -
大宝 雄蔵, 木村 泰廣1980 年 51 巻 4 号 p. 279-286
発行日: 1980/11/15
公開日: 2009/05/25
ジャーナル フリーRecently a new type of gas turbine-generator has been developed to utilize directly the expansion pressure of evaporating LNG. The material for the turbine blades should satisfy the below requirements.
Tensile strength at R.T.>60kgf/mm2 FATT<-75°C
Authors tried to optimize Ni content in a candidate material, 0.1%C-12%Cr-1%Mo steel containing up to 5%Ni.
Austenitizing temperatures were fixed at 1000°C for 0 to 2%Ni steels and at 950°C for 3 to 5%Ni steels respectively, which are 100 to 150°C higher than Ac3 for each. Tempering was carried out at 550 to 850°C.
The results are as follows.
(1) Tensile strength at R.T. is always more than 60kgf/mm2 for all steels with and without Ni.
(2) Charpy V-notch impact values at R.T. show maxima when steels are tempered at temperatures 30°C higher than Ac1, which is lowered by Ni addition.
(3) Ni lowers FATT significantly and steels containing 3% or more Ni possess FATT below-75°C.
(4) The above effect of Ni is to be attributed to the microstructural change of steels with Ni contents. Firstly higher Ni steels show finer structures, which are segmented by reverse transformed austenite along inherent martensite lath boundaries during tempering at temperatures mentioned in(2). Secondly steels containing 4% or more Ni contain much amount of retained austenite, which retards the propagation of crack.抄録全体を表示PDF形式でダウンロード (7414K) -
加藤 哲男, 藤倉 正国, 竹内 宥公, 川崎 成人1980 年 51 巻 4 号 p. 287-295
発行日: 1980/11/15
公開日: 2009/05/25
ジャーナル フリーHigh manganese austenitic steel has recently been applied as non-magnetic structural material. An investigation was made about the influence of P as impurity, S for improving machinability and also V for increasing proof strength upon weld crack sensitivity of high manganese steel. As the results it was found that addition of 0.06% S and 0.6% V is not harmful to weld crack sensitivity and welding crack can be prevented by making P content less than 0.025%. Furthermore, obtained weld joints were confirmed to have favorable mechanical and magnetic properties.抄録全体を表示PDF形式でダウンロード (10160K) -
服部 清治1980 年 51 巻 4 号 p. 296-310
発行日: 1980/11/15
公開日: 2009/05/25
ジャーナル フリーRecently, in the building business circle, with the progress of reinforced structure of getting bigger and higher the strength and diameter are changing and furthermore, the prefabricating method is being adopted for energy saving of reinforced work.
Accordingly, mechanical joints of high reliability are required.
The writer et al developed squeeze joint method which is a mechanical jointing method of deformed bars.
The squeeze joint is carried out with a thickwalled steel tube sleeve which is squeezed onto the deformed bar by a die.
In this paper, it has been clarified that optimum vaiues of 3 elements (reduction ratio, section ratio and sleeve length) in SJ function are 0.85, 1.25 and 5 knots of deformed bar respectively.
From results written here under it was confirmed that this SJ joint fully satisfied joint judgement standard “A” by RPCJ committee.
The test results of squeeze joint performance are as follows:
1) Tensile strength is higher than JIS standard strength of reinforced deformed bar
2) At 0.95σyB: Joint E'>0.7E
3) At 0.70σyB: Joint E'>E
4) Residial elongation at (0.95σyB→“0”): <0.3mm
5) At max. load: Elongation>3%
6) After 20 times load reversals of 95%σyB tesion and 0.5σyB compression: Joint E'>0.5E抄録全体を表示PDF形式でダウンロード (2347K) -
山崎 道夫, 原田 広史1980 年 51 巻 4 号 p. 311-317
発行日: 1980/11/15
公開日: 2009/05/25
ジャーナル フリーPHACOMP enabled the prediction of the formation of harmful TCP-phases in superalloys. First practical use of PHACOMP was for the limitation of composition ranges of commercial alloys. Then PHACOMP was applied for the development of new alloys. An example of computer-aided alloy design for nickel-base superalloys by the authors is described.
In future, alloy design will be made more widely by the aid of computerized system of data base.抄録全体を表示PDF形式でダウンロード (1929K)
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