Tetsu-to-Hagane

Making of Self-Fluxing Sinter and the Blast Furnace Practice with Its 100% Sinter Burden

Kenichi Kasai, Takeje Sanematsu

1959 Volume 45 Issue 5 Pages 491-499
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_491

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In the sinter which is self-fluxed by adding the finely ground limestone, the formation of unreducible fayalite is obstructed or the fayalite disappears. Moreover, the glassy silicate matrix which prevents a gas reduction by surrounding iron oxide will disappear.
For making self-fluxing sinter, the exact control of blending and weighing, especially the correct addition of return fines, coke breeze and limestone is the most important. The suitable size of coke breeze as sinter fuel is under 5mm and one of limestone is under 3mm.
As a blast furnace burden, the self-fluxing sinter proves most effective when a furnace is operated with its 100% sinter burden. It seems possible to assume that by this 100% self-fluxing sinter burden practice, the coke rate can be reduced to below 550kg per metric ton of pig iron and the productivity of a furnace can be increased to above 1.3 metric tons per day per cubic meter of inner volume.
The results obtained by this practice at Kokura Steel Works, Sumitomo Metal Industries Ltd. were satisfactory and proved the above mentioned improvements in its operating data.
We think, this practice, using a fully self-fluxed sinter burden, is the last step in the series of ore beneficiation process that are found to be advantageous by roasting ores before charging.

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Influence of Various Elements on the Graphitization of High Carbon Steel (Part 2)

Study on the graphitization of high carbon steel-II

Naomichi Yamanaka, Kunio Kusaka

1959 Volume 45 Issue 5 Pages 499-506
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_499

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The authors studied upon the influence of various elements on the graphitization of highcarbon steel made from electrolytic iron or sand iron with 0.01% or 0.05% aluminum addition. Samples were water-quenched from 870°C or cold drawn from 10φ to 8φ, and then heated for 24, 48, 72, 100 and 150 hours at 650°C. Results obtained were as follows:
(1) Silicon promoted the graphitization of the high carbon steel after water-quenching and cold drawing, and manganese inhibited the graphitization.
(2) The carbide forming elements such as chromium, molybdenum and tungsten inhibited graphitization and chromium was most effective.
(3) Titanium, zirconium and boron promoted the graphitization very markedly after water-quenching and accelerated the graphitization after cold drawing. Vanadium restrained the graphitization after cold drawing, but accelerated graphitization after water-quenching as the vanadium increasedt to over 0.1%.
(4) Nickel promoted the graphitization after cold drawing and copper had littel effect on the graphitization. Columbium inhibited the graphitization after cold drawing, but accelerated the graphitization after water-quenching.
(5) Tin inhibited the graphitization very markedly after water-quenching and cold drawing. Phosphorus, tellurium, antimony and arsenic restrained the graphitization. High carbon steel made from ordinary scrap was highly resistant to graphitization in the presence of small amounts of tin.

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Ball-Bearing Steel Made with a Vacuum Induction-Furnace

Manabu Ueno, Hirooki Nakazima

1959 Volume 45 Issue 5 Pages 506-511
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_506

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In this report, the austenitizing behaviour and durability of the ball-bearing steel, made with a vacuum induction-furnace, were researched by means of the Rockwell hardness tester, lineal analysis, X-ray integrated intensity method, electrolytic isolation method and rapid life-testing machine.
The results obtained were as follows:
(1) In the ball-bearing steel made with a vacuum induction-furnace, the gas contents and non-metallic inclusion were very little in comparison with the air-melted steel.
(2) The austenitizing behaviour of the vacuum-melted steel was not different to one of the air-melted steel.
(3) The mean cycle to flaking of the vacuum-melted steel was superior to one of SKF ball-bearing steel in the results of the rapid life-testing machine, but its difference had no reliability at 95 per cent confidence coefficient.
The standard deviation of the vacuum-melted steel was inferior to one of SKF ball-bearing steel. It is deduced from this fact that the content of non-metallic inclusions, which is considered as a main unfavorable factor of the durability of ball-bearing steel up to this time, may not be a main factor to fatigue.

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On Carbides in High-C High-V High Speed Steels

Study on carbides in commercial special steels by electrolytic isolation-VIII

Tomo-o Sato, Taiji Nishizawa, Kousuke Murai

1959 Volume 45 Issue 5 Pages 511-516
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_511

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In the present study, X-ray and chemical analyses were carried out on carbides isolated electrolytically from several high-V high speed steels, and the effect of carbon, tungsten and vanadium contents on the constitution of carbides in these steels were discussed. Carbides in high-V high speed steel are MC, M₆C and M₂₃C₆, and the amount of these individual carbides varies depending on the steel composition.
The carbon-vanadium ratio is the most considerable factor. If this ratio is too low, the steel contains no M₂₃C₆, and is therefore incapable of being supplied with sufficient carbon into austenite for the formation of high hardness martensite on quenching. On the contrary, if this ratio is too high, the steel contains excessive amounts of M₂₃C₆, and the large amounts of austenite will be retained by quenching from the usual hardening temperature.
The desirable relation between carbon, tungsten and vanadium contents in high-V high speed steel was deduced approximately as follows

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Hot-Cold Work and Bending Creep Property of 16-15-6 Type Alloys

On the function of nitrogen as an alloying element in heat-resisting materials-III

Masazo Okamoto, Ryohei Tanaka, Akira Sato, Takeo Ishizuka

1959 Volume 45 Issue 5 Pages 517-522
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_517

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This study covers the hardening accompanied by hot-cold working and bending creep property of low Ni Timken 16Cr-15Ni-6Mo(-7.5Mn) type alloys. Main results obtained were as follows:
(1) For this type alloys, in general, the hardness became considerably higher by hot-cold working than by cold working, and the trend became significant with increasing content of N and C. From the above results, it was concluded that the precipitation of nitrides or carbides probably occurred duringthe hot-cold working of the alloys and the hardening accompanied by the precipitation superimposed on the work hardening.
(2) The hot-cold worked specimens maintained the higher hardness than the solution treated one even after the aging at 700°C for 500h. The working, however, seemed to be effective only when the alloys were used at temperatures below 700°C, since it accelerated the aging and resulted in rapid softening at 700°C.
(3) In the hot-cold rolled state, the hardness distribution of the specimens became heterogeneous and the hardness in the outer layer was considerably higher than that in inner one, and this trends maintained still after aging at 700°C for 500h.
(4) Bending creep property at 700°C of the alloys subjected to 20% hot-cold working by rolling was improved remarkably with the content of N added. In the range of Ni content from 13 to 17%, the alloy containing 15% Ni was superior in the property, though the effect of Ni content was not remarkably, while addition of carbon reduced the toughness of the alloys rupturing in comparatively short testing time. In the range of the present experiment, the 16-15-6 type alloy was considerably superior to the standard Timken 16-25-6 alloy, and the hot-cold working of each alloy improved the bending creep property significantly.

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Effect of Heat Treatment on Mechanical Properties of M252

Studies on nickel-base heat-resisting alloys-III

Taro Hasegawa

1959 Volume 45 Issue 5 Pages 522-527
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_522

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The optimum temperature of solution-treatment to get high stress-rupture life is 1065°C. Solution-treatment at temperature higher than 1065°C causes grain coarsening and overaging during long-time tegting, and decreases the resistance of creep rupture.
Specimens solution-treated at 1065°C have superior creep rupture life to the specimens solution-treated and aged at 750°C. Bat the life of stress-rupture testing of the formet becomes inferior to the latter in longer testing time.
The stress-rupture strength at 750°C of specimens heat-treated by H, which contains aging of 24 hours at 840°C, 16 hours at 760°C and 16 hours at 816°C is superior to other heat treatment. But at 816°C stress-ruptnre strength of specimens heat-treated by H is inferior to other heat treatment, because at higher testing temperature, heat treatment H causes overaging during stress-rupture testing.
The heat treatment B which contains water cooling after solution-treatment gives higher short-time tensile strength and stress-rupture strength than other heat treatment. This forms a contrast to Nimonic 80A on the effect of heat treatment.

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On the Recent High-Tensile Steels (II)

Masayoshi Yamaki

1959 Volume 45 Issue 5 Pages 528-542
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_528

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Heating Operation of Coke Ovens

Atsushi Nishio

1959 Volume 45 Issue 5 Pages 542-556
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_542

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Cold Working (II)

Bending

Yasuo Kasuga

1959 Volume 45 Issue 5 Pages 557-566
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_557

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[title in Japanese]

1959 Volume 45 Issue 5 Pages 567-570
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_567

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[title in Japanese]

1959 Volume 45 Issue 5 Pages 571
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_571

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[title in Japanese]

1959 Volume 45 Issue 5 Pages 572-575
Published: May 01, 1959
Released on J-STAGE: May 26, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.45.5_572

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