Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 45, Issue 10
Displaying 1-13 of 13 articles from this issue
  • Fundamental study on the removal of arsenic in limonite during ore-benefication process-II
    Susumu Sato
    1959 Volume 45 Issue 10 Pages 1131-1135
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
    Some consideration on the mechanism of removal of arsenic in limonite was made. Based on this mechanism some accelerating materials for arsenic removal were chosen and following results were obtained.
    (1) The mechanism of arsenic in limonite was as follows,
    This reaction was accelerated from right to left according to temperature rising. When CO existed in atmosphere, the reaction of arsenic removal was as follows,
    The reaction rate of equation (2) was faster than equation (1). From upper two equations, the hindering effect of O2 and CO2 on the arsenic removal reaction was understood.
    (2) The effect of accelerating materials for arsenic removal in limonite was tested in a laboratory.
    In this case, coke, coal, pyrite, FeCO3 and FeCl2 were chosen as accelerating material in consideration of arsenic-removal mechanism.
    The results were as follows.
    a) Coke and coal were effective for accelerating arsenic removal and coke was more effective than coal.
    b) Pyrite was also effective for accelerating arsenic-removal in some cases.
    c) FeCO3, MnCO3 and FeCl2 were not effective for arsenic removal.
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  • Kinetics of decarbonization in molten steel-II
    Takehiko Fujii
    1959 Volume 45 Issue 10 Pages 1135-1139
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
    The rate of decarbonization in a 100-t basic open hearth furnace was measured, and the relations between the rate of decarbonization and C, O contents in molten steel were examined. The following results were obtained.
    (1) The relation between the rate of decarbonization and C×ΔO was not obtained.
    (2) The relations between the rate of decarbonization and C were as follows.
    (a) C>0.30%: In one charge, there existed one or two large regions of carbon content by which the rate of decarbonization was not changed in molten steel. And this constant rate of decarbonization was changed by each region and each melt.
    (b) C<0.30%: The rate of decarbonization decreased in proportion to carbon contents in molten steel.
    (3) The relation between the rate of decarbonization and ΔO was not obtained. The reasons were as follows.
    (a) The value of oxygen content was obtained from samples which were taken from relatively bottom parts of molten steel.
    (b) C>0.30%: The oxygen content of molten steel was not changed so much. C<0.30%: Though O, O' equ., ΔO' and ΔO increased with carbon elimination, the rate of decarbonization decreased rapidly.
    (4) The rate of decarbonization in oxygen lance method was large compared with ore method.
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  • Studies on capped steel ingots-I
    Takeshi Kato, Junichi Imai, Yutaka Hirose, Hiroyuki Kajioka
    1959 Volume 45 Issue 10 Pages 1139-1144
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
    Using 2t, 4t and 8t bottle top molds, a number of test ingots of capped steel of C: 0.06-0.09% and Mn: 0.36-0.50% were made with varied teeming conditions, by application of widely different degrees of deoxidation.
    By the longitudinal section of these ingots, investigation about the rim zone and the distribution of blow hole was carried out and as the result the followings were clarified:
    1. The thickness of solid skin was controlled by addition of Al in the ladle and the pouring rate.
    2. The thickness of rim zone depended on the hitting time. The most important factor in determining the hitting time was the Al added in the ladle, when pouring height was constant.
    3. The less amount of Al added in the ladle and the better design of mold decreased ingot cracks.
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  • Comparison of vacuum-and air-cast steels-II
    Tonoya Suzuki, Toshihiko Asakuma
    1959 Volume 45 Issue 10 Pages 1145-1151
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
    The vacuum casting is no cure-all, but has a number of advantages. Following a through twenty months experience, the following benefits were recognized.
    (1) 60% of hydrogen in steel and 30% of oxygen were removed, but nitrogen content would not vary appreciably.
    (2) The vacuum pouring gave higher properties in directions transverse to the direction of work. It was noted that there was little or no change in tensile and yield strength, an improvement was indicated in elongation and reduction of area on the vacuum steel. Generally properties of the vacuum steel had less variances than those of air ingots.
    (3) Ultrasonic test had proved no internal defects.
    (4) Microscopic study and sand analysis indicated the reduction of non-metallic inclusions by 30%. But porous or spongy surface by the spraying resulted in increase of sand marks in gurface.
    (5) The segregation was not materially affected.
    The dendritic structure had less growth by the vacuum casting; and a ghost with microcracks was dissolved.
    (6) The vacuum pouring had resulted in elimination of the secondary cavity with a greater certainty.
    (7) The vacuum steel had indicated a freedom from flakes.
    (8) The heat treatment cycles would be reduced from a half to one third.
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  • Yosaku Koike, Yoiti Toda, Kunisuke Tihara, Tuneo Kuwahata
    1959 Volume 45 Issue 10 Pages 1152-1157
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
    This investigation was carried out to study the effect of the number of passes on the spread and elongation of bars. Tests were made by the two-high pinion-drive mill having plain rolls, with a 250mm diameter.
    The samples used in this test were square bars of low-carbon steel and the initial sections of them were respectively 25, 35 and 45mm squares. These bars were rolled at temperatures of 800°C and 1200°C down to total reduction of 40 per cent. in height.
    The reduction was achieved in one, two, three or four passes. In several passes the draught of each pass was equal. The results obtained were as follows.
    (1) As the number of passes increased, the total spread of the rolled bar decreased and the total elongation increased. This tendency was more severe at 800°C than at 1200°C.
    (2) In several passes, the spread of each pass was not equal.
    It increased with the number of pass.
    (3) The side-shapes of the bars after rolling became either concave or barrel shaped and the former shape was found on the bars of 35 and 45mm square, when rolled in three or four passes.
    The degree of barrelling increased as the bar size decreased.
    (4) The rolling load of each pass was measured by the load cells inserted between the mill screws and the roll chocks.
    The maximum load acted at the last pass when the reduction was achieved in several pass.
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  • Study on high strength structural steel-I
    Eiichiro Asano, Akizi Suseki
    1959 Volume 45 Issue 10 Pages 1158-1163
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
    Si-Mn high strength structural steel has been developed in Japan these few years, being supported by the recent tendency of lightening the weight of structure. In this report, the effect of addition of V and other elements such as Zr, Cr, Ti, Si, on Si-Mn structural steel were studied. In the case of laboratory test, there were 13 grades of samples. In the first group, containing 6 grades steel, the effect of V on Si-Mn structural steel were researched. In the second group, containing 4 samples, the effect of V and Zr or Cr or Ti were tested. In the third group, the effect of V addition on lower C-higher Si-Mn steel were studied. All samples were melted with a high frequency electric furnace and cast into 5kg ingots, then rolled to bars (9mmφ).
    Specimens were tested under three conditions such as rolled, heated and as air-cooled or furnace-cooled after heating and as-quenched and-tempered. Tensile strength, yield strength, elongation, and reduction of area were determined by tensile test. Hardness test, V-noched Charpy impact test, and microstructure test were also made. It was concluded as follows:
    (1) Tensile strength and yield strength rose, and elongation and impact value were decreased, with increasing V content. V also unified the microstructure and made ferrite grainsize refined. V behaved as anti-softening by tempering, which was seemed to depend on carbide formation.
    (2) Adding Cr or Ti in Si-Mn-V steel resulted in increasing tensile strength, but gave no effect on elongation and low-temperature impact value. Ti and Zr made ferrite grain-size refined, but Cr did not do so.
    (3) Even if C content was decreased from 0.2% to 0.1%C, the tensile strength was invariable when the Si was increased from 0.4% to 0.65%. The second, angle shape steel was made by Si-Mn-V steel, and special shape steel for the use of mine props was made by Si-Mn-Cr steel on production line. Si-Mn-V steel angle was determined by mechanical tensile test and by welding maximum hardness test. In the case of Si-Mn-Cr mine props steel, the effect of C content on heat-treated tensile properties were studied.
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  • Study on the chemical analysis of basic slag-III
    Shigeo Wakamatsu
    1959 Volume 45 Issue 10 Pages 1164-1168
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
    This investigation was undertaken to find rapid and accurate chemical methods for the analysis of basic slag. In the report (III), a simple combustion procedure and spectrophotometric methods were described for the determination of sulfur which are contained in basic slag. Combustion procedure: weigh a sample of 0.3-0.6 grams in to combustion boat. The boat is covered and preheated in the combustion tube for at least 2mn. The tube is stoppered and the flow of oxygen (800 to 1000ml. per 2mn.) started through the train. A temperatute of 1350 to 1400°C is maintained in the furnace.
    The combustion gases (SO2, SO3 etc.) are conducted into the absorbing solution. The absorbent consists of 50ml. of H2O2 (0.1%) and 10ml. of CuCl2 (0.009%). In the absence of F-, sulfur may be determined by titration with 0.01N NaOH. In the presence of F-, sulfurs is determined by titration with 0.04 BaCl2 using sodium rhodizonate as an indicator.
    Spectrophotometric method: 2 gram of sample mixed with 20 gram of Na2O2 is fused, the product is extracted with water. Make up to 100ml. with water. Pipet 20ml. of solution Add 30ml. of Fe3+-HClO4 solution. Measure the absorption at 380mμ in 1cm. cell against the blank.
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  • Yasuo Nosaka
    1959 Volume 45 Issue 10 Pages 1169-1180
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
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  • Other Squeezing Operations
    Yasuo Kasuga
    1959 Volume 45 Issue 10 Pages 1181-1186
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
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  • New Technique Development Division
    [in Japanese], [in Japanese], [in Japanese], [in Japanese]
    1959 Volume 45 Issue 10 Pages 1187-1210
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
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  • 1959 Volume 45 Issue 10 Pages 1200-1223
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
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  • 1959 Volume 45 Issue 10 Pages 1211-1217
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
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  • 1959 Volume 45 Issue 10 Pages 1218-1219
    Published: October 01, 1959
    Released on J-STAGE: May 26, 2009
    JOURNAL FREE ACCESS
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