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Volume 30, Issue 3
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Hideo Akasu1966 Volume 30 Issue 3 Pages 201-206
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTime-temperature-austenitization diagrams (T-T-A Diagrams) of variously preheat-treated 0.69 and 0.64% carbon steels were obtained to provide a guide for rapid heating and quenching operations. The experimental procedure was the same as in one of the previous reports.
The experimental results are as follows:
(1) Under different pre-heat-treatmentsw ith various lamellar structures, austenitization of normalized steel starts and finishes in the shortest time, followed by the as-rolled one, and the annealed one requires the longest time.
(2) Under different pre-heat-treatments of the as-quenched structure and various quench-tempered ones, austenitization of as-quenched steel starts and finishes in the shortest time, followed by the quenched and 150°C, 350°C and 500°C tempered ones, and the 500°C tempered one requires the longest time. However, austenitization of even the 500°C tempered steel takes a much shorter time than the normalized one.
(3) Steels involving segregated massive proeutectoid ferrite require a considerably long time for finishing of austenitization, so that they often suffer soft spots during rapid heating and quenching.View full abstractDownload PDF (2195K) -
Taichi Kamijo1966 Volume 30 Issue 3 Pages 207-212
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCubically aligned copper formed after 95 per cent rolling and annealing were cold rolled up to 96.7 per cent reduction in thickness. Slip rotations from (001)[100] to the stable end orientations occuring during rolling were investigated. The orientation spread around (001)[100] is little in case of low reduction. The rotation mainly about [100] axis parallel to the rolling direction, takes place during rolling up to 70 per cent, under the operations of a pair of the slip system in which the slip direction is nearly perpendicular to the transverse direction. It is found that the intensity maxima corresponding to the nearly (123)[\bar6\bar34] end orientation appear in the pole figure at the reduction more than 80 per cent. It seems that the initial displacements which lead to the end orientation must be due to the operation of the slip system which does not bear the highest resolved shear but accommodates a lateral spread.
With increasing rolling reduction, not only becomes the spread from (001)[100] about the rolling direction stronger, but also the intensity maxima corresponding to nearly (123)[\bar6\bar34] and the (110)[1\bar1\bar2] became higher at the same time. As a consequence of the process of developing the rolling texture, it is not probable that the grains having reached (110)[1\bar1\bar2] rotate towards the orientation near (123)[\bar6\bar34] by the extensive cross slip. But it can be considered that the grains on the way to the stable end orientation remain in the vicinity of (123) since the rolling plane normal cannot move in (110) owing to the contribution of cross slip, and accordingly the “pure metal” type texture will be developed.View full abstractDownload PDF (2254K) -
Toshio Doi, Humihiko Ishida, Tadashi Umezawa1966 Volume 30 Issue 3 Pages 213-219
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of cold working, final and intermediate heat treatments and amounts of cold working before and after intermediate heat treatment on the applied magnetic field vs. critical current density were examined on Nb-25 at%Zr and Nb-40 at%Zr-10 at%Ti alloys at the magnetic field transverse to the transport current at 4.2°K.
Although the critical current, density of Nb-25 at%Zr alloy was greatly increased by cold working, there was little effect due to heat treatment. Where as the critical current density of Nb-40 at%Zr-10 at%Ti alloy increased slightly by cold working, but there was an increase of about 102 A/cm2 in the order of magnitude by heat treatment.
The critical current density of Nb-25 at%Zr alloy was 3×104 A/cm2 at 60 KOe, while that of Nb-40 at%Zr-10 at%Ti alloy was 9×104, 6×104 and 6×103 A/cm2 at 60, 70 and 90 KOe, respectively. It was made clear that the latter had extremely superior properties.View full abstractDownload PDF (1399K) -
Toshio Doi, Humihiko Ishida, Tadashi Umezawa1966 Volume 30 Issue 3 Pages 220-225
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSStudy was made on Nb-25 at%Zr and Nb-40 at%Zr-10 at%Ti alloys with respect to the relationship between the internal structure and the critical current density, especially the effects of cold working and heat treatment on the critical current density when the transverse magnetic field was applied.
The principal cause assignable for the increase of critical current density of Nb-40 at%Zr-10 at%Ti alloy is to be sought in the increase of the localized internal stress due to precipitation.
It can be considered that the above-mentioned effect in Nb-25 at%Zr alloy is attributable to the increase of the localized internal stress due to the increase and rearrangement of dislocation textures.
Although the precipitation contributes considerably to an increase of critical current density at low fields, the dislocation has a favorable effect even at high fields.
It can be conceived that these effects are brought about since the flux density is high at a strong magnetic field and so the formation of flux bundles becomes easier. The flux bundle can only be trapped by tangled dislocations having a higher strain energy as the action of Lorentz Force on the flux bundles are large.View full abstractDownload PDF (2104K) -
Kunio Kusaka, Kazuo Ikushima1966 Volume 30 Issue 3 Pages 226-230
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPractically all sorts of gasoline for automobile engines contain tetraethyllead to improve their octane number or their resistance to knocking. Unfortunately the beneficial effects of tetraethyllead are accompanied by several disadvantages, due to the formation of inorganic deposits (mainly lead oxide) on the exhaust valves, including the fouling, corrosion and burning. The investigation has been made to determine the effect of alloying elements on lead oxide corrosion of 20Cr-11Ni type austenitic heat resisting steels. The test procedure is that lead oxide is heated to 915°C or 950°C in an alumina crucible and a preheated sample is exposured to molten lead oxide for 30 minutes. The weight loss of the specimen is then determined and this loss per unit surface area is used to evaluate the corrosion tendency of the steel. The results obtained are as follows. (1) The alloying elements which improve the corrosion resistance are Cr, Ni, Co and Mo. (2) The alloying elements which decrease the corrosion resistance are Si, W, Cu, P, As, Al, B, Zr, U and R. E.. (3) The alloying elements which have no effect on the corrosion resistance are Mn, C, N, Sn, Ti and V.View full abstractDownload PDF (1768K) -
Tadashi Hosoda, Toshio Matoba1966 Volume 30 Issue 3 Pages 231-237
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe deoxidation process of Mo during arc melting is studied using, C, TiH and B as deoxidizers. Especially the effect of B on the workability of Mo is investigated. The results are summerized as follows:
(1) The deoxidation reaction by C is proceeded, based on the reaction C+O=CO. The over-addition of C is not effectively used for deoxidation but causes the precipitation of intergranular carbides.
(2) TiH is effective as deoxidizer. The intergranular precipitates which are made by the addition of TiH are fine and dispersed. (TiH+C) is more effective as deoxidizer.
(3) B is useful as deoxidizer and also very effective in grain refinement.
(4) Mo containing B has two kinds of intergranular precipitates. The one is granule-like which is made by low B addition, the other is stripe-like by high B addition. Both precipitates seem to dissolve Mo oxide precipitates and to contribute to strengthen grain boundaries.
(5) Mo containing B very ductile. Even Mo which has high oxygen contents (100 ppm) can be worked at a relatively low temperature (800°C).View full abstractDownload PDF (2854K) -
Zen-ichi Tanabe1966 Volume 30 Issue 3 Pages 237-241
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSStress corrosion cracking is a failure that results from the simultaneous effect of stress and certain corrodants.
Many reports for stress corrosion cracking have been published, with various suggestions for its mechanisms. But no definite process has been established.
This paper describes a study on stress corrosion cracking of 70-30 brass exposed in ammoniacal copper sulfate solution at various potentials and pH values. The results indicate that the process is governed by reduction reactions from Cu(NH3)4++ to Cu2O which forms a surface film on the alloy, and selective corrosion susceptibility. Therefore, the process of stress corrosion cracking depends upon the presence of ammonia, redox potential and pH of corrodants.View full abstractDownload PDF (988K) -
Toranosuke Komata, Katsumi Ishihara, Mituo Tanaka1966 Volume 30 Issue 3 Pages 241-246
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of cold working and heat-treatment on the superconducting critical current of Nb-Zr wires containing about 10 wt%Zr have been studied. Samples were electron-beam melted and forged at temperatures between 900° and 1150°C, and cold drawn into 0.25 mm diameter wires. The cold workability of this alloy is so good that we could draw 10 mm diameter rod into 0.25 mm diameter wire without any intermediate heat-treatment.
Superconducting critical currents, Ic1, of short wire samples were measured as functions of applied vertical magnetic fields, H, up to 20 kilo oersteds at 4.2°K. The results show that Ic of Nb-10%Zr wire increases with increasing cold work, but that the improvement on H-Ic characteristics of the wire by heat-treatment is very small as compared with Nb-33%Zr wire.View full abstractDownload PDF (1481K) -
Yoshio Kamata, Shinya Chikamatsu1966 Volume 30 Issue 3 Pages 246-250
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe presence of Ti-compounds with N2 and O2 gases in the molten Alnico magnet alloy containing Ti was supposed to refine the alloy crystals. However, since densities of these Ti compounds are lower than those of the molten Alnico alloys, there seems to be the tendency to rise to the molten surface. In effect, however, these compounds are observed in large quantities in the molten Alnico alloy with Ti involves a probably due to the high viscosity of the molten alloy under the existence of Al. The viscosity of Alnico 8 with the variation of Ti and Al contents, or S addition effective for the columnization of the alloys are investigated in this paper. As a result, the viscosity of molten base alloys (Fe,Co,Ni,Cu) tended to increase in direct proportion to Al contents, and that at 7% and 8%Al corresponds to about 0.035 poise, about 2.3 times that of the Al free base alloy. With increase of the Ti addition, the maximum corresponding to 0.071 poise exists at 2%Ti and decreases with further Ti addition. The viscosity at 7%Al and 5%Ti corresponds to about 0.05 poise. The boundary between the equi-axial and the columnar regions, indicated by Wright et al., has a close bearing upon the alloy viscosities with Ti. Within the range of Al and Ti contents corresponding to less than 0.04 poise, the columnization is possible. S additions after Al and Al, Ti additions lower the viscosity almost in the same way as the Al free base alloy. Such complicated viscotity variations after Al, Ti and S additions are considered due to the transformation of alumina and Ti compounds changes in the volume ratio of these compounds.View full abstractDownload PDF (1218K) -
Naokatsu Tsuda1966 Volume 30 Issue 3 Pages 251-257
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the previous report was described the presence of three modes of grain growth, i.e. overall grain growth, zoned structure, and simple grain growth, in the grain growth of pure lead subjected to bending and its mechanism.
In the present study, the pure lead samples, which contained about 0.1% each of tin, bismuth, or cadmium and extruded into square rods of different grain sizes, were given 2, 4 or 6% bending strain at bending temperatures of 0° or 30°C, and then heated for an hour at 100°C. The progress of grain growth in the samples was examined, and an investigation was made on the relationship between the initial grain size and the grain growth rate, and also on the effects of tin, bismuth, or cadmium added to pure lead. The results were as follows:
(1) When tin or bismuth was added to pure lead, there were observed, as in pure lead, three modes of grain growth, namely, overall grain growth, zoned structure, and simple grain growth. When cadmium was added, there were observed the zoned structure and simple grain growth; but, under 2% bending strain, even the zoned structure was not observed.
(2) The overall grain growth and zoned structure of the tin- or bismuth-containing sample and the zoned structure of the cadmium-containing sample occurred when their initial grain size before bending was much smaller than that of pure lead.
(3) The grain growth rate was large when the initial grain size was small.View full abstractDownload PDF (1897K) -
Tadamichi Takei, Haruo Shimada1966 Volume 30 Issue 3 Pages 258-263
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe method for the electrolytic isolation of carbides and nitrides from 18%Cr, 8%Ni, 0.09%C austenitic and 17%Cr, 0.11%C ferritic stainless steels, and the precipitation behaviors of the carbides and nitrides in the latter steel under heat treatment have been studied. The results obtained are as follows:
(1) For the isolation of carbides from the austenitic stainless steel, the electrolyte consisting of 5% (vol) HCl, 95% (vol) methyl alcohol and 36 g zinc chloride is most suitable. The alcoholic iodine method used in place of electrolysis is also favourable in this case.
(2) For the isolation of carbides from the ferritic stainless steel, the electrolyte consisting of 3% (vol) HCl, 97% (vol) methyl alcohol and 36 g of zinc chloride is best fitted. The nitrides can be isolated simultaneously in this case.
(3) The precipitation of the carbides and nitrides from the quenched ferritic stainless steel does not occur at the temperatures over 1000° or under 500°C.View full abstractDownload PDF (1931K) -
Hideo Kaneko, Taiji Nishizawa, Akira Chiba1966 Volume 30 Issue 3 Pages 263-269
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe structure, composition and internal relations of borides and carbides in the system of Fe-B-C have been clarified by the electrolytic isolation, X-ray diffraction and other methods. The results obtained were as follows.
(1) The equilibrium diagram of Fe-B-C was composed. In this system there were four primary crystals, Fe2B, Fe3(C,B), γ-Fe and δ-Fe.
(2) Boride and carbide phases existing in equilibrium with α-Fe at 700°C were Fe2B, Fe23[B,C]6 and Fe3(C,B), while those existing in equilibrium with γ-Fe at 950°C were Fe2B and Fe3(C,B). This means that the ternary compound Fe23[B,C]6 is unstable at high temperature. However, if trace amounts of Cr or Mo were added to Fe-B-C alloys, Fe23[B,C]6 could be stabilized and existed as a stable, phase even at a temperature near 950°C.
(3) The nature of “boron-constituent”, which had been found in boron-steel, was also discussed from the result of examination on the austenite single phase region in the ternary system of Fe-B-C. And it was shown that the “boron-constituent” might be boro-cementite, Fe3(C,B), formed at the austenite grain boundaries.View full abstractDownload PDF (1202K) -
1966 Volume 30 Issue 3 Pages 269
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPlease see pdf. Wrong:[in Japanese] Right:[in Japanese]View full abstractDownload PDF (20K) -
Tatsuo Maekawa, Bunpei Ishii1966 Volume 30 Issue 3 Pages 270-274
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe breakaway oxidation, mainly at 850°C, of 2.5% tin-zirconium alloy in oxygen has been investigated by thermogravimetric measurements, electron microscopic observations, electron-probe microanalysis and X-ray diffraction studies. On the post-breakaway stage, the oxidation kinetics was largely dependent on the pressure of oxygen, and the significant cracking of the oxide film was observed. The electron-probe microanalysis and X-ray diffraction studies indicated that the tin in the alloy was precipitated as the intermetallic compound of ZrSn at the oxide/metal interface, and suggested that the oxide film has a multilayer structure consisting of ZrO2 and (ZrSn)O2 layers. The mechanism of the heavy breakaway phenomena of tin-zirconium alloy at high temperature was discussed on the basis of the behavior of tin in the alloy, and it was concluded that stress betweeh the layers of ZrO2 and (ZrSn)O2 induced the cracks of the oxide film and permitted the increased oxidation.View full abstractDownload PDF (1714K) -
Hiroshi Ikawa, Shinzaburo Ônishi, Akira Kondo, Sadao Doi1966 Volume 30 Issue 3 Pages 274-279
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBrittleness is sometimes seen in the tray of the heating furnace made of low Ni-Cr cast irons during operation. In connection with the above phenomenon, the thermal expansion, growth, resistance to oxidation and microstructure which are the basic properties of low Ni-Cr cast irons have been studied.
The results obtained are as follows:
(1) Plain cast iron which contains neither Ni nor Cr is most inferior in thermal expansion, growth and resistance to oxidation, respectively.
(2) The thermal expansion becomes considerably smaller as the Cr content increases. On the contrary, the thermal expansion increases with increasing Ni content.
(3) The growth rate becomes clearly lower, as the Cr content increases.
(4) Resistance to oxidation is improved, as the Cr content increases. And when the Ni content is low, the resistance to oxidation is good.View full abstractDownload PDF (1668K) -
Ryohei Tanaka, Akio Fujihira1966 Volume 30 Issue 3 Pages 279-284
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDilatometric measurement was performed at 650°C for the study of graphitization of structural steel containing 0.24%C, 1.18%Si and 2.03%Ni, pre-quenched from 700° to 1020°C. The rates of the grahitization process determined by chemical analysis and dilatometric and hardness measurements showed a good agreement within the range of experimental errors. Pre-quenching treatment had a complex effect on the graphitization rate: When the graphitization rate, given by the time required for 50% proceeding, was plotted against the pre-quenching temperature, there were two peaks. The main-peak was at the temperature just above Ac1 and the subpeak in the vicinity of Ac3. In the specimens pre-quenched from the temperature above Ac1, the incubation period of graphitization was always observed, and the graphitization nuclei were formed in the martensite region. On the other hand, in specimens pre-quenched from below Ac1, graphites were found only in the ferrite region. It was suggested by the experiment that the fastest graphitization rate attained by pre-quenching from Ac1 was due to the facilitation of graphite nucleation by carbon diffusion and recrystallization which were promoted by the enrichment of carbon and by internal stresses in the martensite.View full abstractDownload PDF (1950K) -
Yûnoshin Imai, Masao Izumiyama, Tsuyoshi Masumoto1966 Volume 30 Issue 3 Pages 284-290
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe phase transition in α solid solution by aging in the temperature range corresponding to the 475°C embrittlement was investigated using a number of Fe-Cr alloys. The calculation based on the statistical thermodynamics showed the existence of a miscibility gap below the σ region in the equilibrium diagram. That is, the alloys aged within this gap should separate into Cr-rich and Fe-rich α solid solutions. This was supported by the results of magnetic and electro-chemical measurements of the aged alloys.View full abstractDownload PDF (2475K) -
Yunoshin Imai, Hiroyuki Kagawa1966 Volume 30 Issue 3 Pages 290-296
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe mechanical properties of the tufftrided thin plates of low carbon steel (S 15 CK) and soft iron were investgaited by varying tufftriding conditions and tempering conditions after tufftride. The results obtained are summerized as follows:
(1) The strength of the plate specimens was improved by tufftriding; for example, in the case of 0.1 mm in thickness, yield and tensile strengthes of S 15 CK and soft iron were about 58 and 65 kg/mm2, and 65 and 78 kg/mm2, respectively.
(2) During tempering after tufftriding, precipitation of Fe4N was observed in the diffusion layer at about 250°C, and the precipitates began to resolve above about 300°C. The changes in hardness, yield point and tensile strength with tempering were in association with the behavior of Fe4N.
(3) The fatigue strength increased with increasing time duration and temperature for tufftriding. It was concluded that the increase in fatigue strength would be due to an increase in strength of the inner diffusion layer than that of the compound layer at the surface.View full abstractDownload PDF (2629K) -
Takeji Hachisuka, Tomio Nishimura, Masao Kond\={o}1966 Volume 30 Issue 3 Pages 296-301
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTo investigate the oxidation behavior of TiC-base-alloys containing molybdenum, TiC-10Ni and TiC-10Ni-(2.5∼18.57) Mo alloys were prepared by sintering. These alloys were exposed in still air at 600°∼1300°C. The oxidation process and the effect of molybdenum on oxidation were studied by weight gain, surface recession, X-ray diffraction and microstructure observation of scales. The following results were obtained.
(1) Addition of molybdenum to TiC-10Ni alloy increased the weight gain due to oxidation below 1100°C, which was most effective at 700°∼800°C. This effect was, however, decreased at higher temperatures and at 1300°C molybdenum increased in oxidation resistance reversely.
(2) From the results by X-ray diffraction, it appeared that at higher temperatures oxidation of molybdenum was suppressed to cause the appearance of metallic molybdenum in the scales and NiO·TiO2 was also increased, while at lower temperatures NiO was combined preferentially with NiO·MoO3 and decreased NiO·TiO2 content in the surface layer of scales.
(3) From measurements of the surface recession, it was found that the progress of oxidation of all alloys at 1000°C was parabolic and the parabolic rate constant increased in proportion with the molybdenum content. But at 1300°C, the surface layer of scales became porous and no parabolic relation was found in all the alloys.View full abstractDownload PDF (1373K) -
Seiichi Nishikawa, Kazuo Nagata, Shigeyoshi Kobayashi1966 Volume 30 Issue 3 Pages 302-307
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe processes of precipitation in Cu-Cr binary alloys with 0.05∼0.91 wt%Cr have been investigated by electrical resistivity, hardness and transmission electron microscopy, with the following results:
(1) Increase in electrical resistivity due to clustering of solute atoms or zone formation is not detected at above/300°C.
(2) Rapid decrease in electrical resistivity which may result from the annealing of quenched-in lattice defects is observed in all the specimens aged at 300°∼350°C for about 10 sec. The amount of this decrement decreases as the ageing temperature rises. This phenomenon is most prominent in the specimen with 0.30%Cr which is just the solubility limit at the solution temperature of 950°C.
(3) The difference of quenching conditions exerts influence on the electrical resistivity until the later stage of aging.
(4) The contrast in transmission electron microscopy shows the nucleation and growth of Cr rich precipitates in the specimens aged at 500°C, but the structure of which can not be determined in the present electron diffraction study.View full abstractDownload PDF (1599K) -
Mutsuo Ichihara, Seiichi Kakuwa1966 Volume 30 Issue 3 Pages 307-312
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSStudy on surface defects which develop during gas-carburizing has been made by the use of an optical microscope, electron microscope and electron microprobe X-ray analyzer.
These surface defects resulting from gas carburizing and hot-bath quenching range generally from 10 μ to 15 μ in depth. The metallographical study shows that this defective layer consists of oxides precipitated in the grain boundary, and the surrounding troostitic layer structure. Carburizing always causes precipitates to develop, to some extent, in the grain boundary. However, the depth of the softer layer varies depending upon the cooling rate in the quenching process. When water quenching or cold-oil quenching is employed, there develops practically no softer layer, whereas in the case of quenching in the 150°C-oil or 250°C-salt bath a distinct softer layer appears.
The tests with the aid of the electron microprobe X-ray analyzer reveal abnormal increases, on the surface, of such alloy elements as Mn, Cr and Si, their amounts reaching over 30% in the precipitates in the immediate vicinity of the grain boundary, while decreasing in the neighboring areas. The scanning pictures of surfaces demonstrate that the grain boundary contains a large amount of oxygen, giving evidence of the grain-doundary precipitates to be oxides of Mn, Cr, Si, etc.View full abstractDownload PDF (2268K)
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