Journal of the Japan Institute of Metals and Materials
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
Volume 31 , Issue 3
Showing 1-21 articles out of 21 articles from the selected issue
  • Yukiaki Hara, Masayasu Sugata, Toshio Aida, Shin-ichi Kondo
    1967 Volume 31 Issue 3 Pages 207-212
    Published: 1967
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Some investigators(5)∼(11) have proposed that two steps should be considered with regard to the reduction kinetics of the iron oxide pellet. One is the chemical reaction at the interface between the reduced and unreduced layers and the other is the gaseous diffusion through the reduced layer. A new method of analysis of the experimental data in the mixed-control mechanism of the above two steps was devised. The hypothesis that the reaction proceeds topochemically is adopted and the time required for 87.5% reduction which is one-half of complete reduction and the time for 50% reduction are utilized in this new method. By using the above two time values obtained experimentally, the chemical reaction constants and the intraparticle diffusion coefficients are briefly calculated by Eqs. (8)∼(12). Especially, in the case where the produced gas retards the reaction by its adsorption on the reacting surface, the analysis is possible by use of such a counting chart as Fig. 3 which is made out from the numerical calculation employing the retarding function.
    Hematite and magnetite pellets prepared from the Brazillian ore were reduced with hydrogen at low temperatures (500°, 550°C) and the decreases in the weight were measured by a thermobalance. The results are listed in Table 2. This method is simpler than the previous ones.
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  • Isoshi Kawashima, Kenzi Tokiwa
    1967 Volume 31 Issue 3 Pages 213-218
    Published: 1967
    Released: April 04, 2008
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    In a previous work the accuracy of the X-ray fluorescent method by the loose powder technique for eight elements (MgO, Al2O3, SiO2, P, S, CaO, MnO and T.Fe) in basic open hearth slags was compared with that by the briquet technique. The calibration curues on fifteen elements (MgO, Al2O3, SiO2, P, S, K2O, CaO, TiO2, V2O3, Cr, Mn, T.Fe, Cu, As and ZrO2) in iron ores, refractory bricks, and slags were prepared by using forty-six NBS, BS and homemade standard samples of iron ores, refractory bricks, slags and glasses by the ethylcellulose-briquet technique. The results showed that each element could be determined with the mean deviation of 0.001% to 3.40% in the concentration range up to 100%. The influence of the coexisting elements on the determination of each element was discussed.
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  • Tokuzou Tsujimoto, Hisaoki Sasano, Masao Adachi
    1967 Volume 31 Issue 3 Pages 218-222
    Published: 1967
    Released: April 04, 2008
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    Some of the present authors have investigated the effects of heat treatment and structure on the mechanical properties of Ti-2∼8%Al-2∼8%Co ternary alloys. In view of the forgeability and mechanical properties, Ti-8%Al-4%Co alloy was singled out from these alloys and forged bars were prepared from an ingot of 60 kg. In this report, the microstructure and the mechanical properties at room temperature of Ti-8%Al-4%Co alloy for various heat treatments were investigated.
    The results obtained are as follows: (1) This alloy has good forgeability. (2) The alloy quenched from above 800°C and from 750°∼700°C has the α+β and the α type structure, respectively. (3) For room temperature use, the α+β structure has a good combination of strength and toughness. (4) In the alloy quenched from above 800°C followed by aging at 450°C, the tensile strength increases and the toughness decreases.
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  • Tokuzou Tsujimoto, Hisaoki Sasano, Masao Adachi
    1967 Volume 31 Issue 3 Pages 223-227
    Published: 1967
    Released: April 04, 2008
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    Ti-8%Al-4%Co alloy can be expected to have good mechanical properties at high temperatures because of its high aluminium content. At first, the effect of heat treatment on the creep-rupture properties was investigated. From the results, the heat treatment, i.e., quenching from 700°C, was selected for high temperature use. Then tensile, creep-rupture and fatigue properties at high temperatures were investigated.
    The results are as follows:
    (1) Up to 500°C in testing temperature, the tensile strength at elevated temperature is slightly affected by testing temperature, and over 500°C it decreases markedly. The tensile strength at 500°C is 82.5 kg/mm2.
    (2) Above 460°C the crrep-rupture strength is lower than the fatigue strength and below this temperature the latter is lower. The creep-rupture strength for 1000 hr is 32 kg/mm2 at 500°C and decreases linearly between 400°C and 600°C. The fatigue strength for 107 cycles is 47.4 kg/mm2 at 400°C and hardly varies below 400°C.
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  • Tomomi Mizuno, Tetsuo Matsumura
    1967 Volume 31 Issue 3 Pages 227-232
    Published: 1967
    Released: April 04, 2008
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    A spectrographic method has been developed for the simultaneous determination of chromium, iron, nickel and tin in zircaloy-2. Analyses were made on samples in the form of solid machined specimens 30 mm in diameter. Spectra were excited with a low voltage spark (multisource type) in argon atmosphere and recorded on a photographic plate with the Ebert mounting spectrograph. Zirconium was used to serve as the internal standard.
    Various kinds of counter electrodes, such as graphite, silver, copper, aluminium, zinc, tungsten and iron, were investigated. The effects of them on the results were small enough in an optimum analytical condition.
    Precision of the presented method was 3∼7% in coefficient of variation and the method was accurate enough to be utilized to check compliance with specifications.
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  • Shozo Yoshioka, Yutaka Nakayama, Taichiro Ito
    1967 Volume 31 Issue 3 Pages 233-237
    Published: 1967
    Released: April 04, 2008
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    The dislocation distribution and arrangement in Cu-2.5 at%Al, Cu-5 at%Al, Cu-10 at%Al and Cu-15 at%Al single crystals deformed into stage I and stage II were studied by means of the etch pit technique. Etch pit observation was made on the surface of the (1\bar1\bar1) plane, and also on the planes cut parallel to the (11\bar1) and (111) planes of each specimen. The etch pits on the (111) and (1\bar1\bar1) planes gave information on the primary (11\bar1) dislocations, and those on the (11\bar1) plane, on the secondary dislocations.
    Dislocation distribution on the (111) plane of Cu-2.5 at%Al was rather regular in stage I and became long concentrated dislocation arrays in stage II. On the (11\bar1) plane a cell structure formed in stage II.
    Dislocation distribution on the (11\bar1) for Cu-5 at%Al was similar to that of Cu-2.5 at%Al but the slip direction was clearer in the former. From the etch pit arrays on the (11\bar1) cut plane it became possible to distinguish the plane to which etch pit arrays belong. For Cu-10 at%Al and Cu-15 at%Al, deformation proceeded due to the widening of primary slip bands, and in the region between the slip bands no dislocation multiplications were observed. From the observation on the (11\bar1) plane it was found that dislocations which belong to the (1\bar1\bar1) plane were observed at the early stage of stage I, but the dislocations which belong to the (1\bar11) and (111) planes were multiplied where the stress-strain curve entered into the transition region from stage I to stage II. And they were observed at the restricted areas. From these experimental results it was assumed that the Lomer-Cottrell dislocations formed by interaction between (11\bar1) and (1\bar11) or (111) dislocations would be related to the transition of the stress-strain curve from stage I to stage II.
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  • Shozo Yoshioka, Yutaka Nakayama, Taichiro Ito
    1967 Volume 31 Issue 3 Pages 238-242
    Published: 1967
    Released: April 04, 2008
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    Dislocation densities in deformed Cu-2.5 at%Al, Cu-5.0 at%Al, Cu-10 at%Al and Cu-15 at%Al were measured by counting etch pits on the {111} plane. The relation between the dislocation density and some of the physical properties were studied.
    The results obtained were as follows:
    (1) The dislocation density increased proportionally with strain in stage I. In stage II the same relation was obtained, though the increasing rate of dislocation density was larger.
    (2) The dislocation density on the (111) plane was higher than that on the (11\bar1). Dislocation densities on these two planes became similar with increasing strain. In Cu-2.5 at%Al dislocation density on the two planes were of the same order at the beginning of the stage II, but in Cu-15 at%Al there was a larger difference in dislocation density even at the largest stress measured.
    (3) In stage I the dislocation density was proportional to stress. In stage II the square root of dislocation density was proportional to stress. This relation holds not only for the primary dislocation density but also for the secondary dislocation density.
    (4) In the equation τ=αGbN1⁄2, α∼0.65 was obtained for all the Al concentrations examined.
    (5) The rate of strain hardening in stage I was found to be proportional to the increasing rate of dislocation density for all the specimens.
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  • Taichi Kamijo
    1967 Volume 31 Issue 3 Pages 243-247
    Published: 1967
    Released: April 04, 2008
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    The purpose of this paper is to account for the derivation of the drawing textures, assuming that the stress system in drawing is a multiaxial one, i.e. a tensile stress in the direction of drawing together with a circular array of compressive stresses perpendicular to this direction. When a tensile stress axis is denoted by a certain point in the basic unit stereographic triangle, there are compressive stresses operative at every point on the great circle normal to the tension axis.
    Each slip system is supposed to operate in proportion to the length of a region bearing the highest resolved shear stress along this great circle. The wire axis is considered to displace towards the operative slip direction by the tensile stress and to rotate away from the normal of operative slip plane by the compressive stresses. The tension rotation of the wire axis is composed of every rotation due to the operation of more than three slip systems. Then, the resulting rotation of the wire axis is assumed to be described by combining the tension rotation with the compression rotation like vectors.
    In the case of fcc metals the wire axis tends to rotate towards [111] or [001], if it lies within a triangle [011]-[111]-[113] and [001]-[011]-[113] respectively. Thus a double fibre texture will result having [111] and [001] as fibre axes. Since the slip rotation due to cross slip causes the wire axis to move towards [111], a single [111] fibre texture will develop in aluminium wire with a large stacking fault energy.
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  • Meguru Nagamori, Mitsuo Kameda
    1967 Volume 31 Issue 3 Pages 248-254
    Published: 1967
    Released: April 04, 2008
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    In order to establish the relations between the sulphur activities and the compositions of pyrrhotite (FeS1+x), the equilibrium measurements were carried out with the aid of the gaseous mixture of H2-H2S. The equations that relate the gas composition at room temperature to that at high temperature were derived thermodynamically by considering the species of S2 and HS besides H2 and H2S. The experimental results permit to calculate the activities of sulphur, iron and FeS, ΔGT0 of the formation of stoichiometric FeS, the heat and the entropy of mixing in pyrrhotite. The statistical thermodynamics of imperfect crystals was then applied tentatively to the system for interpreting the activity-composition relations in pyrrhotite.
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  • Hakaru Masumoto, Takeo Kobayashi, Kiyoshi Watanabe
    1967 Volume 31 Issue 3 Pages 254-258
    Published: 1967
    Released: April 04, 2008
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    Since the present investigators found a new magnet alloy “Malcolloy” of high coercivity in the system of cobalt and aluminium, they have carried out studies on the effect of additions of nickel, molybdenum, titanium, vanadium and chromium on its magnetic properties and obtained the highest coercive force of 1600 Oe. Further, they have investigated the effect of the addition of tungsten on the permanent magnet properties of Co-Al alloys and discovered that the addition of tungsten increases the coercive force of the binary alloys. The alloy which exhibits the highest coercivity has the composition of 75.89%Co, 13.55%Al and 10.56%W and shows the coercive force of 1450 Oe, the residual magnetic flux density of 3100 G and the maximum energy product of 1.40×106 G Oe when tempered at 525°C for 150 hours after water quenching from 1380°C. These alloys consist of many ferromagnetic elongated particles about 350 Å in diameter which are dispersed in the matrix of nearly non-magnetic β′ phase. Consequently, it may be concluded that the high coercivity of these alloys is mainly caused by the presence of the fine particles of a single magnetic domain.
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  • Hakaru Masumoto, Takeo Kobayashi, Kiyoshi Watanabe
    1967 Volume 31 Issue 3 Pages 259-263
    Published: 1967
    Released: April 04, 2008
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    Since the discovery of a new magnet alloy “Malcolloy” having a high coercive force in the system of cobalt and aluminium, the present investigators have continued researches on the effect of additions of nickel, molybdenum, titanium, vanadium, chromium and tungsten on the properties of Malcolloy, the highest coercive force obtained in each system of alloys being 1450 to 1600 Oe. In this report the effect of manganese addition on the properties of Co-Al alloys was examined, with the result that the coercive force of the alloys decreases and the residual flux density increases gradually with increasing manganese content, and the maximum energy product shows the highest value in the alloy containing 84.59%Co, 12.81%Al and 2.60%Mn which exhibits a maximum energy product of 2.50×106 GOe, a residual flux density of 5900 G, and a coercive force 860 Oe, when tempered at 525°C for 20 hours after water-quenching from 1375°C. These alloys consist of many ferromagnetic elongated particles about 350 Å in mean diameter which are dispersed in the matrix of nearly non-magnetic β′ phase. Consequently, it is considered that the high coercivity of the alloy is mainly due to the presence of the fine particles of a single magnetic domain.
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  • Hakaru Masumoto, Hideo Saitô, Michio Kikuchi
    1967 Volume 31 Issue 3 Pages 263-268
    Published: 1967
    Released: April 04, 2008
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    The thermal expansion in the temperature range of 0° to 800°C, Young’s modulus in the temperature range of −50° to 300°C, rigidity modulus in the temperature range of 10° to 50°C and the mechanical strength at room temperature in a high elasticity alloy of F.C.C. type “Dia-flex” consisting of 38.0%Co, 22.4%Fe, 16.5%Ni, 12.0%Cr, 4.0%W, 4.0%Mo and small amounts of other elements were measured with the single crystals and annealed poly-crystals (in the predominant direction ⟨112⟩(1\bar10): Young’s modulus 23.00×105 kg/cm2, elastic limit 120 kg/mm2 and tensile strength 250 kg/mm2). Then, from the data obtained, the volume compressibility, the principal elastic parameters Sij, the principal elastic constants Cij, and Young’s modulus and the rigidity modulus in three principal orientations of the single crystals were calculated. From the result it has been known that Young’s moduli at 20°C are 11.68×105 kg/cm2, 22.49×105 kg/cm2 and 33.78×105 kg/cm2, and the rigidity moduli at 20°C, 12.01×105 kg/cm2, 5.93×105 kg/cm2 and 5.33×105 kg/cm2 respectively in the orientations of ⟨100⟩, ⟨110⟩ and ⟨111⟩ of the single crystals, showing high anisotropies of elastic moduli. The anisotropy of the temperature coefficients of elastic moduli is also very high.
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  • Hisasuke Takeuchi, Sadami Tomita, Tadatoshi Toda, Koukichi Ouhata
    1967 Volume 31 Issue 3 Pages 268-274
    Published: 1967
    Released: April 04, 2008
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    The authors observed the welding tendency of electrical contact materials by means of measuring the strength of welding which was caused at the contact by passing a large current through the stationary contact to be tested. The critical welding current of a contact material was defined as one below which no welding occurred. Further an attempt was made to find materials having a high critical welding current, other wise, materials having a small welding strength when welding cannot be avoided. The results of experiments were summarized as follows.
    (1) Assuming the critical welding current of copper contact as 1, the value of Cu-Pb or Cu-Bi alloys contact was as high as 1.2 to 2.0. Thus, it was concluded that copper alloys alloyed with low melting point elements possessed an excellent non-welding tendency.
    (2) Sintered silver-carbon and silver-carbon-cobalt materials showed a high critical welding current. A large value of the critical welding was obtained by use of a pair of contacts being composed of different kinds of alloys, e.g. silver and cobalt-carbon alloy.
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  • Hisasuke Takeuchi, Koukichi Ouhata
    1967 Volume 31 Issue 3 Pages 274-278
    Published: 1967
    Released: April 04, 2008
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    In the course of developing new series of contact materials, a standard testing apparatus was constructed after ASTM B-182-49. Using pure silver contact, measurement were made on the number of welds formed, contact resistance, temperature rise and weight loss during and after a series of make-and-break cycles.
    It was found that the tendency of electrical contacts to weld was affected by various factors characteristic of the testing apparatus, i.e., closing and opening speeds of contacts, vibration of the apparatus and chattering of contacts, the latter being markedly influenced by the closing force and momentum of the moving arm.
    For these and other reasons, a modified apparatus was constructed using photo-transistors and obtained a much more satisfactory results than the standard one.
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  • Yoshio Baba
    1967 Volume 31 Issue 3 Pages 279-283
    Published: 1967
    Released: April 04, 2008
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    Experiments were carried out to investigate the influence of third addition elements such as Li, Be, Mg, Ca, Ti, V, Co, Ni, Ge, Mo, Cd, In, Sn, Sb, Pb, and Bi on the formation of G.P.zones in Al-2.5 at%Zn alloys.
    The results are as follows:
    (1) Ca, V, Mo, Ni, Co and Ti amounting to less than 0.2 at% do not interact with G.P. zones of Zn atoms, but decrease the rate of formation of the G.P.zones. This effect is similar to that of Fe, Cr, Mn or Zr, and it can be reasonably explained in terms of the increase in density of dislocations and in boundary area by the grain refining and the existence of these insoluble compounds which could act as effective sinks to cause the decrease in concentration of quenched-in vacancies.
    (2) Sn(≤0.1 at%) and Ge(≤0.2 at%) also do not interact with G.P.zones of Zn atoms, but these solute atoms, especially Sn decrease remarkably the rate of formation of the G.P. zones. This effect is similar to that of Si, and it could be interpreted from the fact that the binding energy between the solute atoms and vacancies is greater than that between Zn atom and vacancy.
    (3) Be, Mg, Cd and In decrease the rate of formation of the G.P.zones in an equal degree to or more than Ge. It is clear that Mg and Be atoms in the amount of more than 0.03 at% interact with Zn atoms and participate in the G.P. zones. Moreover, from the results of age-hardening for a long period, it seems that Cd atoms more than 0.03 at% also have interaction with G.P.zones of Zn atoms. Thus, the rate of clustering will be affected by the mobility of solute additions/Zn/vacancy groups as well as the magnitude of the binding energy between the solute atoms and vacancies.
    (4) Pb and Li decrease slightly the rate of formation of the G.P. zones. This may be mainly due to a little larger binding energy between Pb or Li atom and vacancy than that between Zn atom and vacancy, although the clustering of Li atoms themselves and the interaction between Li clusters and Zn atoms must also be taken into consideration. From this experiment, it is not clear whether Sb and Bi have influence on the formation of the G.P. zones.
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  • Hisashi Ito, Tsutomu Yanagase, Yukio Suginohara, Nobuyoshi Miyazaki
    1967 Volume 31 Issue 3 Pages 284-289
    Published: 1967
    Released: April 04, 2008
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    The electrical conductivity of molten lead silicates containing one of various fluorides as a third component has been measured in order to make clear the effect of fluorides on the structure of molten slags.
    The four-terminal method was used for the electrical circuit, comparing a potential drop across the cell with that of the standard resistor by means of a cathode ray osillograph.
    According to the results obtained, the conductivity increases with increasing temperature and fluoride content. In the acid melts, the conductivity contribution of fluoride is more than that of oxide at equimolar composition, but not remarkable in basic melts. When fluoride is added to the silicate melts, the following reaction may be considered to take place: 2MF_2+SiO_2=2MO+SiF_4.
    From the result of experiment as well as the calculation of free energy change of the above reaction, an appreciable amouut of SiF4 is found to produce, when PbF2 and AlF3 are used. The mechanism of increasing conductivity when fluorides are added to silicate melts is also discussed.
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  • Hisashi Ito, Tsutomu Yanagase, Yukio Suginohara, Nobuyoshi Miyazaki
    1967 Volume 31 Issue 3 Pages 290-295
    Published: 1967
    Released: April 04, 2008
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    The studies on infrared absorption spectra have been carried out for the purpose of elucidating the effect of fluorides on silicate melts. The samples were prepared by melting the silicate containing one of various fluorides in a platinum crucible and then cooling rapidly to obtain glassy silicate. For the crystallized silicate, the heat treatment of glass was applied at appropriate temperature. The KBr disc method was employed for the infrared absorption spectra.
    The results indicated that between acid and basic melts there was no difference in the effect of fluoride on the silicate structure.
    The shift of the maximum absorption band due to the stretching vibration of Si-O bond (ν3) is apparently smaller in the vitreous silicate containing the fluoride than that observed in the case of addition of an equimolar oxide.
    According to the X-ray diffraction patterns of crystalline silicate with fluoride, no new compound was obserbed, but the silicate compounds and added fluoride were found.
    In the present experiment, the absorption band due to the Si-F bond was not observed. The absorption bands of 764 cm−1 in Na2O-SiO2-NaF and 857 cm−1 in CaO-SiO2-CaF2 were proposed by Kumer et al. to be due to the existence of the Si-F bond in the silicate. These may be attributed to the characteristic bands of the crystalline Na2O·2SiO2 and 3CaO·2SiO2, respectively.
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  • Akinori Muta, Gyozo Toda, Haruya Shimanoki
    1967 Volume 31 Issue 3 Pages 296-300
    Published: 1967
    Released: April 04, 2008
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    A new surface hardening method using B4C-NaOCN has been developed. According to the new method, the steel specimen is immersed into a NaOCN bath (560°∼570°C) to from thin film of NaOCN on the surface of the specimen, and the specimen is then embedded in B4C powder and heated in a closed air furnace at 900°∼1100°C. This method can be successfully applied to the surface hardening of pure iron, plain carbon steels and alloy steels.
    The thickness of the boronized surface layer is 0.1∼0.3 mm and depends on the treating time and temperature, especially the temperature: The Vickers hardness is as high as 1400∼1800 for the specimen heated for 5 hr at 1000°C: The wear resistance is quite good and the corrosion resistance to H3PO4 and H2SO4 is as good as cemented carbide alloys. However, the corrosion resistance to HCl, HNO3 and H2O is not so much improved as compared with the non-boronized steel. The boronized layer consists of FeB and Fe2B, and a comb-shaped figures at the interface between the boronized layer and mother alloy are observed.
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  • Katashi Masumoto, Shigehiro Isomura
    1967 Volume 31 Issue 3 Pages 301-302
    Published: 1967
    Released: April 04, 2008
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  • Katsuya Kudaka, Hiroshi Konno
    1967 Volume 31 Issue 3 Pages 302-303
    Published: 1967
    Released: April 04, 2008
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  • Iwao Hagiwara, Tadayoshi Takahashi, Toshimasa Sakamoto
    1967 Volume 31 Issue 3 Pages 303-304
    Published: 1967
    Released: April 04, 2008
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