All issues
Volume 32, Issue 1
Displaying 1-19 of 19 articles from this issue
- |<
- <
- 1
- >
- >|
-
Hiroshi Iijima, Kinya Inamoto1968 Volume 32 Issue 1 Pages 1-6
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt has been generally considered that sulfide corrosion cracking of steels is hydrogen embrittlement cracking, but it has not been confirmed clearly. Furthermore, few studies on the behavior of sulfer has been reported.
In the present study experiments have been made on the behavior of sulfide in the sulfide corrosion cracking using a radio-isotope of 35S: 80 kg high strength steel, 60 kg high strength steel, APS steel and boiler plate steel were used as specimens. These specimens were immersed in sulfide corrosive solution under stress for a long time. After this treatment, the distributions of 35S in these specimens were investigated by radiometry and an autoradiographic technique.
The experimental results are as follows:
(1) The more the susceptibility of the specimens to the sulfide corrosion cracking is, the greater the amount of 35S deposit. And 35S diffuses in such specimens more deeply.
(2) The distribution of induced crack corresponds almost exactly to that of 35S. Howevre, 35S cannot be detected in some cracks.
(3) The influence of stress on the sulfide corrosion cracking was confirmed.
(4) It is considered that sulfur diffuses into grain boundaries of steels.
It has been conclude that the sulfide corrosion cracking is different from simple hydrogen embrittlement cracking and stress corrosion cracking by anode attacks exerts influence on the sulfide corrosion cracking.
From the these points of view, the behavior and the role of sulfur in the sulfide corrosion cracking should be investigated with more keen interest.View full abstractDownload PDF (1955K) -
Kenzo Hijikata, Kiyoshi Mirumachi1968 Volume 32 Issue 1 Pages 7-10
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSRecently cemented carbides have been used in the field of chemical industry as a corrosion resistance material.
In this report the chemical resistance of cobalt-base cemented carbides against hydrochloric acid, sulfuric acid, nitric acid and citric acid are examined for 50 hr and 100 hr at room temperature and at 95°C, respectively. The results obtained are summarized as follows: The weight loss data indicate that the corrosion of cemented carbides is due to the disolution of cobalt as binder metal and the resistance against acids increases with decreasing cobalt content. The passive film formed on the surface of cemented carbides attacked by nitric acid suppreses the chemical reaction. The corrosion resistance of cobalt-base cemented carbides was comparable to that of Stellite, stainless steel and Hastelloy.View full abstractDownload PDF (1437K) -
Masaru Satoyoshi, Fusao Hayama1968 Volume 32 Issue 1 Pages 11-17
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAn experimental study has been made of the influence of oxides on the friction and wear characteristics of a hardened bearing steel. Such oxides as Fe2O3, Fe3O4, FeO, CuO, Cu2O and PbO, prepared by the sintering method, were slid against a hardened bearing steel ring of 75 mm diameter at a sliding speed of 1∼6 m/sec under an apparent pressure of 3 kg/cm2. The results obtained are as follows:
Iron oxides: The coefficient of friction of Fe2O3 and FeO on the hardened bearing steel was high, but that of Fe3O4 was lower. The difference in the wear of hardened bearing steel with mating oxides was not clarified, but rubbing with Fe3O4 at a low speed less wore the steel. Fe2O3 formed a flat surface on the steel. It was observed that FeO was oxidized to Fe2O3 in the friction process.
Copper oxides: Cu2O showed a high coefficient of friction and wore the steel, but formed a flat surface on it. It was found that CuO has good lubricating ability in dry friction due to the low friction and little surface damage of the steel.
Lead oxide: the coefficient of friction of PbO was low, and its change with increasing sliding speed was very small. No damage was observed on the surface of hardened bearing steel, owing to the formation of a solid film of PbO on the steel surface.View full abstractDownload PDF (2425K) -
Taichi Kamijo1968 Volume 32 Issue 1 Pages 17-21
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFor metals of low stacking fault energy, it appears that the amount of the (112)[\={1}\={1}1] texture component decreases with increasing rolling reduction owing to the normal slip rotation toward (111)[\={1}\={1}2] as well as the mechanical twinning that converts (112)[\={1}\={1}1] to (552)[\={1}\={1}5].
The resolved shear stress on the slip systems which rotate (112)[\={1}\={1}1] toward (111)[\={1}\={1}2] is lower than that of systems, leading to the rotation in the opposite direction between them. Hence the slip rotation away from (112)[\={1}\={1}1] to (111)[\={1}\={1}2] can be explained on the basis of latent hardening of slip systems.
The cause of latent hardening is considered to be the rocking of dislocations lying on the {111} plane which intersects the (111) plane roughly parallel to the rolling plane, because the width of stacking faults on the (111) plane is extended remarkably during rolling and plates of deformation twinsare formed along the (111) plane.
The rolling texture transition and the stacking fault energy dependence of the wire texture in fcc metals are considered to be due to the three superposed mechanisms, i, e., cross slip, mechanical twinning and latent hardening.View full abstractDownload PDF (1438K) -
Taichi Kamijo1968 Volume 32 Issue 1 Pages 22-28
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPolycrystalline copper with {011}⟨211⟩ is found to migrate toward an orientation near {123}⟨211⟩ after rolling more than 50 pct. This slip rotation is considered to be due to cross slip.
Analysis of slip rotation coccuring in rolling where slip systems bearing the highest resolved shear stress are assumed to operate leads to the conclusion that displacements toward {011}⟨211⟩ take place in the greater part of the standard projection.
Provided that extensive cross slip occurs on the way to {011}⟨211⟩, the normal to the rolling plane is expected to reach between ⟨011⟩ and ⟨123⟩ depending on the initial orientation and the amount of cross slip.
The {112}⟨111⟩ texture component will be formed by normal slip rotation, if the normal to the rolling plane and the rolling direction lie between ⟨001⟩-⟨111⟩ and ⟨110⟩-⟨112⟩ respectively and their vicinity.
{112}⟨111⟩ is considered not to be the most stable end position against slip rotation. However it can be a minor component of the pure metal type texture for metals of high stacking fault energy, since rotation away from {112}⟨111⟩ to {011}⟨211⟩ is retarded by extensive cross slip.
For metals of low stacking fault energy, the {112}⟨111⟩ component will decrease with increasing the amount of reduction owing to the three superimposed mechanisms, i.e., the conversion to {552}⟨115⟩ by mechanical twinning, the formation of {111}⟨112⟩ by latent hardening and the slip rotation toward {011}⟨211⟩. Consequently an alloy type texture composed mainly of {011}⟨211⟩ will develop.View full abstractDownload PDF (2230K) -
Mamoru Nakamura, Hitoshi Asamura, Kyuhiko Yamanaka1968 Volume 32 Issue 1 Pages 28-32
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis study was carried out to investigate the properties of martensite during tempering in hot worked and quenched carbon steels. Steels containing 0.1, 0.4 and 0.47% carbon were hot worked and quenched, and then tempered at 100°∼650°C for various time. From the hardness measurements (HRC or Hv), the hardness of the hot worked and quenched steels was higher than that of the unworked and quenched ones. The effects of hot working on the thermal dilatation were also tested by the differential method. It was found that the first stage of the tempering process in the severly hot worked and quenched steels appeared at temperatures about 30°C higher than that of the conventionally heat treated ones, and the total amount of contraction at 200°C was smaller than that of the conventionally heat treated ones. In hot worked and quenched steels, the contraction ratio at 400°∼600°C in the dilatation curves was smaller than that of the conventionally treated ones, and the amount of the contraction depended on the degree of hot working of austenite.View full abstractDownload PDF (1641K) -
Yukishige Fukase, Tsutomu Nishima, Koichiro Osozawa, Rikio Nemoto1968 Volume 32 Issue 1 Pages 33-38
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESS80Ni/20Cr alloys with or without additions of 0.05%La-Ce mish metal were oxidized at 1200°C by intermittent tests. Then, in order to clarify the mechanism of the effect of rare earth element additions on the oxidation resistance, the surface layers of the oxidized alloys were studied by means of X-ray diffraction, electron probe microanalysis, optical micrography and chemical analysis.The composition and the structure of the oxide formed were markedly influenced through the addition of rare earth elements: the surface oxide was composed of pure Cr2O3 oxide film and the internal oxidation of Si at the scale/matrix interface was promoted. This internal oxide, SiO2, provides a “locking” effect for the surface oxide and roots in the alloy acting as protective films. Any phases enriched in rare earth elements could be found neither in the oxides nor at the scale/matrix interface. It was considered, therefore, that the oxidation resistance of the alloy with addition of rare earth elements was not improved by the formation of rare earth oxide itself but rather by the formation of SiO2 at the scale/matrix interface.
It is concluded that rare earth elements improve the oxidation resistance through indirect effects, i.e. the acceleration of internal oxidation of Si and the formation of pure surface oxide, Cr2O3, during the heating and cooling cycles.View full abstractDownload PDF (2265K) -
Yukishige Fukase, Kazuo Ebato, Nobuhiro Okubo, Seiichi Murao1968 Volume 32 Issue 1 Pages 38-44
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSMechanical properties at ambient temperatures were studied in detail on metastable austenitic Cr-Ni stainless steels and the relations between their particularity and structural changes were discussed.
The metastable austenitic steels is strengthened by the occurrence of martensite during deformation and the increment in strength corresponds to the amount of martensite. Fracture elongation shows the maximum value at the temperature or the composition, at which the following two conditions are satisfied.
(1) A large amount of deformation is available in austenite before martensitic transformation.
(2) Once local contraction occurs, martensite is gradually induced and the increment in strength caused by this martensite is large enough to cancel the increment in stress at the spot where the local contraction takes place.
When the condition (2) is satisfied, plasticity is increased as well as strength. This phenomenon is attributed to the martensite induced during deformation and may be called “Transformation Plasticity”.
The stability of austenite is indicated with the temperature at which the maximum elongation is obtained.View full abstractDownload PDF (2387K) -
Kenichi Koizumi1968 Volume 32 Issue 1 Pages 45-49
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of low reduction rate (4.0, 3.0, 2.0, 1.5%) on the rolling texture of aluminum especially in the inner layer (about 1/10 of the thickness of the specimen) below the surface have been studied by measuring the intensities of diffracted X-ray and by taking the pole figures.
In this way, it was found that there were various points of difference as to the rolling textures which were rolled by these various reduction rates. At low reduction rates of 1.5 and 2.0%, the crystalgraphic texture of the (100)[011] orientation appeared more distinctly as the specimen was rolled down to 70%. When the amount of rolling exceeded 70% the orientation became unstable, and with 90% rolling, the orientation of the rolling texture was found to be about (110)[1\={1}2]+(112)[11\={1}]. At a reduction rate of 4.0% the crystalgraphic texture of the (100)[011] orientation appeared at the initial stage of rolling (about 40% reduction). As the specimen continued to be rolled, the orientation of about (112)[11\={1}] appeared at 70% reduction. At 90% reduction, the orientation of approximately (110)[1\={1}2]+(112)[11\={1}] was stronger at a higher reduction rate. It was also found that the average areas of grains in the surface layer of the plate were larger at a lower reduction rate. Thus it has been made clear that at a low reduction rate the rolling texture shows a peculiar behavior in the inner layer below the surface.View full abstractDownload PDF (2021K) -
Kunio Kusaka, Kazuo Ikushima1968 Volume 32 Issue 1 Pages 50-54
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSRecently the tetra ethyl lead has been used for the production of high octane gasoline of automobile engines. PbO formed by the combustion of leaded fuels corrodes exhaust valves severely and causes a number of faults. In order to study the exhaust valves with high corrosion resistance to PbO, the effect of alloying elements of 21Cr-9Mn-4Ni-0.4N type heat resisting steels was investigated. The testing procedure requires that a specimen of the alloy is exposured to molten lead oxide in an alumina crucible at an elevated temperature, 915°C or 1000°C, for 30 minutes. Then the weight loss per unit surface area of the specimen represents the corrosion tendency of the steel. The results obtained are as follows:
(1) The alloying elements which improve the corrosion resistance of 21Cr-9Mn-4Ni-0.4N type steels are Cr,Ni,Mn,Co and C. (2) P,W,Cu,Si and Al decrease the corrosion resistance. (3) N,V,B and Mo have no remakable effect on corrosion resistance.View full abstractDownload PDF (1615K) -
Ôhiko Kammori, Isamu Taguchi, Akihiro Ono1968 Volume 32 Issue 1 Pages 55-60
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPotentiostatic electrolysis with Na-citrate-KBr-electrolyte, potentiostatic electrolysis with FeCl3-ZnCl2-acetylacetone-electrolyte, direct extraction with acetylacetone, I2-n-butylalcohol extraction, FeCl3-n-butylalcohol extraction and acid extraction were studied for the isolation of 0.02∼1% of molybdenum carbide (Mo2C) from Fe-Mo-C steels tempered at 650°∼750°C for 1 hr. Molybdenum carbide (Mo2C) extracted from the steels was found to be unstable in water. The highest value and the best precision were achieved when the steels were extracted at room temperature with 30 N phosphoric acid. The following method was recommended for the quantitative extraction of molybdenum carbide (Mo2C).
One-tenth g of chipped sample is dissolved at room temperature with 50 mL of 30 N phosphoric acid. The extracted residue is collected through the Millipore filter (220 mμ) and washed by 30 N phosphoric acid. Molybdenum in the residue is determined by MIBK-extraction-thiocyanide-spectrophotometry and molybdenum carbide (Mo2C) is calculated.
The time required for the extraction was 15∼25 hrs and the time for molybdenum determination was about 1 hr.View full abstractDownload PDF (2190K) -
Akio Hara, Shuji Yazu1968 Volume 32 Issue 1 Pages 61-66
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt was considered that some braking phenomena against crack propagation should exist at high temperatures if the fracture of the cemented carbide at high temperatures was investigated from the point of view of crack propagation. The authors made a model experiment to study such phenomena. A WC-5%Co and a WC-6%Co alloy were used. An indentation was given by a Vickers hardness tester to a lapped surface of the specimen. From the corners of the indentation, four sharp cracks occurred. The specimens with cracks were annealed in a vacuum furnace over the temperature range 400° to 1200°C for 1∼15 min. The TRS value before and after annealing was measured, setting a pair of cracks perpendicular to the direction of maximum tension in the lower surface of the specimen. The change of the cracks by annealing was observed by a microscope. The results obtained are as follows: (1) The strength, which decreases greatly by giving sharp cracks, recovers by annealing even at 400°C and its amount increases with increasing annealing temperature. (2) The strength recovery is saturated in 1∼5 min. (3) The strength recovery is attributed to (i) the increase of the radius of curvature at the top of a crack which is induced by the gradual filling up of the crack due to the self-diffusion of cobalt and (ii) the effect of the partial disappearance of the cracks by heating above 1000°C. The degree of cobalt movement nearly coincides to the theoretically calculated value based on the sintering theory of Kuczynski.View full abstractDownload PDF (2615K) -
Mitsuru Uehara, Kazuo Yamakawa1968 Volume 32 Issue 1 Pages 67-72
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSMagnetic torque and rotational hysteresis measurements on iron and iron-cobalt particles, compacted at relatively high packing fraction, have been done to determine the induced anisotropy and the distributed local anisotropy. Arrangement of individual particles in the sample at magnetically oriented state and unoriented state were observed by means of electron microscope. The samples were prepared by electrodeposition into the mercury cathode.
Degrees of alignment of iron and iron-cobalt particles are saturated at the field of the order of 6000 oersteds and 7000 oersteds, respectively. These fields also are found to be in fair agreement with the maximum anisotropy field. The muximum anisotropy are explained by magnetization curling model. The mean anisotropy and its distribution of the sample are determined by the measurements of torque at an angle of 135°.View full abstractDownload PDF (2594K) -
Yukiaki Hara, Toshio Aida, Shin-ichi Kondo1968 Volume 32 Issue 1 Pages 73-77
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe iron-oxide pellets with 17∼30% porosity prepared from the pulverized Brazilian ore were reduced with hydrogen at 550°C and the weight chenges were continuously measured by a thermobalance, in order to evaluate the effects of the porosity on the reduction rate.
Obtained data were analyzed by a mixed-controlling mechanism of the intraparticle gaseous diffusion and the chemical reaction at the interface. Consequently, the intraparticle diffusivity De, the apparent chemical reaction constant kc and the time for complete reduction θ0 varied with the porocity ε0 as follows. In the porous pellet about 1 cm in diameter, De∝ε02, kc∝ε01.12 and θ0∝ε0−1.8.View full abstractDownload PDF (1312K) -
Yukiaki Hara, Masaru Tsuchiya, Shin-ichi Kondo1968 Volume 32 Issue 1 Pages 77-83
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBrazilian and Indian ores, high quality hematites, were ground spherically and then reduced with hydrogen at 500° and 550°C. The weight changes were measured by a thermobalance. Obtained data were analyzed by a mixed-controlling mechanism of the intraparticle gaseous diffusion and the chemical reaction at the interface.
In Brazilian ore, the crack developes into the network along grain-boundaries in the early stage of reduction and its width is larger than 1 μ. Therefore the intraparticle diffusivity is large and the reducibility is similar to that of the porous pellet. In Indian ore, the size of pore resulted by the reduction is several hundreds Å in radius, indicating that the intraparticle diffusion is akin to the Knudsen diffusion. The diffusing resistance is relatively large and the reducibility is inferior to that of Brazilian ore.View full abstractDownload PDF (2208K) -
Tohei Ototani, Yasuzi Kataura1968 Volume 32 Issue 1 Pages 84-88
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSEffects of sulphur, oxygen and silicon on the graphite precipitation of calcium graphite steel were investigated. Sulphur greatly hindered graphite precipitation from a γ solid solution. According to the additional amount from 0.03 to 0.18% of sulphur, primary cementite appeared not only in the matrix but also in the grain boundary. With increasing oxygen content above 0.008%, graphitization decreased and also primary cementite crystalized out preferentially from the γ solid solution. When the hypereutectoid steel was melted in vacuum, graphitization did not occur without a suitable silicon addition. Fundamental conditions on graphite precipitation by the calcium treatment were summarized in the following three points: (1) effect of deoxidization and desulphurization, (2) instabilization of cementite to precipitate from the γ solid solution, and (3) formation of crystal imperfections such as voids in the solidifying process. Effective acceleration of graphite precipitation due to silicon was finally considered.View full abstractDownload PDF (2390K) -
Tohei Ototani, Yasuzi Kataura1968 Volume 32 Issue 1 Pages 89-94
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSGraphitization and mechanical properties of calcium or silicon graphite steel containing 1.2∼1.5%C and 0.4∼1.7%Si were investigated. With increasing carbon and silicon contents, graphitization of these hypereutectoid steels increased, most remarkably in the range from A1 to the vicinity of Agr transformation. Graphitization of calcium treated graphite steel became greater than that of silicon treated one. Consequently the lower limit of silicon content for the graphitization of the calcium graphite steel may be decreased down to 0.6%. The mechanical properties of the heat treated graphite steel were seriously affected by the matrix structure, and it seemed that it was influenced indirectly by the amount of free graphite.View full abstractDownload PDF (2491K) -
Makoto Ohsawa, Yoshitoshi Hagiwara, Akira Nakagawa, Kazumasa Inoue, At ...1968 Volume 32 Issue 1 Pages 95-100
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis paper discribes the effect of aging temperature and time on the mechanical properties of 18%Ni-Maraging steel wires which have been drawn from a solution treated wire at original size 3.72 mm dia.to 2.5 mm dia. (54.8%,R.A; reduction of area in drawing), 2.0 mm dia. (71.2%, R.A) and finally to 0.7 mm (96.5%, R.A). Consideration is also given to the defference between as-drawn wires and aged wires (480°C×3 hr) at each draft size. The following is the summary of the results.
(1) Up to 75% reduction of area in drawing, there appear no appreciable effect of work hardening. Over 75% reduction of area in drawing, rapid work hardening of the wire is noted.
(2) The torsional and tensile strength of the wire after aging treatment increase with reduction of area in drawing.
(3) The elastic limit ratio (τ0.03⁄τB), the yield ratio (τ0.3⁄τB) in torsion increase with reduction of area in drawing. However, the elastic limit ratio (σ0.05⁄σB), the yield ration (σ0.2⁄σB) of tension are little affected by the reduction of area in drawing.
(4) Young’s modulus of both as-drawn and aged wires decreases as the reduction of area in drawing increase, while the shearing modulus is increased by higher reduction of area in drawing.
(5) The elongation and torsion value gradually decrease as the reduction of area in drawing increases. The value of reduction of area of the aged wire sharply decreases at 70% reduction of area in drawing.
(6) The maximum strength of the aged wire is shown at the temperature of 480°C(3 hr) regardless of the drawing history. Among them the 0.7 mm wire (96.5%,R.A) has the sharpest increase in strength.
(7) The time to reach the maximum strength is 2 hr for the 2.0 mm wire (71.2%, R.A) and the 2.5 mm wire (54.8%, R.A), while 3 hr is needed for the 0.7 mm wire drawn to 96.5% reduction of area in drawing.View full abstractDownload PDF (1720K) -
Hiroshi Konno, Katsuya Kudaka1968 Volume 32 Issue 1 Pages 101-102
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDownload PDF (377K)
- |<
- <
- 1
- >
- >|