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Volume 27, Issue 10
Displaying 1-10 of 10 articles from this issue
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Susumu Yoshida, Tomoyuki Takeuchi, Norio Nagata1963 Volume 27 Issue 10 Pages 461-466
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAn experimental apparatus which enables us to perform impact extrusion a constant ram speeds has been constructed and successfully applied for the study of extrusion of high-purity aluminium. In this apparatus, extrusion is performed by means of impact of a long steel bar thrown at high speeds (the possible maximum speed: 50 m/sec). The duration of extrusion process is about 0.8 millisecond. Experiments have been carried out at room temperature with ram speeds ranging from 0.5 to 12 m/sec and extrusion ratios from 4.4 to 25. The results obtained are as follows: (1) The extrusion resistance (Q) increases with increasing extrusion speed (v) at a constant extrusion ratio, and the relation between them is expressed by the following formula, Q=kvn, where, for each different extrusion ratio, n seems to give a slightly different value, which is approximately 0.05. (2) The experimental relation between the extrusion resistance (Q) and the extrusion ratio (γ) is roughly expressed as Q(kg⁄mm2)=(15+21 ln γ)v0.05 (m/sec), including the extrusion speed (v). (3) The thickness of the deformation zone in residual billets is determined by hardness measurement and metallographical observation and is shown to be constant in the range of this experiment.View full abstractDownload PDF (1514K) -
Toshio Sait\={o}1963 Volume 27 Issue 10 Pages 467-474
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to obtain the decisive reason for the magnetism of work-hardened Hadfield steel, various composition of practical manganese steels were examined by the magnetic colloidal method after cold working. In every cases, whenever austenitic manganese steel is work-hardened by impact at room temperature, by static tension at room temperature, or by impact at liquid nitrogen temperature, small amount of ferromagnetic product are formed at the traces of slip planes and at the grain boundaries. These ferromagnetic product are not formed at every slip planes and at every grain boundaries observed in etched surface, but formed at very partial portion.
In unstable austenitic composition steels, both grain boundaries and slip planes are observed very clear line in magnetic colloid patterns, but as increasing carbon or manganese content in steels, these magnetism are gradually diminished slip planes first, and next grain boundaries. Ferromagnetic product are entirely not formed at grain boundaries in Fe-Mn alloys. The magnetism at grain boundaries can be decreased or diminished by annealing prior cold working, but the magnetism at the traces of slip planes can not be wholly affected.
ε phase in manganese steels are considered the paramagnetic substance as same as γ phase, but has slightly stronger magnetism than γ phase at room temperature. Even ε phase coexists in γ phase considerably much ratio, magnetic colloid does not adhere at both phases. It is considered that ferromagnetic product at grain boundaries in work-hardened Hadfield steel are caused by the segregation of carbon at grain boundaries, which are accelerated by cold-working and grown up to the complex carbide. Otherwise, it is anticipated that small amount of very thin martensitic layer are present along the traces of slip planes.View full abstractDownload PDF (4887K) -
Emiko Sudo, Tsutomu Takahashi, Hiroyuki Inoue1963 Volume 27 Issue 10 Pages 475-481
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe purposes of these experiments are selection of internal standard element and suppressive effects of spectrochemical buffers for analysis of a low purity metallic silicon (99∼97%).
As to an internal standard spectral line, there are no suitable silicon spectral lines revealing optimum intensity in the measuring spectral region. So the authors selected strontium with consultation of the Ahrens’s and others.
The silicon oxide band spectrum and background emission make an analysis difficalt when metallic silicon powder is excited alone in the air. But an addition of graphite powder caused a repressing effect of background and a suppressive effect of selfabsorption of SrI2932Å spectral line. The suppressive action on graphite powder matrix was attributed to the formation of silicon carbide, strontium carbide and silicate strontium. This fact made clear by X-Ray diffractive analysis of residues after discharge. But the addition of potassium carbonate and sodium chloride interfered with the formation of carbide and silicate strontium. Germanium dioxide attributed to the enhancement of silicon spectral lines.
Consequentry, it was indicated that the impurity of the low purity metallic silicon could be analysed with good accuracy by addition of strontium carbonate 1/5 times and graphite powder 5 times the weight of sample.View full abstractDownload PDF (1674K) -
Shin’ichi Nagashima, Shozo Sekino, Hiroshi Kato1963 Volume 27 Issue 10 Pages 481-485
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe plastic strain ratio R of single crystals of low carbon steel has been determined by a method of tensile test. From consideration of the deformation due to slip, R-value can be described as R=tan2θ, where θ is the angle between the thickness direction and the projection of operative slip direction onto a plane which is perpendicular to the axis of specimen. R-value obtained from the tensile test and that calculated from the above equation showed a considerably good agreement. Calculation has also been made on the plastic strain ratio of some single crystal specimens, the surface of which is parallel to (100), (110), (111) and (112) planes, respectively.View full abstractDownload PDF (872K) -
Minoru Tanaka, Shigetomo Nunomura1963 Volume 27 Issue 10 Pages 486-490
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe object of this paper is to study the breaking behaviours of a structural steel for low temperature service in Charpy impact bending test using the perforated notched test pieces which were proposed by one of the authors.
The results obtained in this paper are summarized as follows:
(1) The perforated notched test piece is available for the differentiation between the crack initiation and propagation stages. The crack initiation energy can be estimated easily by using the both of the perforated notched test piece and the standard key hole test piece.
By this method, the relationship between the breaking energy and the breaking length in brittle fracture can be also determined. This relationship indicates a distinct difference between the test steel and the high tensile structural steel already tested.
(2) The impact tensile strength can be calculated from the maximum load of load-time curve which has been obtained at the breaking of perforated notched test piece in Charpy bending test. The calculated values of impact tensile strength are about 1.1∼1.4 times of the values of upper yield strength obtained by the high speed tension test under the stress rate 4×106 kg/mm2·sec which is equal to the stress rate of Charpy bending test.View full abstractDownload PDF (1249K) -
Makoto Endoh, Jirou Namekata1963 Volume 27 Issue 10 Pages 490-496
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of containing vanadium (0∼2.7%) on the properties of 17Mn-12Cr type nonmagnetic austenite steel investigated. The results obtained were as follows.
(1) Hardness, yieled strength after aging treatment increased with the vanadium content. In all the specimens different in vanadium content the highest strength after aging was obtained by aging at 700°C×7 hr.
(2) The highest strength of the 17Mn-12Cr type nonmagnetic austenite steels, containing vanadium(1.1∼2.7%), aged after solution treatment, are all about 120 kg/mm2 in yield strength (0.2%), and nearly 15% in elongation. Magnetic permeabilities of these steels in aged condition are in the vicinity of 1.002.
(3) The cause for hardening of these austenitic steels is the formation of particular vanadium carbide by the addition of vanadium which has a strong affinity for carbon and the remarkable precipitation of the vanadium carbide by aging for a short time after solution treatment.View full abstractDownload PDF (2336K) -
Zenji Nishiyama, Ken’ichi Shimizu, Shiro Morikawa1963 Volume 27 Issue 10 Pages 497-502
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTwo types of martensites (ε′ and α′) produced in a bulk commercial 304-type stainless steel have been examined by means of transmission electron microscopy and selected-area electron diffraction. The results are as follows: (1) When the specimens were subzero-cooled to liquid nitrogen temperature, either of ε′-and α′-martensites was not observed in furnace-cooled specimens but both of them were observed in water-quenched specimens. In the former case, however, these martensites could be observed with specimens deformed at room or liquid nitrogen temperature. The deformation always produced ε′-martensite prior to the formation of α′-martensite which were formed only in the region between two sheets of neibouring ε′-martensites. (2) The α′-martensite has the form of a plate and its habit plane is probably near {259}γ planes. (3) The α′-martensite plates have no fine twin faults but have dislocation lines. Some of these dislocations appeared to be parallel with one another, signifying that they were distributed on a certain slip plane.View full abstractDownload PDF (3251K) -
Noboru Kawakami, Akira Hayashi, Masazo Okamoto1963 Volume 27 Issue 10 Pages 503-506
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe influence of different sort of raw material chromium on properties of Nichrome for electric heating materials has been clarified, this paper being the first report. The alloys containing the different sort of chromium were melted in magnesia crucible by high frequency induction heating under air of 100 mmHg, deoxidized with Ni-C or Ni-Mg, and then cast in a copper mold. The chemical compositions and the plastic workability of these ingots were examined. The results obtained were as follows.
(1) The Ni-C alloy was found to be mixed easily into the melt due to its high density, and a vigorous boiling phenomenon was observed to occur immediately after its addition causing the reduction of the oxygen content of the melt to a marked degree. (2) All ingots prepared by such process were capable of being forged, rolled and drawn, and also they did not show any noticeable difference among them. There was no trouble for both hot and cold working of ingots obtained from the home-made electrolytic chromium. However, air-melted Nichrome showed somewhat deterioration in the plastic workability, the effect of raw materials of chromium being found a little. (3) For the addition of 0.1% carbon by the Ni-C alloy, a boiling occurred for 14∼27 minutes, and 0.021∼0.007%C was found to remain in those ingots. The degree of the deoxidation of the molten metal was estimated to be about 0.1% as oxygen. Besides the deoxidation of molten Nichrome, some crucible reaction appeared to proceed.View full abstractDownload PDF (1134K) -
Ken’ichi Shimizu, Tyuki Ko, Zenji Nishiyama1963 Volume 27 Issue 10 Pages 506-512
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe structure of the bainite in a 0.7% carbon steel has been studied by means of transmission electron microscopy and selected-area electron diffraction. The lower bainite consists of lens-shaped ferrite grains in which internal fine cementite precipitates are formed on one kind of planes (probably stacking faults planes). This habit of the cementites are different from those in the tempered martensite, and moreover in the ferrite there are hardly seen any traces of the twin faults as found in the martensite. On the other hand, the cementite in the upper bainite has the form of a plate situated by the side of the ferrite plate which contains many dislocation lines.
Electron diffraction patterns showed that both the upper and lower bainite have nearly the same orientation relationships between the ferrite and the cementite. That is,
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\ oindentwhere relationships (2) agree with[100]cem||[01\bar1]α within experimental error. Referring to these results and the habit of the precipitated cementite, the formation mechanism of the bainite is discussed in connection with the martensite transformation.View full abstractDownload PDF (2552K) -
Yûnoshin Imai, Masao Izumiyama, Kyo Sasaki1963 Volume 27 Issue 10 Pages 513-518
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe spontaneous martensitic transformations were investigated using the Fe-base alloy containing 17%Cr and 81%Ni. The isothermal martensitic transformations occurred during holding at above Msγ→α′ temperature and gave a T.T.T. diagram in which there is a nose at about −100° and −135°C, respectively. X-ray diffraction measurement showed that h.c.p.structure (ε) is formed at the upper nose. The driving force (ΔFγ→ε) of transformation in this alloy was 22 cal/mol. This value was derived from an assumption in which the transformation occurs owing to a very low stacking fault energy. Furthermore, from this assumption, it was suggested that γ→ε transformation occurs at above 7.2%Ni content. This suggestion agreed closely with practical data. The b.c.c. martensite (α′) grew during further holding within the temperature range of the upper nose. The habit plane of this α′ was (111)γ. On the other hand, the habit plane of the α′ formed isothermally within the temperature range of the lower nose and athermally at a temperature below Msγ→α′ was (225)γ.View full abstractDownload PDF (1023K)
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