Tetsu-to-Hagane

Japanese Economy in the Future

Yoshihiro INAYAMA

1981 Volume 67 Issue 2 Pages 225-229
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_225

JOURNAL FREE ACCESS

Download PDF (2617K)
On the Progress of Ladle Metallurgy

Yoshiharu IIDA

1981 Volume 67 Issue 2 Pages 230-244
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_230

JOURNAL FREE ACCESS

Download PDF (2935K)
Fatigue Crack Growth Property of Steel with Particular Reference to Threshold Stress Intensity Range, ΔK_th

Kohichi TANAKA

1981 Volume 67 Issue 2 Pages 245-261
Published: February 01, 1981
Released on J-STAGE: January 18, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_245

JOURNAL FREE ACCESS

Download PDF (3067K)
Horizontal Continuous Casting of Steel

Masaharu ITO

1981 Volume 67 Issue 2 Pages 262-268
Published: February 01, 1981
Released on J-STAGE: May 07, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_262

JOURNAL FREE ACCESS

Download PDF (7012K)
Present Status and Possibilities of High Pressure Utilization

Akira SAWAOKA

1981 Volume 67 Issue 2 Pages 269-274
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_269

JOURNAL FREE ACCESS

Download PDF (1155K)
Review of Magnetic Materials and Technology Forcast

Hideo KANEKO

1981 Volume 67 Issue 2 Pages 275-288
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_275

JOURNAL FREE ACCESS

Download PDF (2904K)
The Function and the Material of the Shadow-Mask for a Color Picture Tube

Kenichi FUKUZAWA, Akira TAKAI

1981 Volume 67 Issue 2 Pages 289-294
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_289

JOURNAL FREE ACCESS

Download PDF (4484K)
Estimation of Hardenability of Steels

Shogo KANAZAWA

1981 Volume 67 Issue 2 Pages 295-302
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_295

JOURNAL FREE ACCESS

Show abstractHide abstract

[in Japanese]

View full abstract

Download PDF (1343K)
Melting Rate of Iron Oxide Pellets into Iron Melt

Akira SATO, Ryuichi NAKAGAWA, Shiro YOSHIMATSU, Akira FUKUZAWA, Tsuyos ...

1981 Volume 67 Issue 2 Pages 303-312
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_303

JOURNAL FREE ACCESS

Show abstractHide abstract

Iron oxide pellets being resistant to crushing into pieces on adding onto the iron melt were made from iron oxide powder by pressing and sintering. The melting rate of pellets into iron melt and the reducing rate of pellets by carbon in iron melt were obtained by measuring CO gas evolved. The effects of the kind of iron oxide, oxide additives in pellets, temperature and carbon content of iron melt on the melting rate, and the rate of reduction of solid iron oxides by carbon in iron melt were investigated. The following results were obtained:
(1) The result using heated pellets showed that the heat transfer was not the rate-determining step. The estimated diffusion layer of carbon in iron melt showed that the carbon transfer could be the rate-determining step. Both the carbon transfer and the chemical reaction were estimated to control the melting and reducing of iron oxide.
(2) The relation between the total reduction and the time was linear from about 20% to about 70% of the reduction, where solid iron oxides were reduced by carbon dissolved in iron melt.
(3) The apparent activation energies of melting of pellets into the carbon saturated iron melt were 35 for Fe₂O₃, 18 and 41 for Fe₃O₄ above and below 1470°C, and further 44 and 79 kcal/mol for FeO above and below 1470°C, respectively.
(4) The melting rates of Fe₂O₃, Fe₃O₄, and FeO pellets into the iron melt at 1570°C were proportional to the 0.57, 0.45, and 0.42 power of the carbon content in iron melt (wt %), respectively. The minimum volume cf CO gas evelved was obtained at about 2% C.

View full abstract

Download PDF (9346K)
Deformation and Failure Behavior of Refractories for Blast Furnace at Elevated Temperature

Manabu MIYAMOTO, Toshio ONOYE, Kiichi NARITA

1981 Volume 67 Issue 2 Pages 313-322
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_313

JOURNAL FREE ACCESS

Show abstractHide abstract

The complete stress-strain curve for brittle materials cannot be obtained with conventional testing machines because of their low stiffness and difficulties in strain-control. In this paper, the deformation and failure behavior of refractories for blast furnace under strain-controlled uniaxial compression with a stiff testing machine is discussed.
It is found that the refractories retain some strength and have still appreciable elasticity even after the maximum stress is reached. Fireclay brick shows anisotropy with regard to the stress-strain curve. It has a large deformability and superior resistance to the failure by thermal stress in parallel to the direction of press forming. Carbon brick fractures with a small deformation after the maximum stress. At the temperature above 800°C, fireclay brick exhibits visco-elastic behavior, which is substantially explained by the Burgers model.

View full abstract

Download PDF (7133K)
Refining Process of Molten Iron by Sodium Carbonate

Katsukiyo MARUKAWA, Yoshiyasu SHIROTA, Syozi ANEZAKI, Hiroaki HIRAHARA

1981 Volume 67 Issue 2 Pages 323-332
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_323

JOURNAL FREE ACCESS

Show abstractHide abstract

As far as we use a blast furnace to produce hot metal, it is most important to control dephosphorization for the improvement of the present steel making process. In view of this, many refining processes to control dephosphorization economically have been studied.
We investigated the refining process of molten iron by using sodium carbonate, mainly for dephosphorization, and obtained the following results,
(i) When the sodium oxide type slag is used, the simultaneous dephosphorization and desulfurization occur, because dephosphorization proceeds in spite of its very low total iron content in comparison with the calcium oxide type slag.
(ii) The degree of dephosphorization is affected by the content of carbon and silicon in molten iron as well as temperature.
(iii) The prospect for a new steel making process based on the treatment by sodium carbonate depends upon the establishment of a technique to control desiliconization of hot metal, the simultaneous dephosphorization and desulfurization by sodium carbonate, and the development of a sodium carbonate recovery process from the slag.

View full abstract

Download PDF (1464K)
Theoretical Analysis of Electromagnetically Driven Flows in Continuous Casting and Model Experiment

Shigeo ASAI, Nobuyuki NISHIO, Iwao MUCHI

1981 Volume 67 Issue 2 Pages 333-342
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_333

JOURNAL FREE ACCESS

Show abstractHide abstract

In order to decrease center segregation together with center porosity, electromagnetic stirring has been applied to continuous casting of billets, blooms and slabs. As well known, however, the violent agitation in the pool is powerful to prevent center segregation, but promotes the formation of white band.
To tackle this problem, the laminar and turbulent electromagnetically driven flows in the pool are theoretically analyzed. Especially focusing on the effect of the electromagnetically driven reverse-turn flows on the structure, the solidification experiments are conducted by use of the Sn-10% Pb alloy.
Theoretical equation of the maximum velocity appearing at every half period for the reverse-turn flow is given as follows:
υ_max=κ₂(σω/μ)^1/4·√χ₀/ρ·B (1-e^-1/2fθ), θ=κ₃√χ₀ρ/{σω/μ^1/4B}
where, B: magnetic current density, κ₂, κ₃ : constants, χ₀ : half thickness of slab, μ: magnetic permeability, ρ: density, σ: electric conductivity, f: cycle of reverse-turn flow.

View full abstract

Download PDF (7173K)
Aging Properties of High Strength Cold Rolled Steels with Dual Phase Microstructure

Kiwami KURIHARA, Kenji ARAKI, Kazuhide NAKAOKA

1981 Volume 67 Issue 2 Pages 343-352
Published: February 01, 1981
Released on J-STAGE: January 18, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_343

JOURNAL FREE ACCESS

Show abstractHide abstract

Aging propcrties of cold rolled high strength steels produced with WQ CAL process (continuous annealing line equipped with a water quenching device) were studied with regard to the factors characterizing these steels such as the second phase (martensite) and a considerable amount of solute C, N atoms in ferrite phase. The results are as follows;
1. The second phase suppresses the recovery of yield point elongation (YP-El). The extent of this suppression depends on the volume fraction and the hardness of the second phase.
2. Because of this suppression, no recovery of YP-El is observed until the aging advances to such high degree that the activation energy of aging, determined from the increase in yield stress (ΔYS) or YP-El, is 26 to 30 kcal/mol.
3. Following consecutive cycles of temper-rolling and subsequent aging (at 170°C for 20 min), discontinuous yielding repeats appearing and disappearing. The solutes C and N decrease distinctively during the first aging treatment and no appreciable change is detected in subsequent treatments.
On the basis of these results, the reason and the condition for the remarkable feature of these steels, as characterized by the large ΔYS after the BH-treatment (an aging treatment at 170°C for 20 min) and no YP-El after the room temperature aging (simulated by storage at 38°C for 30 days), are discussed. Discussion on the difference in the influence of carbon and nitrogen and the related aging mechanism is also made. Finally overall picture of the aging behaviour of those dual phase steels is proposed.

View full abstract

Download PDF (1723K)
Effects of Cold Work, Heat Treatment and Volume Fraction of Ferrite on Stress Corrosion Cracking Behavior of (α-γ) Duplex Stainless Steel

Kikuo TAKIZAWA, Yasuhiko SHIMIZU, Eisaku YONEDA, Imao TAMURA

1981 Volume 67 Issue 2 Pages 353-361
Published: February 01, 1981
Released on J-STAGE: January 18, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_353

JOURNAL FREE ACCESS

Show abstractHide abstract

The effects of cold rolling, heat treatment and volume fraction of ferrite on stress corrosion cracking (SCC) behavior of duplex stainless steel have been studied with means of U-bend method in boiling 42% MgCl₂ solution. The main results obtained are as follows:
(1) SCC susceptibitity of the solution treated material is small at about 50% α, but it has a tendency to be increased with either way of increase or decrease of α content from about 50% α. Solution treatment temperature resulting in abrupt increase of SCC susceptibility shifts to higher temperature with the decrease of α content.
(2) SCC susceptibility is increased by grain growth of α and γ that occurred with extension of holding time at solution temperature, and otherwise, by cold work in the case of the materials having much volume fraction of α.
(3) On aging at 475°C, the hardness is increased by spinodal decomposition of α. The crack resistance increases remarkably with the progress of aging in the case of materials having much α, and corresponds to age hardening behavior.
(4) In the case of heating at 700°C, the SCC behavior of aged materials has not been made clear by U-bend method because of σ embrittlement.

View full abstract

Download PDF (14122K)
The Effect of Alloying Elements on the Static Recrystallization of Mild Steels in the Austenite Range

Yasuhiro MAEHARA, Tatsuro KUNITAKE, Nobukatsu FUJINO

1981 Volume 67 Issue 2 Pages 362-371
Published: February 01, 1981
Released on J-STAGE: January 19, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_362

JOURNAL FREE ACCESS

Show abstractHide abstract

The effects of addition of various alloying elements to a steel having base composition (0.1 C-0.3 Si-1.0 Mn) on the static recrystallization in the austenite range have been studied by a high temperature double tension method.
It was observed that recrystallized grains nucleated at the grain boundaries and that recrystallization time increased linearly with increasing initial grain size. At 900°C, recrystallization after strained to 0.2 by the first tension was retarded by the addition of Si (_??_1.0), Mn (_??_2.5), Ni (_??_1.0), Cr(_??_1.0), Cu (_??_0.3), Nb (_??_0.04), V (_??_0.1) and Mo (_??_0.4). Among them the retardation effect of Nb was remarkable, and this was explained by precipitation of NbC. On the other hand, the role of other elements in the retardation was ascribed to substitutional solid solution effect. In the Nb added steel, the degree of retardation was found to be significantly influenced by the heating history before a double tension test. This can be explained by the difference in the dispersion of NbC precipitates in addition to the initial grain size. The contribution of individual effect of grain size or precipitation on recrystallization was separated in an analytical way. Recrystallization rate increased with increasing C content (0.0020.07), but this was interpretated as due to the indirect effect of initial grain refinement by carbon.

View full abstract

Download PDF (4024K)
Behavior of Line Pipe Steels under Cathodic Protection

Komei KASAHARA, Tsuyoshi ISOWAKI

1981 Volume 67 Issue 2 Pages 372-381
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_372

JOURNAL FREE ACCESS

Show abstractHide abstract

Hydrogen stress cracking (HSC) susceptibility of various line pipe steels was evaluated by means of a slow strain rate technique (SSRT) as well as a conventional static load technique (SLT). Effects of strain rate, temperature, pH, applied potential, applied cathodic current density and hardness on the HSC susceptibility were made clear. The results obtained are summarized as follows:
(1) The results obtained by SSRT were quite analogous to, but more quantitative than those obtained by SLT. SSRT was proved to be quite a pertinent technique to evaluate the HSC susceptibility of line pipe steels being classified into go or no-go categories.
(2) The HSC susceptibility depended on the strain rate with highest in the strain rate region of 10^-6 and 10^-7 sec^-1 and decrease in the higher strain rate region.
(3) The HSC susceptibility depended on the applied potential increasing with cathodic polarization.
(4) The HSC susceptibility increased markedly with increasing current density of up to 2 mA/cm², but was almost constant and highest in the region over 2 mA/cm².
(5) The HSC susceptibility was not affected by pH in the pH range between 4 and 12, while increased markedly with decreasing pH values of less than 4.
(6) Hardness was a vital factor ihfluencing the HSC susceptibility of line pipe steels. The critical value, below which the steel would be free from HSC, for each line pipe steel was Hv=260 for API Spec 5LX-X65CR and QT, 265 for X60CR, 220 for X42 and 240 for JIS STPY-41.

View full abstract

Download PDF (8127K)
Temperature Dependence of J_IC Fracture Toughness Values in the Structural Steels and Evaluation of the Testing Method

Haruhiko FUJITA, Manabu TANAKA, Osamu KAMIYA

1981 Volume 67 Issue 2 Pages 382-390
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_382

JOURNAL FREE ACCESS

Show abstractHide abstract

The fracture toughness of four kinds of structural steels with relatively high elongation at room temperature has been evaluated by the electrical potential method and by other methods between at room and liquid nitrogen temperature. The results obtained are summarized as follows:
(1) At room temperature, (J_IC) _E value by the electrical potential method was very close to ( J_IC) _R value by the R curve method. ( J_IC) _S value by the SZW method was 15% higher than ( J_IC) _E value.
(2) At room temperature, the crack initiation detected by the inflection of the electrical potential corresponded to the stage where the formation of type II dimple and the internal necking occurred. Before the crack initiation, voids were already formed in front of the stretched zone.
(3) J_IC value increased with decreasing the testing temperature because of an increase in the yield strength, while it decreased drastically when cleavage fracture occurred at the precrack tip.
(4) J_IC value, CTOD (δ) and K_IC were related with each other as follows:
J_IC=1.79_δy·δ (for ductile fracture)
K_IC=0.81√J_IC·E (for brittle fracture)

View full abstract

Download PDF (6974K)
The Embrittlement of Blackheart Malleable Iron

Nobuhisa TSUTSUMI, Tsutomu TAKEUCHI

1981 Volume 67 Issue 2 Pages 391-398
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_391

JOURNAL FREE ACCESS

Show abstractHide abstract

An investigation has been made of the effect of cooling rate from both 450 and 650°C and also the effect of treatments consisting of various combination of heating rate, holding temperature and cooling rate on the shift of transition temperature of blackheart malleable iron by impact test. IMA analysis has been also carried out on the fracture surface of specimens cooled from 450°C under the various cooling conditions.
The results obtained are as follows:
(1) Holding at 650°C or slow cooling from 450°C shifts the transition temperature to lower temperatures.
(2) Q uenching from 450°C increases the tendency of embrittlement.
(3) Any heat treatment have no effect no the transition temperature when cooled from 650°C after 0.5 h. holding.
(4) The influence of cooling fate from 650°C to room temperature on the embrittlement of blackheart malleable iron is almost the same as that in the temperature range from 650°C to 450°C.
(5) IMA analysis on the fracture surface of blackheart malleable iron cooled from 450°C with various cooling rate shows that the larger the cooling rate is, the higher the phosphorus concentration on the fracture surface becomes.

View full abstract

Download PDF (1293K)
Development and Utilization of Dual Phase Steels in the United States of America

Takashi FURUKAWA

1981 Volume 67 Issue 2 Pages 399-405
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_399

JOURNAL FREE ACCESS

Download PDF (1421K)
A History of Ironmaking from the Aspect of Burden Dressing Technology

Michiharu HATANO

1981 Volume 67 Issue 2 Pages 406-408
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_406

JOURNAL FREE ACCESS

Download PDF (697K)
[title in Japanese]

[in Japanese], [in Japanese]

1981 Volume 67 Issue 2 Pages 408-408,410
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_408

JOURNAL FREE ACCESS

Download PDF (694K)
[title in Japanese]

[in Japanese], [in Japanese]

1981 Volume 67 Issue 2 Pages 415-419
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_415

JOURNAL FREE ACCESS

Download PDF (769K)
[title in Japanese]

[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...

1981 Volume 67 Issue 2 Pages 420-425
Published: February 01, 1981
Released on J-STAGE: June 19, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.67.2_420

JOURNAL FREE ACCESS

Download PDF (1333K)

Register with J-STAGE for free!