Tetsu-to-Hagane

Investigations in Innovative Steelmaking Technologies in Japan

Focused to the Metallurgical Phenomena Stimulating the Developments of More High-purity Refining of Steel and Continuation of Steelmaking Processes

Kiminari KAWAKAMI

1986 Volume 72 Issue 16 Pages 2153-2168
Published: December 01, 1986
Released on J-STAGE: February 16, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2153

JOURNAL FREE ACCESS

Show abstractHide abstract

[in Japanese]

View full abstract

Download PDF (4553K)
The Present Status of Chemical Analysis for Microamounts of Impurities in Iron and Steel

Sen-ichi HARIMAYA

1986 Volume 72 Issue 16 Pages 2169-2175
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2169

JOURNAL FREE ACCESS

Download PDF (1354K)
Fundamental Concept of Metallic Solidification and Its Application

Tadayoshi TAKAHASHI

1986 Volume 72 Issue 16 Pages 2176-2186
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2176

JOURNAL FREE ACCESS

Download PDF (11646K)
Dynamic Fracture Toughness and Its Measurement

Yoshifumi NAKANO

1986 Volume 72 Issue 16 Pages 2187-2193
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2187

JOURNAL FREE ACCESS

Show abstractHide abstract

[in Japanese]

View full abstract

Download PDF (2345K)
Flow Characteristics of Gas and Fine Particles in a Two-dimensional Space of Packed Bed

Hideyuki Yamaoka

1986 Volume 72 Issue 16 Pages 2194-2201
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2194

JOURNAL FREE ACCESS

Show abstractHide abstract

In order to evaluate the effect of powder on the blast furnace operation, the 2-dimensional behavior of gas and powder in packed bed with a tuyere on it's wall side were studied by a mathematical simulation model as well as a cold model experiment. Results obtained are as follows;
1) When the gas velocity along the wall side is decreased, powder tends to accumulate near the wall above tuyere resulting in the increase in pressure drop of gas and the decrease in gas flow rate near the wall.
2) The deterioration of gas permeability accompanied by the decrease in wall temperature at the lower part during the reduced production operation of blast furnace can be attributed to the accumulation of fine coke near the wall.

View full abstract

Download PDF (2720K)
Simulation of Burdens in Blast Furnace Using On-line Mathematical Simulator

Kuniyoshi ISHII, Oshiaki KASHIWAYA, Hideyoshi YAMAGUTI, Shin-ichi KOND ...

1986 Volume 72 Issue 16 Pages 2202-2209
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2202

JOURNAL FREE ACCESS

Show abstractHide abstract

A hybrid blast furnace simulator has been developed on the basis of mathematical model and experiments by combining differential fixed-bed reactor and micro computers. Assuming that the burden and gas phase moved counter-currently in the blast furnace, the experimental conditions were calculated in real time by putting in situ measured rates of reduction and solution loss to the differential equations of mass and heat balance, and the new experimental conditions were set at next stage. The simulation was performed by repeating the sequence.
(1) If simulation conditions were set up so as to fit the burdens, the simulation successfully proceeded and the longitudinal distribution of process variables in B.F. could be expected precisely according to the reactivity of burdens.
(2) When the operations with pellet and sinter were simulated, thermal reserve zone was longer and smelting reduction began at lower temperatures for the former than for the latter.
(3) With lower coke rate, reduction hardly proceeded and burden was heated up during short descending. On the other hand, with higher coke rate, although reduction proceeded fast, burdens remained at low temperatures.

View full abstract

Download PDF (1607K)
Solubility and Dissolution Rate of Water Vapor in Liquid CaO-Si0₂-Mg0 and CaO-SiO₂-TiO₂ Slags

Shiro BAN-YA, Yasutaka IGUCHI, Seiji YAMAMOTO

1986 Volume 72 Issue 16 Pages 2210-2217
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2210

JOURNAL FREE ACCESS

Show abstractHide abstract

The solubility of water vapor and the rate of water vapor dissolution in liquid CaO-SiO₂-MgO and CaO-SiO₂-TiO₂ slags have been measured by a sampling method.
The solubilities of water in slags at 1 450°C were shown with water-vapor capacity, defined by log K'=log {(%H₂O)_s√P_H₂O}.
The water vapor dissolution in these liquid slags would be controlled by diffusion of H₂O in the bulk slag the same as in the CaO-SiO₂-Al₂O₃ system. The apparent diffusion coefficient of water vapor, DH₂O, was evaluated and the effects of slag composition, such as basicity, MgO or TiO₂ content and temperature on DH₂O were discussed.

View full abstract

Download PDF (1367K)
Process Development and Stability Analysis of Horizontal Electromagnetic Casting Method

Shigeo ASAI, Toshiyuki KOZUKA, Iwao MUCHI

1986 Volume 72 Issue 16 Pages 2218-2224
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2218

JOURNAL FREE ACCESS

Show abstractHide abstract

A new process of horizontal electromagnetic casting (HEMC) described as non-mold casting is proposed in which the molten metal is levitated by imposing direct current and direct magnetic field. This process may be favorably applied to the casting of heavy metals, since strong electromagnetic force can be induced at the expense of a small quantity of electric energy. On the other hand, in case of the ordinary process of vertical electromagnetic casting (VEMC), a large amount of electric energy and cost of equipment are indispensable for casting a heavy metal. By using this process, the alloy of 56%Bi-40%Sn-4%Zn (M.P.=403 K, ρ=8.7×10³ kg/m³) was cast to simulate the casting of molten steel, and the surface defects arising by the metal-mold contact could be eliminated.
Furthermore, the stability analysis is developed to confirm the applicability of this process and to determine the stable operating conditions.

View full abstract

Download PDF (4076K)
Prevention of Inner Cracks by the Optimum Roller Arrangements in a High Speed Continuous Slab Caster

Kunihiko ONISHI, Kunio NAGAI, Toshie HASHIMOTO

1986 Volume 72 Issue 16 Pages 2225-2232
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2225

JOURNAL FREE ACCESS

Show abstractHide abstract

Concerning a high speed continuous slab caster, strains in a slab were analyzed and a state of loads act on rollers was discussed. From this analysis, the followings were elucidated:
1) The maximum strain in a slab caused by bulging is the component in the casting direction on a inner surface of a shell in a broad side of a slab just under a roller.
2) The allowable roller pitch to prevent internal cracks of a slab caused by bulging becomes much smaller as a temperature of a slab becomes higher. But the influence of a casting speed on the allowable roller pitch is small.
3) Straightening strains in a slab advance not along a designed radius of a machine but along a curvature defined geometrically by a roller arrangement, and the variation of strains of a slab is not linear in a roller pitch and in some cases strain rate becomes very large.
4) For high speed casting, multi-straightening is necessary to prevent internal cracks of a slab caused by straightening strains.
Further, using the results of this investigation, a method of the decision of proper arrangements and constructions of rollers to prevent internal cracks of a slab was systematized.

View full abstract

Download PDF (1263K)
Operation High Speed Slab Caster for Hot Direct Rolling

Takayuki KOYANO, Yusuke SHIRATANI, Shigetaka UCHIDA, Tsutomu WADA, Tos ...

1986 Volume 72 Issue 16 Pages 2233-2239
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2233

JOURNAL FREE ACCESS

Show abstractHide abstract

The slab caster No.5 was put into operation in September, 1984 at NKK Fukuyama Works, which was directly connected with the hot strip mill No.2 for the purpose of Hot Direct Rolling Process (HDR).
To realize the HDR this caster is provided with various automatic facilities and with several characteristics on operation such as mentioned below.
(1) For high speed casting (over 2.0 m/min); low viscosity mold powder (lithium being added), nonsinusoidal oscillation, and mold copper plate, etc.
(2) For high temperature slab discharging; heat insulating apparatus, secondary cooling with width control system, and slab edge heater.
(3) For improvement of surface and inner quality of slab; accurate mold level control, optimum design of immersion nozzle, air mist cooling, etc.
By these newly developed techniques the monthly production by the HDR process was increased up to 100 thousand tons of steel. This report describes the new facilities and the operation technologies developed for this HDR process.

View full abstract

Download PDF (968K)
Characteristics of Rapidly Solidified Cast Iron and High Carbon Steel

Chisato YOSHIDA, Kazuyuki TANIGUCHI, Tomokazu NAKAGAWA, Masatoshi SUDO ...

1986 Volume 72 Issue 16 Pages 2240-2247
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2240

JOURNAL FREE ACCESS

Show abstractHide abstract

After the energy crisis the steel industry is required to minimize its energy consumption. Direct connection with a hot rolling process in continuous casting is one of the solutions for this problem. Furthermore along with the developments of the continuous casting process, new casting processes are presently under development with the objective of eliminating most parts of the rolling and heating processes.
As the solidification rate of the rapidly solidified plate in the new casting processes is 10⁰10³°C/s, the properties of the cast plate are expected to be improved. As the first step in our experiment, the properties of cast iron and high carbon steel were investigated.
Thin sheets of cast iron were made by the twin roll test caster and cold rolling. Cold rolling was attainable due to the fine spheroidal graphite structure formed by the rapid solidification and the following annealing.
Furthermore, rapid solidification of high carbon steel was investigated by using the water-cooled chill block apparatus, which was supposed to function similarly to a caterpillar type caster. The rapid solidification promoted less macrosegregation and finer MnS inclusions.
It is well known that in the high carbon steel, the heat treatment is necessary for spheroidizing the cementite structure. It was proved, however, by the rapid cooling at eutectoid temperature, the spheroidal cementite structure was obtained in a relatively shortened annealing time.

View full abstract

Download PDF (10092K)
Development of Camber Control Technique in Plate Rolling

Kazuo OHMORI, Masatoshi INOUE, Takanori MIYAKE, Yuji TANAKA, Katsumi N ...

1986 Volume 72 Issue 16 Pages 2248-2255
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2248

JOURNAL FREE ACCESS

Show abstractHide abstract

In plate rolling, camber is a cause of not only yield loss and poor grade, but also an extra process at the shearing line, calling for an establishment of a camber control technique.
This report presents the analysis of camber mechanism, the development of camber-meter and the effect of camber control in the Mizushima plate mill. The results obtained are as follows;
1) Relation between camber and wedge in plate rolling and factors affecting wedge mechanism were clarified, and high-accuracy models applicable to camber control were developed.
2) Plate camber can be measured accurately regardless of sideslipping or turning of a plate during rolling by a developed camber measuring system (camber meter).
3) A dynamic camber control technique using camber meter and camber control model was developed. Camber is reduced noticeably in various plate length by applying this control technique.

View full abstract

Download PDF (1110K)
Effects of Pre-hipping and Other Extrusion Conditions in Gatorizing Process

Shizuo NAKAZAWA, Isao TOMIZUKA, Yutaka KOIZUMI, Hiroshi HARADA, Michio ...

1986 Volume 72 Issue 16 Pages 2256-2262
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2256

JOURNAL FREE ACCESS

Show abstractHide abstract

Effects of some processing factors in Gatorizing process were investigated for a high-W and high-Ta Ni-base superalloy. Optimum extrusion temperature to obtain extrudents suitable for superplastic forging laid near but below 1 200°C, although superplastic deformation was materialized in a temperature range of 1 100 through 1 200°C. Hipping preceding extrusion caused lower superplasticity and narrower temperature range in which superplastically forgiable extrudents were available, while it improved ultimate tensile strength at 760°C and elongation at rupture thereby. Decrease in extrusion ratio caused decrease in pressure required for extrusion, but it casued decrease in superplasticity as well as deteriration of tensile strength at 760°C.

View full abstract

Download PDF (5800K)
Effects of the Conditions of Direct Hot Rolling after Continuous Casting upon the Mechanical Properties of Hot Rolled C-Mn-Nb Steel Sheets

Yoskio HASHIMOTO

1986 Volume 72 Issue 16 Pages 2263-2270
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2263

JOURNAL FREE ACCESS

Show abstractHide abstract

A study has been made of the effects of the conditions of direct hot rolling after continuous casting on the mechanical properties of hot rolled C-Mn-Nb steel sheets.
The following results are obtained.
(1) Austenite (γ) grain size after casting is very large compared with that after reheating at 1 250°C for 1 h. Ferrite grain sizes after hot rolling are almost equal in both processes. This is probably because y grain boundaries before hot rolling do not contribute to the ferrite refinement because of their very low densities.
(2) Tensile test results of steel sheets produced by both processes are almost the same if niobium is almost completely soluted before hot rolling.
(3). In case, total hot rolling reduction after casting is higher than 40%, total elongation becomes very large.
(4) Under the experimental condition of total hot-rolling reduction being 88%, the strengthening effect of niobium is saturated when niobium content is more than about.0.035%.
(5) The effects of the cooling rate in solidification (about 18 and 235°C/min at 1 500-1 300°C) and the heat history difference in the slab width on tensile properties are small in this direct hot rolling simulation test.

View full abstract

Download PDF (8763K)
Prevention of Hydrogen Induced Disbonding at the Interface between Cr-Mo Steel and Stainless Steel Overlay Weldment

Katsukuni HASHIMOTO, Yasuo OTOGURO, Toshiaki SAITO, Hiroyuki KOIKE, Ka ...

1986 Volume 72 Issue 16 Pages 2271-2278
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2271

JOURNAL FREE ACCESS

Show abstractHide abstract

Countermeasures against hydrogen induced disbonding at the interface between 21/4 Cr-1 Mo steel and overlaid stainless steel weldment in reactor vessels which are operated under high hydrogen pressures at elevated temperatures were investigated from the viewpoint of base steel and overlaid stainless steel respectively.
It is known that the disbonding is caused by formation of carbide after post weld heat treatment and accumulation of hydrogen during cooling at shutdown at the interface. As for base steel, 21/4Cr-lMo steel plate with surface layer 2-3 mm thick of low carbon concentration could prevent the disbonding under ordinary operation condition for direct desulphurizer of heavy oil. The thickness of the low carbon layer could be decreased by decreasing the carbon concentration. It was considered that prevention of the disbonding was realized at carbon concentration less than 0.050.06% at the interface.
As for overlaid stainless steel, the effect of the amount of δ ferrite on the disbonding was investigation. It was found that more than 18% of δ ferrite after post weld heat treatment was required to prevent the disbonding. δ ferrite seemed to be effective because of decreasing hydrogen content at the interface by increasing mean diffusion rate of hydrogen in the overlaid stainless steel.

View full abstract

Download PDF (9618K)
Influence of Nitrogen Addition to Duplex Stainless Steels

Akihiko HOSHINO

1986 Volume 72 Issue 16 Pages 2279-2286
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2279

JOURNAL FREE ACCESS

Show abstractHide abstract

The influence of nitrogen on structure, notched toughness and pitting corrosion resistance of duplex stainless steels was investigated, and a discussion was focussed on the role of N and Mo to pitting corrosion resistance.
Pitting corrosion test by immersion method showed that the corrosion rate of duplex stainless steels decreased with increasing N content under the presence of Mo. If Mo is absent in the N-bearing steels, beneficial effect of N, which can improve the pitting corrosion resistance of austenite, was not observed.
Corrosion pits tended to initiate at α/γ interface in the specimens water-quenched, and it was considered that the α/γ interfacial strain was responsible to enhanced corrosion rate of N-free steels.
The presence of Mo in N-bearing steel was thought not only to suppress the intergranular precipitation of nitride during cooling, but also to retard the pitting growth by lowering the active dissolution rate of anodic ferrite phase.

View full abstract

Download PDF (8071K)
Development of Full Automatic Sample Preparation and Analysis System for Powdered Sample and Pig Iron

Takashi SUGMARA, Keizi SAITO, Akihiro GODA, Toshihiko HATA

1986 Volume 72 Issue 16 Pages 2287-2292
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2287

JOURNAL FREE ACCESS

Show abstractHide abstract

A modern analytical computer system has been established as a part of totalized steelmaking information system at the Mizushima works, Kawasaki Steel Corporation. The modernization of the analytical system aimed at automating and refreshing of analytical equipments and real time data processing.
New computer and electronic technologies and hierarchical structure of computer have realized the system which has centralized the management of information and distributed the control for analytical equipments.
Furthermore, this system has contributed to improve the reliability through improvement in analytical precision, and also contributed to a decrease in operator's labor, because this system was automated from sample preparation to calculation of analytical contents for powdered samples and pig iron.
The process control and the quality assurance have been strengthened by the completion of this system.

View full abstract

Download PDF (4020K)
Quantitative Analysis of Zn-Fe Alloy Galvanized Layer by Secondary Ion Mass Spectrometry

Kenichi TAKIMOTO, Kenichi SUZUKI, Koichi NISIZAKA, Takashi OHTSUBO

1986 Volume 72 Issue 16 Pages 2293-2300
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2293

JOURNAL FREE ACCESS

Show abstractHide abstract

A method was established for quantitative analysis of Zn-Fe alloy galvanized layer by using Secondary Ion Mass Spectrometry. O₂⁺, N₂⁺, Ar⁺and Cs⁺ were used as the primaries. The sputtering yield and the relative secondary ion yield were found to depend on the alloy composition. The relative secondary ion yield, f(C_x) can be shown as a function of the alloy composition and the ratio of f(C_zn) to f(C_Fe) was independent of the alloy composition. The sputtering yield, the normalized secondary ion intensity, and relative secondary ion yield were also independent of the primary ion current density.
The secondary ion intensity of Zn and Fe of the Zn-Fe alloy plating by using nitrogen, argon, and cesium as primary ions depended on the coexisting oxygen.
A linear calibration curve can be obtained between the intensity ratio of I_Zn/I_Fe and the ratio of C_Zn/C_FeIt was shown that it is possible to analyse quantitatively the double-layered Zn-Fe alloy plating of micro-sized areas.

View full abstract

Download PDF (4373K)
[title in Japanese]

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

1986 Volume 72 Issue 16 Pages 2305-2307
Published: December 01, 1986
Released on J-STAGE: February 15, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2305

JOURNAL FREE ACCESS

Download PDF (787K)
[title in Japanese]

[in Japanese]

1986 Volume 72 Issue 16 Pages 2308
Published: December 01, 1986
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.72.16_2308

JOURNAL FREE ACCESS

Download PDF (210K)

Register with J-STAGE for free!