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Technical Report No.49 (2006)

Shinagawa Technical Report
No.49 (2006)

CONTENTS

Preface

What I have in mind

Senior Managing Director M. TERAO

Special Theme

Studies of New Refractory Components

A. YAMAGUCHI

Abstract

Carbon-containing refractories have excellent characteristics, however, they also have a severe shortcoming, easy oxidation.

Additives such as metals and carbides have been developed as antioxidants used in these refractories.

We found that some additives not only prevent the carbon oxidation but also give refractories a self-repairing function by forming a surface protective layer, decreasing porosity, improving corrosion resistance and increasing hot-strength.

More effective additives will be developed with attention to this function in the future.

Those components are predicted to be in M(metal)-O-C-N system.

In this paper, the application possibilities of Al-Si-C, Al-B-C and Al-C-O system compounds are discussed.

The First Coke Oven Constructed in Japan Over a Quarter Century

T. NAGASAKA, M. NAKAO and K. ISHII

Abstract

After a quarter century in Japan, coke oven construction was accomplished at JFE Steel Corporation West Japan works-Fukuyama.

The following is a report on the construction of the coke oven.

Reports

Formation of ZrC in ZrO2-C Material and Its Effect on Molten Steel Penetration

W. LIN, S. UCHIDA, A. WATAZU, T. SONODA and A. YAMAGUCHI

Abstract

The reaction between molten steel and ZrO2-C under an argon atmosphere at 1560oC for 1 h was examined.

Molten steel penetrated into the side of the ZrO2-C crucible up to 2~3 mm depth and a ZrC coating layer was formed on the ZrO2 particles there.

The wettabilities of porous ZrO2 and porous ZrC by molten steel were measured.

Molten steel wet the ZrO2 poorly, but wet the ZrC well so that the molten steel drop completely penetrated into the ZrC substrate.

These results indicate that the ZrC coating layer caused molten steel penetration into the ZrO2-C due to the good wettability between molten steel and ZrC.

Thermodynamically, ZrC is formed under the condition of the CO partial pressure being less-than or equal to 0.35 atm (at 1560oC) due to the reaction between ZrO2 and carbon.

So, the characteristics of ZrO2-C should be improved by preventing ZrC formation.

Technical Information on Products

Silica Bricks of Sinosteel Luoyang Refractory Co., Ltd.

Y. LI, H. WANG, T.KATOH and S. TANIGUCHI

Abstract

Shinagawa Refractories Co., Ltd. transferred all silica brick and insulating silica brick technology to Sinosteel Luoyang Refractory Co., Ltd. in 1991 and made an exclusive sales agreement for those bricks in the Japanese market.

Shinagawa has conducted the manufacturing instruction and delivery control and has successfully supplied more than 22,000 tons of silica bricks so far to various furnaces including hot blast stove, coke oven, glass tank furnace and so forth.

The silica bricks of Sinosteel Luoyang Refractory will be introduced in this report.

Precast Block for Coke Oven Door

M. KATAOKA and K. MORI

Abstract

There is a problem with precast blocks for the coke oven door of shortened refractory life because of carbon adhesion and crack expansion.

To overcome this problem, we examined the block structure and the burning process and the developed glaze coated blocks with anchors.

Application of Blocks to the Blast Furnace Trough

H.SHIKAMA , M.KITAMURA and S.TANIGAWA

Abstract

Castable refractories have been generally used for the blast furnace trough, but shaped refractories like fired bricks are not often used.

As the result of applying bricks and precast brocks to tilting spouts, iron troughs and slag runners, it had a marked effect on durability improvement.

Tap Hole Sleeve for BOF

M. NAKAMURA, Y. KAWATA, M.SUTOH and H. KUNII

Abstract

An improvement on BOF tap hole sleeve is required for many steel makers in order to avoid decreasing BOF productivity.

The newly developed low carbon MgO-C bricks for the BOF tap hole sleeve are appreciated by many customers in the world because of the performance stability with long life and less spalling damage.

In this report, we describe the features and actual results of our typical products.

Technology for Recycling Unshaped Refractories

Y.TAKAKURA, H.SASAKI and M. NANBA

Abstract

Recycling used refractories is one of the key technologies for improving the global ecology.

Unshaped refractories are widely used in steel making furnaces, but there are some problems in recycling unshaped refractories.

This paper introduces some examples of recycling technology for unshaped refractories.

Automatic Face Pressure Loading Slide Gate Valve Equipment

K. MITSUI, M.OSADA and H.MORII

Abstract

Shinagawa has developed new generation of slide gate valve equipment called "SST" that reduces both the time necessary to exchange the plates and the number of component parts to lower costs.

Face pressure loading and load release of the newly developed SV equipment are very simple.

The SST type slide valve equipment is composed of about half the number of parts used in ordinary equipment.

High Performance Slide Valve Gate Plate

T. SAEKI, N. IMAI and K. MORIWAKI

Abstract

Sliding surface damage of the SV plate severely affects its durability.

The main cause of sliding surface damage is considered to be the abrasion or peeling of the decabonized layer which is formed by dissolution of carbon in molten steel.

In this report, a new plate material with low carbon content which has both high abrasion resistance and high spalling resistance was described.

The newly developed SV plate material was used in an actual ladle and sliding surface damage was suppressed.

Mogul Lined Submerged Entry Nozzle

M. NAKAMURA, S. INOUE, and T. HORIUCHI

Abstract

The shape of submerged entry nozzles (SENs) has a great influence on steel quality and stable casting conditions in the continuous casting of steel

In order to increase casting velocity and improve steel quality, it is important to select the optimal SEN shape corresponding to the casting conditions.

Shinagawa discovered that the biased flow caused by slide gate throttling etc. can be eliminated by placing projections on the lining of the bore of the SEN.

We developed the annular step SEN in 1992, which has come to be widely used at many casters.

And, we developed the mogul SEN which is lined with many spherical convex projections on the bore in 2002 as a measure to meet increasingly complex needs.

The great effect of the mogul SEN has been confirmed in many continuous casting machines.

Application of the mogul SEN is increasing year by year.

The Latest Mold Powder Trends

T. OMOTO

Abstract

In recent years, casting conditions are severe, and so the requirements for mold powder are also very strict and important.

Additionally, casting speed is being increased to above 2.5m/min, called 3rd generation, so new mold powder products are required.

We developed some new unique mold powders with allow both stable higher casting speed operation and increased of steel quality Current trends, topics and development of new mold powder technology will be described in this paper.

New Mold Powder Product "REVIX" for Middle Carbon Steel Grade

T. OMOTO, H. OGATA and J. ITOH

Abstract

The main middle carbon steel defects are longitudinal cracks and transverse cracks on the steel strand surface and these defects prevented from the casting speed increase.

We have developed new mold powder "REVIX" and it contributes to increasing steel quality and productivity.

The main characteristics and effects of REVIX are described in this report.

Mini-Clean Shot (CLS) Equipment

Y. SASAI and J. OKUHARA

Abstract

Clean Shot (CLS) is widely used in mainly the iron and steel industry.

We have applied newly developed easily transportable Mini-Clean Shot (CLS) equipment to incinerator repair.

Mini-CLS equipment can be set up next to the repair site.

However, traditional CLS equipment can not be set up close to the repair site due to the large size of the equipment.

Therefore, the material loss in the hose, installation work and manufacturing costs are reduced by Mini-CLS equipment.

Development and Application of New Drum Type Rotary Slag Testing Apparatus

S. UCHIDA, M. NAKATSUKASA and N. KUROZUMI

Abstract

A drum type rotary slag testing apparatus has been used to evaluate the slag erosion resistance of refractories.

This apparatus has some problems such as the change in slag chemical composition caused by the dissolution of specimen components into slag during testing, difficult control of testing temperature, and operation under sever working conditions such as high heat emission, slag gas attack and dust air pollution.

In order to resolve these problems, a new apparatus with an automatic slag feeding/draining system and an automatic temperature controller was developed.

The operator's burden was lightened and accurate evaluation of high slag resistance refractories which had been difficult with the conventional method was made possible.

Information on Products of Associated Companies

Shinagawa Rongyuan Refractories Co., Ltd.

M. OGATA

Abstract

Shinagawa Rongyuan Refractories (SRR), located in China, is a new joint venture company consisting of Shinagawa Refractories (SRC) and Rongyuan Magnesite (RMC).

SRR is equipped with a Cold Iso-static Press (CIP) and is producing continuous casting nozzles or tap-hole sleeves for converters.

SRR aims to expand sales in the Chinese CIP refractories market by combining RMC's production and sales forces with SRC's technologies.

ITM Co., Ltd

M. FUJII and R. MAEDA

Abstract

ITM Co., Ltd. manufactures both FIBEREXEL (FXL / Amorphous fiber) and FIBERMAX (FMX / Polycrystalline fiber) in our plant in Japan.

FIBERMAX has improved thermal stability over traditional ceramic fiber due to its mineral composition.

The demand for FIBERMAX has therefore been increasing in recent years.

The outstanding characteristics of FIBERMAX products. - Stability at high temperature : Low thermal shrinkage over long periods. <1% - Stability in reducing atmosphere : High alumina content. - Low impurities : Na + Fe <300ppm - Excellent thermal shock resistance - Exceptional strength : High bulk density and high temperature creep strength. - FIBEREXEL is the trademark of ITM amorphous fiber. - FIBERMAX is the trademark of ITM polycrystalline fiber.

Isolite Insulating Products Co., Ltd.

K. NAKASHIMA

Abstract

Ceramic fiber is a fibrous lightweight material with refractoriness.

Today, there are various grades in ceramic fiber and they are used for various furnaces operated at temperature higher than 1350C due to effective thermal insulation and low heat capacity.

Among various grades ceramic fiber, the most suitable one for high temperature furnace is the grade of alpha alumina and mullite content.

But this grade has disadvantage of higher cost.

Therefore, most common practice is to use a combination of lower cost grade of ceramic fibers.

Teikoku Yogyo Co., Ltd.

Y. NASU and K. IGAMI

Abstract

Teikoku Yogyo Co., Ltd. is a group company of Shinagawa Refractories Co., Ltd. As a production site in west Japan, it produces all kinds of monolithic products such as castable, mortar and precast block.

Inorganic paint and adhesive products are very unique to Teikoku Yogyo.