Sumitomo Metals Receives Monodzukuri Nippon Grand Award for Efficient
- Manufacturing Technology for High Quality Very Thick Steel Plate -

Sumitomo Metal Industries, Ltd. (Sumitomo Metals) has received the Minister of Economy, Trade and Industry’s Prize in the Manufacturing and Production Process Category of the 4th Monodzukuri Nippon Grand Award for development and commercialization of technology to efficiently manufacture high quality very thick steel plate by continuous casting. The award ceremony was held on February 15, 2012 at the National Graduate Institute for Policy Studies in Minato-ku, Tokyo.

1. Development Background
Steel plate as thick as 100 mm or more is used for dies, large industrial machinery, bridges, and offshore structures. The steel slightly shrinks when it solidifies. Thus, when slabs, the base metal steel plate, are cast, porosity formed with a large amount of pores of about 2 mm in diameter is formed at the central part of the molten steel. If the steel plate is not too thick, porosity is compressed and does not cause any serious problem. However, when very thick steel plate is manufactured from slabs as thick as about 300 mm by a continuous casting machine for mass production, a reduction ratio* that is sufficient to compress porosity is not obtained. This is why slabs made of large-section ingots are needed to manufacture very thick steel plates, resulting in low productivity and high costs.

2. Features of Awarded Technology
Sumitomo Metals installed a reduction roll inside a continuous casting machine at Kashima Steel Works and conducted a test to analyze the relationship between solidification and porosity formation. We then found out that the forming of pores can be efficiently reduced when the slab surface is compressed just before the central part of the slabs is completely solidified at the time when there is a sufficient difference in temperature between the cooled surface and the hot central part. This finding has enabled production of very thick plate by continuous casting for mass production. The new technology to reduce porosity forming by reduction within the continuous casting machine has been named the Porosity Control of Casting Slab (PCCS) technology. Development of the PCCS technology has enabled a reduction in production lead time from about three months to less than one month and cut costs significantly.

3. Future Developments
Sumitomo Metals plans to apply the PCCS technology to high grade very thick steel plate for the energy sector, which has high growth potential, and thereby ensure stable quality and short delivery time.

4. Reference
“ Monodzukuri Nippon Grand Award”
Monodzukuri is an art of making goods that has supported Japanese culture and industry.
The Monodzukuri Nippon Grand Award was established to recognize the development of monodzukuri and pass it on to the coming era by rewarding those individuals whose achievements are on the cutting edge of monodzukuri. Since 2005, the Ministry of Economy, Trade and Industry and three other ministries have been collectively promoting this Award.

Note*
The reduction ratio indicates how thinner the steel plate becomes after the hot rolling process.
(Thickness before hot rolling – thickness after hot rolling) / (Thickness before hot rolling) X 100(%)

<Graph 1: Manufacturing Process for Very Thick Steel Plate>

<Graph 2: PCCS Technology>

　<Picture>

(From left)
Dr. Kenji Taguchi (Steelmaking R&D Department, Sumitomo Metals’ Corporate Research & Development Laboratories)
Mr. Yoshihisa Shirai (Manager of Group, Stainless Steel & Titanium R&D Department, Corporate Research & Development Laboratories)
Mr. Sei Hiraki (Counselor, Intellectual Property Department)
Mr. Kozo Ota (General Manager of Quality Management and Production Planning Department, Kashima Steel Works, Steel Sheet, Plate & Structural Steel Company)　
Mr. Yukio Edano (Minister of Economy, Trade and Industry)
Mr. Rousei Satou (Plate Department, Kashima Steel Works, Steel Sheet, Plate & Structural Steel Company)
Mr. Naoki Tajima (Steelmaking Department, Kashima Steel Works, Steel Sheet, Plate & Structural Steel Company)
Mr. Seiji Kumakura (Manager, Steelmaking Department, Kashima Steel Works, Steel Sheet, Plate & Structural Steel Company)
Dr. Akihiro Yamanaka (Research Manager, Steelmaking R&D Department, Corporate Research & Development Laboratories)

(The following two award recipients could not attend the ceremony.)
Yasuhiro Satou (Bushan Technical Collaboration Department)
Takahiro Kamo (Manager, Plate Department, Kashima Steel Works, Steel Sheet, Plate & Structural Steel Company)

Titles and divisions in parenthesis indicate current titles and divisions.