Sumitomo Metals Receives 55th Okochi Memorial Foundation Grand Production Prize for its Development of Advanced Stainless Boiler Tube for
Ultra-Supercritical (USC) Coal-Fired Thermal Power Plants

Today, Sumitomo Metal Industries, Ltd. (Sumitomo Metals) received the 55th Okochi Memorial Foundation Grand Production Prize for its development of advanced stainless boiler tube for ultra-supercritical (USC) coal-fired thermal power plants. The Company was awarded for development and practical application of this boiler tube that had made a breakthrough in enabling an advance from the conventional supercritical (SC) power plant to the USC plant, for the first time in about 30 years. The developed boiler tube has been globally standardized by enabling to achieve highly energy-efficient operation of thermal power plants throughout the world, particularly by significantly contributing to reduction of CO2 emission and coal usage.

The Okochi Memorial Foundation Grand Production Prize, the highest honor among the Okochi Production Prizes, is awarded to an outstanding industrial achievement that is based on distinguished innovative corporate research. Sumitomo Metals is pleased to receive this award for the third time, after receiving a second two years ago.

1.Development Background

Demand for electricity is expected to rise in the medium to long-term around the world and coal-fired thermal power generation is one of the important methods to satisfy this demand. From the viewpoint of energy-saving and reduction of CO2 emission, the biggest challenge facing operators of coal-fired power facilities is to improve energy efficiency. In order to achieve higher energy efficiency of power generation, a critical factor is to attain high temperature and high pressure of steam to be generated in the boiler. Conventionally, the heat efficiency of power plant had stayed at around 41% in the SC condition with a temperature of 566 degrees Celsius and pressure of 24.1MPa. In order to attain power generating efficiency of about 43%, under the more rigorous USC conditions, and to realize the USC power plants, a boiler tube with resistance to steam oxidation and outer high-temperature corrosion, in addition to having high-temperature resistance, is indispensable.

2. Features of Developed Technology

(1) Development of advanced steel pipe materials

In a conventional SC plant, the steel containing 18% chromium (18%Cr) had been used for the boiler tube. Sumitomo Metals developed fine-grained 18%Cr steel by using its unique control technology to precipitate niobium carbide and attained high temperature strength and steam oxidation resistance. The Company then advanced this technology by developing significantly stronger steel that contains copper. The resulting new 18%Cr steel has shown the highest-strength achieved for steel for this application.

Further development by Sumitomo Metals, with the objective of enabling usage in boiler tube for high-sulfur content coal combustion boiler, succeeded through use of nitrogen and niobium in developing a new 25%Cr steel. This steel excels in high-temperature corrosion resistance.

After long-term field tests, these newly-developed steel tubes have been registered in the major world standards.

(2) Development of mass production technology

In terms of manufacturing technology, these steel tube materials require use of unprecedented high-temperature heat treatment and high-reduction cold drawing processing technology. In order to enable mass production, Sumitomo Metals developed such technology, in addition to improving the performance of the heat treatment furnace.

In 2007 Sumitomo Metals constructed a new stainless boiler tube plant, where such mass production technologies have been introduced, at the Steel Tube Works (Amagasaki). The plant is currently operating at full capacity.

3. Results

Sumitomo Metals'development of the boiler tube has played an invaluable role in realizing the construction of USC power plants. A total of 191 USC power plants, including 22 in Japan, have already adopted, been supplied with, or decided to adopt the tube. Adoption of the improved boiler tube has contributed to reduce CO2 emission and coal usage at every location.

Demand for stainless boiler tube for the USC power plants has been sharply rising. Sumitomo Metals has an 80% global share for such tube.

 

Information regarding the Prize and Award Ceremony

1.Okochi Memorial Foundation Prize

Commemorating Dr. Masatoshi Okochi's services to academic societies and industries, the Okochi Memorial Foundation was established in 1954 and has presented the Okochi Memorial Prize with the objective to "promote science and technology for production," which was the late Dr. Okochi's wish. The Okochi Prize recognizes notable contributions in the areas of production engineering, production technology research and development, and the implementation of high-level production methods in Japan.

2.Prize awarding ceremony

Stainless Boiler Tube for Ultra-Supercritical (USC) Power Plants