Researchers have produced a special type of steel that can tolerate high temperature for different time durations. This new modified steel will be very handy in building steam generator for breeder reactors1.
Many concerns have been reported on the poor performance of the fusion welds, especially in the thick components of the steel in the conventional fossil fuel fired power plants due to cracking in and around the weld joint. In search for better steel, the researchers chose modified 9Cr-1Mo ferritic steel. They exposed it to varying temperatures and studied its microstructure in details.
The researchers found the stability of its microstructure while exposing it to service temperatures in the range of 773-873 K for different time durations. A detailed microstructural and microchemical analysis of the secondary phases was then carried out using optical and electron microscopy techniques.
The microstructural observations, supported by hardness measurements showed that the lath morphology of the tempered martensite was retained even after 10, 000 hours of aging.
The authors of this work from: Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India.
