Development of top high-grade non-grain-oriented silicon steels at Baosteel

The development,production and application of top high-grade non-grain-oriented ( NGO) silicon steels at Baosteel were introduced in this paper. Top high grades refer to the highest grades in the international silicon steel product standard and above. B35A230 and B50A250 were developed at Baosteel in 2009 and have been used in inverter compressors for air-conditioners,small transformers and big hydropower generators in the Three Gorges project. Smallbatch poduction of B35A210 and B50A230,which exceed the highest grades listed in the international silicon steel product standard,began in 2010. That was a breakthrough in the silicon steel making history in China. Presently,Baosteel’s high-grade NGO products have passed the strict qualifications of the three major electric power equipment manufacturers in China and the leading international power equipment suppliers like ALSTOM ,GE,SIEMENS,VESTAS,etc. These products are characterized by low iron loss,low anisotropy,good punchability and a high lamination factor. They have been used in the 770 MW hydropower generator at Xiluodu Power Station in the three gorges area,1 000 MW thermal power generators and 2. 5 MW wind power generators.