1. Development of new steel non-oriented electrical steel
Cold-rolled electrical steel is one of the three major products of New Steel. In 2008, Xingang began to independently develop non-oriented electrical steel manufacturing technology, which was gradually carried out from smelting, continuous casting, hot rolling, cold continuous rolling and continuous coating. In 2010, the whole line was opened, and mass production was realized that year. The design capacity of the continuous production line is 400,000 t/year, and the production and sales volume after 2014 has reached more than 500,000 tons. In order to meet the national energy conservation and environmental protection policies and the development requirements of high efficiency, energy saving and miniaturization of electromechanical products such as compressors, motors, power transformers and precision motors, since 2014, Xingang has independently developed high-efficiency and high-grade non-oriented electrical steel manufacturing technology, 2015 The annual trial system was successful, and mass production was achieved that year. In March 2015, the new steel normalized pickling line and the 1450 mm single-stand reversing mill were built. The new steel non-oriented electrical steel grades gradually expanded, and the original low-grade non-oriented electrical steel was transformed into high-efficiency and high-grade non-oriented. The development direction of electrical steel and medium and low grade electrical steel is supplemented. In 2015, the output of double high products was 50041 t, accounting for 11.49% of the output of electrical steel in 2015. In 2016, the output of double high products reached 110,000 tons.
New Steel has successfully developed 19 grades of non-oriented electrical steel, including 14 high-efficiency and high-grade steels, and can also develop special special grades according to customer needs.
2. Non-oriented high-efficiency electrical steel production process
Compared with ordinary non-oriented electrical steel, the production process of non-oriented high-efficiency electrical steel mainly increases the normalization process of hot-rolled sheet.
In order to ensure the excellent performance of non-oriented high-efficiency electrical steel, the production process must be strictly controlled.
1) Compared with medium and low grades, non-oriented high-efficiency electrical steel has stricter control requirements on the content of harmful elements such as carbon, sulfur, nitrogen and oxygen in steel. Reducing the type of inclusions and reducing the size of inclusions can reduce the resistance of grain growth during final annealing and reduce iron loss.
2) Adding some trace elements can reduce the grain boundary energy, obtain the final texture with favorable texture and improve the performance.
3) Due to the higher alloying degree of non-oriented high-efficiency electrical steel and the greater deformation resistance of the product, cold-rolling uses a single-stand reversible six-high mill with better plate shape control capability. The horizontal and vertical plates can be effectively effective. Guarantee.
4) Optimize the parameters of hot rolling, normalizing and continuous annealing, obtain the structure of favorable hot texture by obtaining the coarse hot rolled sheet structure, and finally realize the complete recrystallization annealing to ensure the product has high magnetic induction and low iron. damage.