Abstract：In order to explore the factors affecting the production stability of 10B21 steel, improve the quality of steel and meet the needs of customers, the inclusions of clean steel in the whole process were sampled and analyzed. The results show that there are mainly seven types of inclusions in each station of the whole process, namely CaO-Al2O3-MgO-CaS-TiN, CaO-Al2O3-MgO-CaS, Al2O3, MnS, MnS-Al2O3, Al2O3-TiN and MnS-TiN. Except that the type of sample inclusions in converter station is relatively complex, the inclusions in other stations are mainly CaS-Al2O3-MgO-CaO-TiN. The oxygen and nitrogen content fluctuates greatly in different furnace times, especially the control of the oxygen content at the end of the converter is unstable, the inclusions change greatly in the LF refining process, and the size generated after soft blowing operation is 80-100 μm, the main component of which is CaO-Al2O3-MgO-CaS-TiN. That is, with calcium oxide and alumina as the nucleation center, magnesium oxide is accompanied outside and wrapped by calcium sulfide and titanium nitride. The inclusions of this component begin to form after LF refining calcium feeding line. Due to the low fluidity of refining slag, poor coverage effect on liquid steel, secondary oxidation is easy to occur, resulting in the obvious aggregation and growth of inclusions in the soft blowing stage.
2022, Vol. 41 
