In order to verify the advantage of CaO⋅6Al 2 O 3 (CA 6 )-based refractories on the inclusions of aluminum deoxidized steel, the five refractories, CA 6 , alumina, spinel, and CA 6 -alumina and CA 6 -spinel composition refractories were prepared into crucibles, and then the laboratory smelting experiments were conducted. After experiment, the slag resistance of the crucible and the variation on inclusions in steel were characterized and discussed. A dense CaO⋅2Al 2 O 3 (CA 2 ) layer, which was produced by CA 6 reacting with the slag, was distributed between the original bricklayer and the slag layer, improving the slag resistance of refractories. Meanwhile, the 12CaO⋅7Al 2 O 3 (C 12 A 7 ), generated by the reaction between CA 2 and refining slag, would release much Ca into the molten steel. The Ca would react with inclusions to produce low melting point substance to float up and remove, contributing to the reduction of the proportion of large size inclusions. In addition, typical inclusions in steel smelted with CA 6 crucible were small-sized MgO⋅Al 2 O 3 inclusions, whereas those of other crucibles are MnS-MgO⋅Al 2 O 3 composite inclusions with MgO⋅Al 2 O 3 as the core, implying CA 6 may absorb sulfur during the smelting process.

In this study, to clarify the corrosion mechanism of CA6 based refractory by refining slag, the static crucible tests for CA6, CA6-Al2O3, and Al2O3 refractory, were carried out and the detail reaction processes were analyzed from the perspective of thermodynamic simulation and structural evolution. From the results, CaAl4O7 plays a vital role in the slag corrosion resistance of the three refractories. Regarding CA6 refractory, the double pyramid module in CA6 crystal structure was destroyed very quickly, leading to the rapid collapse of its structure to form the denser CaAl4O7 in high amounts. As a result, a reaction layer mainly composed of CaAl4O7 formed, which effectively inhibited the slag corrosion, so CA6 refractory exhibits the most excellent slag corrosion. Meanwhile, the formation of CaAl4O7 can also avoid CA6 particles entering the molten steel to introduce exogenous inclusions. For Al2O3 refractory, the generation of CaAl4O7 is much slower than that of CA6 and CA6-Al2O3 refractory, and the amount generated is also quite small, resulting in its worst slag corrosion among the three crucibles. Therefore, CA6 based refractory has excellent application potential in ladle refining and clean steel smelting.

In recent years, the accidents caused by the instability and failure of the steel structure of the bridge occur frequently. Therefore, the research on high-performance steel members is one of the key directions of the development of Engineering Technology in the 21st century. In this paper, the damage tolerance evaluation method based on the finite element calculation of crack growth is used to analyze the fatigue of the load-bearing carbon fiber suspender with cracks in the operation stage, to correctly evaluate the remaining life and the remaining safety of the component, and to effectively handle Grasp the status and disease development of the bridge, so we can take timely and targeted measures to ensure the safety of the bridge.