To address the corrosion protection issues for hot components of high-end equipment in extreme service environments, the C276 alloy coating was deposited on the surface of 304 stainless steel via high-velocity air fuel (HVAF) spraying. The extreme conditions of 1000 °C temperature, an atmosphere containing 6% HCl, and a flow rate of 30 m/s were simulated in the study using a high-temperature airflow corrosion erosion device. The C276 coating and the 304 stainless steel substrates were subjected to a corrosion test for 25 min. The surface phase composition, element distribution, corrosion product characteristics, and cross-section structure of the samples before and after corrosion were systematically analyzed by means of a scanning electron microscope, an energy dispersive spectrometer, and an X-ray diffractometer. The mechanism of high-temperature chlorination corrosion was deduced through thermodynamic and kinetic analysis. The results show that compared with 304 stainless steel, the C276 alloy coating exhibits better corrosion resistance in an extremely high-temperature environment containing HCl, and the average weight gain and growth rate of the corrosion layer were lower. The main corrosion products on the C276 coating surface are Fe₂O₃, FeO, FeCl₂, NiO, and Cr₂O₃, among which the oxides of Ni and Cr form a continuous and dense protective oxide layer that effectively inhibits the intrusion of corrosive media. The high-temperature HCl corrosion follows the ‘chlorination–oxidation’ cycle mechanism, and Cl₂ plays a catalytic role in the reaction and accelerates the corrosion process.

The most important segment of the electric arc furnace (EAF) steelmaking process is the stirring and decarburization of the molten bath during the oxidation stage, with the bath temperature typically ranging from 1550 to 1600 °C. The coherent jet is a key factor influencing the stirring and decarburization of the molten bath. The factors affecting the impact capability of coherent jets have been widely studied, including the nozzle flow parameters and arrangement methods. However, there are few studies on the combustion chamber structure of the coherent jet oxygen lance. In order to study the effect of the combustion chamber structure on the characteristics of the coherent jet, a method combining numerical simulation and combustion experiments is used to study the flow fields of the coherent jet for a combustion chamber under different length and inclination angle conditions. The results show that the flow field characteristics of the coherent jet are influenced by the length and inclination angle of the combustion chamber. Compared with the coherent jet oxygen lance without a combustion chamber, the potential core length of the main oxygen jet under the short-distance horizontal combustion chamber condition is longer, but the potential core length of the main oxygen jet with the excessively long horizontal combustion chamber is shorter. The influence of the inclination angle on the potential core length of the main oxygen jet is complex. The influence mode is different depending on the length of the combustion chamber. Finally, it is found that the combined horizontal and inclined combustion chamber can achieve the best effect on prolonging the potential core length of the main oxygen jet.