Abstract: Based on industrial experiments, the modification effect of Ce content on inclusions in 201-J5 low nickel austenitic stainless steel and its influence on corrosion resistance and mechanical properties were systematically studied. As the Ce mass fraction increased from 0 to 61×10??, the inclusions in the steel gradually transformed from Al-Si-Mn-Ca-O and MnS to spherical Ce-Al-Si-O-S composite inclusions. The number density of inclusions decreased from 28.9 mm?2 to 16.2 mm?2, the area fraction decreased from 68.9×10?? to 39.8×10??, and the average size decreased from 4.9 μm to 4.4 μm. When the Ce mass fraction was 37×10??, the stainless steel exhibited the best corrosion resistance. When the Ce mass fraction increased from 0 to 37×10??, the corrosion weight loss rate of steel decreased from 0.078 g/(m2·d) to 0.038 g/(m2·d), and the breakdown potential increased from 128.1 mV to 147.6 mV, and the intergranular corrosion susceptibility was significantly reduced. In terms of mechanical properties, the addition of the rare earth element Ce refined the grain structure, increasing the grain size level from 6.0 to 6.6. Simultaneously, the tensile properties and impact toughness of the steel were improved, with the transverse tensile strength showing an increasing and then decreasing trend, the longitudinal tensile strength continuously increased, and the elongation after fracture steadily increased. The impact absorption energy reached a peak of 102 J at a Ce mass fraction of 34×10??. In addition, Ce effectively improved the high-temperature plasticity of the steel, eliminated the plastic deterioration phenomenon in the 1100–1150 ℃, and effectively suppressed the occurrence of peeling defects on the surface of hot-rolled plates. This study provides an important basis for the inclusion control and performance improvement of rare earth Ce in the industrial application of low nickel austenitic stainless steel.

Key words: 201-J5 stainless steel; rare earth cerium; modification of inclusions; corrosion resistance; mechanical properties