钢纤维是超高性能混凝土（ultra-high performance concrete, UHPC）的主要增强材料，为进一步提高钢纤维的耐腐蚀性，推进UHPC在腐蚀环境中的使用，从增强钢纤维的耐腐蚀性出发，对钢纤维在150、300、450和600 ℃ 4种不同温度下进行热处理，并用作原材料制作超高性能混凝土。将UHPC、钢纤维（含对照组）置于3.5%氯离子溶液中浸泡100 d，采用电化学方法和微观形貌分析法对钢纤维的耐腐蚀性进行分析。结果表明，随着热处理温度的升高，改性钢纤维的耐腐蚀性逐渐增强，钢纤维经过600 ℃热处理后氧化皮最耐腐蚀，表面形貌最致密，但耐腐蚀性能下降程度在所有热处理温度中最大；改性钢纤维浸泡后，原材料钢纤维表面锈层未出现明显腐蚀产物FeOOH的标准形态；在150、300、450 ℃热处理温度下具有双相结构，随着热处理温度的升高，α-FeOOH减少，γ-FeOOH增多；在600 ℃热处理温度下，钢纤维的锈层除了生成α-FeOOH γ-FeOOH之外，还生成了促进腐蚀的β-FeOOH。

The corrosion resistance of steel fibers, the primary reinforcing material in ultra-high performance concrete (UHPC), was enhanced by subjecting them to heat treatment at different temperatures (150 ℃, 300 ℃, 450 ℃, and 600 ℃). This treatment, aimed at advancing the corrosion resistance of steel fibers and promoting the use of UHPC in corrosive environments, involves incorporating the modified steel fibers into the raw materials for UHPC production. Subsequently, UHPC and steel fibers (including a control group) were immersed in a 3.5% chloride ion solution for 100 days. Corrosion resistance analysis of the steel fibers is conducted using electrochemical methods and microscopic morphology analysis. The results indicate that, with increasing heat treatment temperature, the corrosion resistance of the modified steel fibers gradually improves. After undergoing treatment at 600 ℃, the oxide scale on the steel fibers exhibits the highest corrosion resistance and the most compact surface morphology. However, the degree of corrosion resistance declines significantly at this temperature compared to all other heat treatment temperatures. Following immersion, no apparent standard form of corrosion product FeOOH is observed on the surface rust layer of the original steel fibers. At heat treatment temperatures of 150 ℃, 300 ℃, and 450 ℃, the rust layer displays a dual-phase structure, with a decrease in α-FeOOH and an increase in γ-FeOOH as the treatment temperature rises. At a heat treatment temperature of 600 ℃, the rust layer on the steel fibers generates not only α-FeOOH and γ-FeOOH but also β-FeOOH, which promotes corrosion.