采用超声喷丸(USSP)技术对Cr5Mo钢表面进行纳米化处理, 研究了试验钢表面的组织及显微硬度, 并对超声喷丸前后试样在含H2S流动去离子水溶液中的流动加速腐蚀性能进行了研究, 并对腐蚀产物膜的微观形貌进行了观察。结果表明: 经USSP处理后, 试样表面形成了一定深度的纳米晶层, 该晶层内的平均晶粒尺寸约为20 nm; 表面纳米化能够明显提高试样表层的显微硬度, 并且处理时间越长, 显微硬度越大, 变形层厚度越大; 与原始粗晶试样相比, 表面纳米化试样的抗流动加速腐蚀性能增强, 表面生成的腐蚀产物膜较致密; 随着USSP处理时间的延长, 腐蚀产物膜的致密度和完整性变差, 耐蚀性能逐渐下降。

Surface nanocrystallization was carried out on Cr5Mo steel by using an ultrasonic shot peening (USSP) technique. The microstructure and microhardness on surface layer were studied, and the flow-accelerated-corrosion properties of the sample with and without USSP treatment in flow deionized water solution containing H2S were conducted, the morphology of corrosion product film was also observed. The results show that nanaocrystalline layer with a certain depth and mean grain size of 20 nm was obtained on Cr5Mo steel surface after USSP treatment. The microhardness of the sample surface was remarkably enhanced by surface nanocrystallization, the long the treatment time, the high the microhardness, and the large the deformation layer thickness. Compared with the sample without USSP treatment, flow accelerated corrosion (FAC) resistance performance of the samples with USSP treatment was promoted and the corrosion product film was compact. Tightness and integrality of the film decreased with the increase of USSP treatment time, as thus, the corrosion resistance declined gradually.