**Chaonan Lei 1, Xudong Chen 1, Yusheng Li 2, Yuefeng Chen <sup>1</sup> and Bin Yang 1,\***


Received: 29 May 2019; Accepted: 2 August 2019; Published: 8 August 2019

**Abstract:** The corrosion resistance of a SA106B carbon steel with a gradient nanostructure fabricated by rotationally accelerated shot peening (RASP) for 5, 10, 15 and 20 min was investigated. Electrochemical tests were carried out in the 0.05 M H2SO4 + 0.05 M Na2SO4 and 0.2 M NaCl + 0.05 M Na2SO4 solutions. The experimental results showed that the sample RASP-processed for 5 min exhibited the best corrosion resistance among them. TEM analysis confirmed that the cementite dissolution and formation of nanograins, which improved the corrosion resistance of the steel. Prominent micro-cracks and holes were produced in the samples when the RASP was processed for more than 5 min, resulting in the decrease of corrosion resistance.

**Keywords:** carbon steel; rotationally accelerated shot peening; nanocrystalline; corrosion resistance
