Surface integrity, corrosion resistance, and low-temperature impact property of FH36 marine steel subjected to ultrasonic surface rolling process

The service performance of FH36 marine steel subjected to ultrasonic surface rolling processing (USRP) in terms of surface integrity, corrosion resistance, and low-temperature impact property was investigated. The results demonstrated that the surface integrity of FH36 steel after USRP was reconstructed with the surface roughness declined to 0.117 μm by 88.7%, the average grain diameter refined to 2.77 µm by 31.8%, the surface hardness improved to 256 HV 0.1 by 39.9%, and the compressive residual stress introduced up to − 172 MPa. Due to the reduced surface roughness, introduced work hardening, and compressive residual stress, the FH36 steel after USRP obtained the excellent corrosion resistance with the corrosion current density declined up to 35.3% and the polarization resistance raised up to 34.8%. While the FH36 steel treated by USRP showed a decrease in the low-temperature impact property, as a result of the reduced high angle grain boundaries, improved surface hardness and reduced surface roughness. Meanwhile, the grain refinement and compressive residual stress induced by USRP were favorable to the low-temperature impact property of FH36 steel. Graphical abstract