Salt-Fog Corrosion Behavior of GCr15 Steels Treated by Ultrasonic Strengthening Grinding Process

Abstract

In this paper, the corrosion resistance of four GCr15 steel samples has been investigated. Three samples were initially surface-treated by ultrasonic shot peening (USP), a dry ultrasonic strengthening grinding process (DUSGP), and a wet ultrasonic strengthening grinding process (WUSGP), respectively, while another one was only polished. Then, all the processed samples were subjected to salt spray corrosion. Sample properties, such as capacitance arc, self-corrosion potential (Ecorr), self-corrosion current density (Icorr), corrosion morphology, and corrosion products were analyzed. Results show that the sample treated by WUSGP has the best corrosion resistance, which can be attributed to the high dislocation density, small grain size, needle-like and lath-like shape of martensite content formed in the treatment, which hinders Cl− from eroding the matrix. The obtained corrosion pits and cracks in Sample WUSGP show a width of approximately 1.4 µm and 2.1 µm, respectively, degrading 78% and 75% compared to polishing. The possible corrosion mechanism of the samples has been discussed. The findings denote that the treatment fused ceramic balls, strengthened liquid, and corundum in USP could be an efficient method to improve the corrosion resistance of some mechanical parts.

Preparation of a Ni-P-nanoPTFE Composite Coating on the Surface of GCr15 Steel for Spinning Rings via a Defoamer and Transition Layer and Its Wear and Corrosion Resistance

“…(3) The coating structure is detected by Empyrean X-ray diffractometer, using Cu target Ka radiation, accelerating voltage is 40 KV, the working current is 40 mA, X-ray incidence wavelength L = 0.1542 nm, the scanning speed is 6 • /min, the step size is 0.02 • /s, and angle (2θ) is 20~80 • . (4) The chemical composition of the coating is measured by the energy dispersion spectrometer that comes with the above scanning electron microscope, and the test elements are Ni, P, and F. (5) The friction and wear performance is measured by UMT-3 reciprocating friction testing machine, the friction pair is selected using a GCr15 steel ball with a diameter of 10 mm, and the microhardness is 810 HV. The load is set to 10 N, the reciprocating frequency is 2 HZ, and the friction stroke is 5 mm.…”

“…At present, the commonly used surface treatment technologies for GCr15 steel include thermal spraying, thermal diffusion, vapor deposition, electroless plating, electroplating, and laser texturing, among others [ 5 , 6 , 7 ]. Fang et al [ 8 ] thermally sprayed a Ni60A coating on the surface of GCr15 steel and carried out an induction remelting treatment; the hardness of the coating was as high as 818 HV.…”

The Tribological Properties of 30CrMnSiA Bearing Steels Treated by the Strengthening Grinding Process under Lubrication Wear

“…The alumina powder with a particle size of 1.3 µm and an average Vickers hardness of 2.2 × 10 5 MPa was used as the abrasive powder. The strengthening liquid was composed of borax (i.e., Na 2 B 4 O 7 ·10H 2 O), triethanolamine (C 6 H 15 NO 3 ), benzotriazole (C 6 H 5 N 3 ), and distilled water [ 30 ]. The jetting distance of abrasive materials was set as 90 mm, and the processing time was 15 min.…”

Enhanced Strength–Ductility Synergy Properties in Selective Laser Melted 316L Stainless Steel by Strengthening Grinding Process

“…The mixed abrasive is driven by the compressed gas or an ultrasonic actuator. Recent evidence suggests that the grain refinement, microhardness, and misorientation density of the treated surfaces can be significantly increased via the impact of the mixed abrasive (diameter less than 1 mm) for a short time, such as 3 min [ 37 , 38 ]. Increasing the grain refinement, microhardness, and misorientation density will also be accompanied by compressive residual stress, which is believed to be beneficial to improving the mechanical properties [ 39 ].…”