Evaluation of the corrosion resistance of a Ni-P coating deposited on additive manufacturing steel: A dataset

This article presents the data set obtained for the research work entitled “Effect of a Ni-P coating on the corrosion resistance of an additive manufacturing carbon steel immersed in a 0.1 M NaCl solution” [1]. Microstructural, mechanical, and electrochemical characterization (using the electrochemical impedance and electrochemical noise spectroscopy technique) is performed on a material obtained by additive manufacturing and the influence of a Ni-P coating on it. The layer sizes and hardness of the substrate are measured, as well as the thickness of the coating and its hardness, values for corrosion resistance, resistance to electrochemical noise and location indices are calculated. The data show an adequate deposition rate for the type of coating, as well as the increase in corrosion resistance when the coating is applied to the steel by additive manufacturing.

Surface engineering Specific subject area Corrosion Type of data Table  Image Figure How data were acquired SEM images are obtained using a Philips XL20 scanning electron microscope. Layer and coating thicknesses are measured using the free-access Imagej computer tool. The microhardness is obtained in a digital microdurometer model HVS-10 0 0. The structure of the material is characterized by X-ray diffraction and the data is obtained in a PANalytical X Ṕ ert Pro MPD diffractometer. Electrochemical impedance spectroscopy and electrochemical noise data are obtained on a Gill AC potentiostat/galvanostat using Sequencer software. Data format Raw Analyzed Parameters for data collection Electron microscopy images are obtained with 200 kV secondary electrons with a working distance of 7.4 mm. The microhardness of the additive manufacturing steel layers and the coating is measured by applying a load of 100 g with a time of 10 s. The structure of the coatings was evaluated employing x-ray diffraction at a room temperature of 25 °C, a range between 15 and 90 °is established, a time per step of 30 s, for a total scanning time of 7 min. In the corrosion study a three-electrode electrochemical cell is used, which is composed of an SCE electrode as reference, a graphite plate as the counter electrode and the sample as a working electrode. The sweep frequency for the electrochemical impedance spectroscopy data was from 10 4 to 10 −1 , acquiring 10 points/decade, a sine wave is used as a disturbance to the system with amplitude of 10 mV. In electrochemical noise, time series of 1024 points are obtained every 0.5 s. The electrochemical evaluation is carried out in a 0.1 M sodium chloride solution. Description of data collection Corrosion data is collected through the use of the Sequencer software. The layer size and coating thickness measurement is collected using the Imagej software. The microhardness data is collected manually. The XRD data is taken by the diffractometer. Data

Value of the Data
These data provide a look at the corrosion behavior of steel produced by additive manufacturing and the influence of a Ni-P coating applied on the material. These data provide the ability to predict the influence of chloride ions on additive manufacturing steel and on the applied Ni-P coating and its useful life, being useful for academics and researchers in the area of additive manufacturing, electrochemistry, surface engineering, and corrosion protection.  When evidencing a considerable increase in the corrosion resistance of the coated material, these coatings are proposed as favorable to be applied to this type of substrates under similar working conditions.

Data Description
In additive manufacturing steel three important areas were identified, Fig. 1 (scanning electron microscopy images), (a) shows the area of the first 2 layers of the steel by additive manufacturing, (b) shows the intermediate area of the material by additive manufacturing, and (c) shows the upper zone of the steel by additive manufacturing.
The synthesis of the coatings is made using a bath of: Nickel sulfate ( NiSO 4 ) 0.2 M, Sodium hypophosphite ( NaPOH 2 ) 0.25 M, Propionic acid ( Lead shot 1.13 × 10 −6 M, the pH of the solution is maintained at 4.5 at a temperature of between 86-88 °C, an activation of the test pieces is performed in 15% HCl. The immersion time in the bath was 3.5 h under stirring. Fig. 2 shows an electron microscopy image of the Ni-P layer deposited on the steel, Table 1 shows the data resulting from the measurement of the thickness of the coating, and its distribution in Fig. 3 . Table 2 shows the microhardness data of each of the layers of the material produced by additive manufacturing (data resulting from the measurement in the cross-section), and the microhardness data of the coating. Table 3 shows the data set of the diffractograms presented in Fig. 3 . Fig. 3 shows 2 diffraction patterns obtained for the Ni-P coating of amorphous nature. Table 4 shows the data set in Fig. 4 (Z ´i s the real impedance, Z´ís the imaginary impedance). Fig. 4 a shows the Nyquist diagram for steel by additive manufacturing, Fig. 4 b shows the data for coated steel. Table 5 shows the data for the impedance bode diagram in Fig. 5 . Fig. 5 a shows the data in the impedance boundary diagram for the uncoated steel and Fig. 5 b for the coated material.   Table 6 shows the data for the phase angle bode diagram of Fig. 6 . Fig. 6 a shows the data for the phase angle bode diagram for additive manufacturing steel, Fig. 6 b shows the data for the coated material.   Table 7 shows the noise resistance data and the location index calculation for steel by additive manufacturing and Ni-P coating [2] .

Experimental Design, Materials, and Methods
SEM images are obtained in a Philips XL 20 electron microscope at an acceleration voltage of 200 kV and a WD of 7.4 mm, the metallographic preparation is carried out using conventional polishing techniques based on the ASTM E3 [3] , the attack Chemical used to reveal the microstructure was 2% Nital. Coating thickness is measured from SEM images in free software ImageJ [4] .      The microhardness data is obtained in a digital microdurometer model HVS 10 0 0 following the guidelines of the ASTM E384 standard [5] using a 100 g load at 10 s hold with a diamond tip vickers indenter. Fig. 3 shows the diffractograms for 2 samples of the electroless nickel plating steel, these are obtained in a PANalytical X'PERT PRO MPD X-ray diffractometer in a range of 15 °to 90 °, with time per step of 30 s, and a total scan time of 7 min, this test is applied at an ambient temperature of 25 °C.
The monitoring of the corrosion state is carried out using the non-destructive techniques of electrochemical impedance and electrochemical noise spectroscopy, for this purpose a Gill AC potentiostat/galvanostat is used. A three-electrode electrochemical cell is implemented, composed by a SCE electrode as reference, a graphite plate as counter electrode and the specimen as working electrode. The working electrolyte was 0.1 M NaCl (low-medium aggressive corrosion) [6] . The sweep frequency for the electrochemical impedance spectroscopy data was from 10 4 to 10 −1 , acquiring 10 points/decade, a sine wave is used as a disturbance to the system with amplitude of 10 mV. In electrochemical noise, time series of 1024 points are obtained every 0.5 s. The DC trend of the time series was eliminated using linear methods reported by Lentka and Smulko in [7] .

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships which have, or could be perceived to have, influenced the work reported in this article.