Corrosion Behavior of WC-Co and WC-Ni in 3.5% NaCl at Increasing Temperature

Abstract

Tungsten carbides (WC) are widely used as wear resistant components such as seal, valves, rings, nozzle and bearings. But in some processing operations, the environment necessarily includes severe corrosion or extremes of temperatures. In paper reveal, the corrosion performance of commercial cobalt tungsten carbide (WC-6%Co) and nickel tungsten carbide (WC-9%Ni) in seawater with 3.5% salinity. The experiment was performed in four different temperatures (20°C, 40°C, 60°C and 80°C) and the surface structure by corrosion attack was reveal under SEM. TheIcorrvalue of WC-9%Ni is lower than WC-6%Co, elucidate that WC-9%Ni is better in corrosion resistance compare to WC-6%Co. As the temperature increased, the corrosion rate for every material increased as expected. Decreasing in hardness value for both materials reveal that, the material’s hardness decrease after corrosion has attacked.

A Comparison between Hardness, Corrosion and Wear Performance of APS Sprayed WC-CoMo and WC-Co Coatings

“…The applied potential was varied between -1000 mV and +1500 mV versus Saturated Calomel Electrode (SCE) at a scan rate of 0.16 mV s -1 with the aid of a Potentiostat/Galvanostat (VoltaLab PGP201). Similar investigations were done by Ismail et al [6]. The sliding wear tests were conducted on a Pin-on-Disk equipment (CSM Instruments-Tribometer) using a WC-Co ball, a force of 10 N, a linear speed of 31 cm s -1 with a radius of 6 mm and 100 000 laps.…”

Electroless Plating of Ni Nanoparticles on WC to Assist Its Pressureless Sintering of WC-Ni Cemented Carbide with Enhanced Mechanical and Corrosion-resistant Performance

“…Compared with the corrosion performance and Rockwell hardness of WC-9%Ni tested at 40 ℃ in the Ref. [38], the alloy properties of different Ni contents prepared by WC-EP in this study were all lower than those in the literature, and the hardness only decreased by 2.4HRA compared with that in this study, showing no significant difference, self-corrosion potential (E corr ) was -0.297 V, with a large gap, the specific reasons for which need to be further explored. In addition, Compared with the corrosion resistance of WC-12wt%Co in NaCl solution in litera- ture [39] , The highest value of polarization resistance (R p ) in the literature was 13.42 Ω and the data of chemical plated WC@18.8wt% Ni was 2.9 times higher.…”

Comparison on the immersion corrosion and electrochemical corrosion resistance of WC–Al2O3 composites and WC–Co cemented carbide in NaCl solution

“…The corrosion resistance of materials used in corrosive environment is a very important technical index, which is usually studied by electrochemical method. Electrochemical corrosion resistance of WC-based hardmetals depends on several factors, which includes the binder composition, 18,19 WC grain size, [20][21][22] binder content 23 and additives. 24,25 Human et al 23 conrmed that WC-Co cemented carbide possessed the higher anti-corrosion ability with the decrease of Co content.…”