Surface Roughness Of Carbon Steel Research Articles

Preparation and performance of a new silylated functional carbon quantum dots corrosion inhibitor

Adding green corrosion inhibitors to prevent the pickling process is critical to both corrosion of carbon steel and its environmental protection. Carbon quantum dots(CDs) corrosion inhibitors prepared using a hydrothermal method are considered promising candidates for carbon steel corrosion protection. Here, a new high-efficiency silylated functional carbon quantum dot (CDCA-Si-Pei) was prepared by hydrothermal method and evaluated for its corrosion inhibition performance as a corrosion inhibitor for carbon steel in hydrochloric acid solution (1 M HCl). Atomic force microscopy (AFM) and scanning electron microscopy (SEM) analysis revealed that the surface roughness of carbon steel treated with CDCA-Si-Pei was significantly reduced, the surface was free of corrosion products, and the adsorption mechanism of CDCA-Si-Pei was chemical and physical co-adsorption. The experimental results show that CDCA-Si-Pei is a highly efficient and stable inhibitor with obvious anti-corrosion effects, especially at a concentration of 10 mg/L and its corrosion inhibition rate of 96.34 % and 94.79 % after three months of placement.

Effect of Surface Roughness on Crystal Size of Manganese Phosphate Coating of Carbon Steel.

In this study, the correlation between surface roughness of carbon steel and crystal size of manganese phosphate coatings has been investigated. The microstructure and surface morphology of the coatings were analyzed by SEM, XRD. The surface roughness test was carried out in order to calculate Ra value by atomic force microscopy (AFM). Also, the tribology property of manganese phosphate coating was tested by ball-on disk. XRD showed that (Mn,Fe)5H₂(PO₄)₄·4H₂O in manganese phosphate coating layer was formed by the chemical reaction between manganese phosphate and elements in carbon steel. Also, (Mn,Fe)5H₂(PO₄)₄ · 4H₂O was observed to be formed in all manganese phosphate conversion coating. With regard to the effects of surface roughness on manganese phosphate coatings, it can be seen that there is an increase of the crystal size on manganese phosphate coating as the surface roughness of carbon steel decreased. The increase of crystal size by the surface roughness had effect on the tribology property and electrochemical property. It was approved that friction coefficient of manganese phosphate coating is remarkably improved as the surface roughness of carbon steel become rough.

Sulfonated chitosan as green and high cloud point kinetic methane hydrate and corrosion inhibitor: Experimental and theoretical studies

In this work sulfonated chitosan (SCS) was introduced as a promising green kinetic methane hydrate and corrosion inhibitor to overcome the incompatibility problem between inhibitors. Evaluation of hydrate inhibition performance of SCS with high-pressure autoclave and micro-differential scanning calorimeter revealed that hydrate formation was delayed 14.3 ± 0.2 times and amount of hydrate formed was decreased to 30 % compared to water. The weight loss experiments showed that SCS provides corrosion inhibition efficiency of 95.6 ± 0.1 at 5000 ppm concentration. SCS is able to increase polarization resistance and decrease corrosion current density according to electrochemical measurements. Study of surface morphology by SEM-EDX and profilometer showed that SCSs suppress corrosion rate and reduce the surface roughness of carbon steel. Quantum chemical study confirmed that the pendant groups caused by chitosan modification interact with carbon steel surface. The findings of this research can provide new opportunities to develop biodegradable materials as KHIs/CIs for flow assurance in oil and gas pipelines.

Influence of surface roughness on the electrochemical behavior of carbon steel

The effect of the surface roughness of carbon steel on corrosion properties was investigated using electrochemical tests, and surface and Kelvin probe force microscopy (KPFM) analyses. The results of electrochemical tests show that the corrosion rate of carbon steel is increased as the surface roughness increases. It was estimated using KPFM measurement that the difference in the Volta potential between the peak and the valley increased with increasing surface roughness. As the peak has a lower potential than that of the valley, the peak acts as an anode. The surface roughness affects the Volta potential, and the Volta potential difference is inversely proportional to electron work function (EWF). The larger difference in Volta potential between the peak and valley on the rougher surface and the smaller EWF accelerated the micro-galvanic corrosion between them. The surface analyses reveal that corrosion initiated along the peak lines. The results from this study suggest that an increase of surface roughness leads to a decrease of the corrosion resistance.

상대재료의 표면거칠기에 따른 PTFE와 UHMWPE의 마찰 및 마멸 특성

Understanding of the tribological characteristics of polytetrafluoroethylen (PTFE) and ultra-high-molecular-weight polyethylene (UHMWPE) is crucial for their applications such as bearing and total joint replacement. In this work, the effect of the surface roughness of carbon steel on the tribological behaviors of PTFE and UHMWPE was experimentally investigated by using block-on-ring tribotester with friction force monitoring capability. It was found that that the amount of material transfer layers of PTFE formed on the carbon steel was significantly larger than those of UHMWPE, which was responsible the lower friction coefficient of PTFE. It was also concluded that the effect of surface roughness of carbon steel on the friction coefficient of UHMWPE was more significant than that of PTFE. For UHMWPE, it was found that the effect of surface roughness of counterface was varied with respect to applied normal force and sliding as well. Based on Archard's wear law, the wear coefficient of PTFE and UHMWPE was calculated to be <TEX>$3{\times}10^{-5}$</TEX> ~ <TEX>$8{\times}10^{-5}$</TEX> and <TEX>$7{\times}10^{-6}$</TEX> ~ <TEX>$2{\times}10^{-5}$</TEX>, respectively.

ELECTROLYZED WATER AND ITS CORROSIVENESS ON VARIOUS SURFACE MATERIALS COMMONLY FOUND IN FOOD PROCESSING FACILITIES

ABSTRACT ASTM A‐36 medium carbon steel, 110 copper, 3003‐H14 aluminum, polyvinylchloride (PVC) type 1 and 304 stainless steel coupons were immersed in electrolyzed (EO) water, chlorine water, modified EO water and deionized water for a period of 8 days, and the properties of these types of water, weights and surface roughness of the coupons were monitored. EO water significantly increased (P &lt; 0.05) the surface roughness of carbon steel, aluminum and copper with time; however, chlorine water, modified EO water and deionized water produced minimal changes on these materials. Regardless of the treatment water used, the surface roughness of stainless steel and PVC essentially remained the same. Carbon steel, copper, aluminum and stainless steel had a fair, good, good and outstanding corrosion resistance in EO water, respectively. Chlorine and modified EO water had a much less corrosive effect than EO water on all the materials tested.

電解加工における各種加工液の加工特性について

In this report the machining characteristics of some electrolytes for carbon steel (S 15 C) and austenitic stainless steel (SUS 27) were experimentally investigated. The electrolytes were sodium chloride solution including sodium sulfite, sodium chloride solution including sodium hexametaphosphite and calcium chloride, sodium nitrite solution, potassium bromide solution, and sodium chlorate solution, which are less corrosive for mild steel than sodium chloride solution. The main results are as follows.(1) In the case of sodium chlorate solution the two materials can not be machined by single-phase half-wave current, but by square wave current. The surface finishes by the latter are slightly worse than those in sodium chloride solution, but the machined forms are rather sharper. The surface roughness is not affected by the pH value of the solution in the range from 6 to 11.(2) In the case of other electrolytes better surface roughnesses are obtained by square wave current than by single-phase half-wave rectified current. The surface roughness of carbon steel is not affected by the kind of electrolyte, and the surface roughnesses are within a range from 4 to 6 μ Hmax. The surface roughnesses of austenitic stainless steel are within a range from 1 to 2 μ Hmax in other electrolytes besides potassium bromide solution.