• Journal of Surface Science and Engineering
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• v.25 no.5
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• pp.263-269
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• 1992

To enhancing efficiency of hard chrome plating solution more highly, cathode current efficiency were surveyed connected with hardness of deposits, surface morphology, TEM analysis and corrosion test of anode materials. Efficiency war increased up to 26% values by adding catalyst and two kind of additives. With given bath composition and 6$0^{\circ}C$, 60A/d$\m^2$ electrolosis conditionss bright and micro cracked deposits were well obtained, which showed HV 1000 values. From corrosion tests, anode materials such as Pb-Te (0.02%) and Pb-Ag(1%) showed most anti-corrosive results. Through SEM micrograph observations, ef-fects of additives on levelling, brightness and micro crack properties of hard chrome deposits could be con-firmed. Also, through TEM analysis the fact that deposits from crack free solution or high speed solution were more fine than from sargent solution could be confirmed.

• Journal of Surface Science and Engineering
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• v.34 no.4
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• pp.281-288
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• 2001

Phosphating treatments have been performed to improve paint adhesion and corrosion resistance of zinc and zinc alloy coated steels for a long time. In this work, the effects of the addition of chelate compound were studied to improve the stability of surface conditioning solution and properties of zinc phosphate films. The coalescence of colloidal Ti-compound and extraneous charged particles (alkaliearth metal cation such as $Mg^{2+}$ , $Ca^{2+}$ ) were suppressed by using a surface conditioning solution with chelate compound. Therefore, after surface conditioning solution containing chelate compound was left standing for one week at room temperature, the formation of a white sediment was decreased comparing to surface conditioning solution without chelate compound. The crystal size of phosphate film was fine and the whiteness value of phosphated zinc coated steel sheets was also high without the decrease of corrosion resistance and anti-patina. It was very effective to use chelate compound improving the stability of surface conditioning solution.

• Applied Chemistry for Engineering
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• v.17 no.5
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• pp.498-503
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• 2006

i-(2',5'-Diketotetrahydrofuranyl)octadecenyl acid (OSA), an intermediate for the lubricating oil additive, was prepared by the ene-reaction of oleic acid with maleic anhydride. The reaction progress was monitored by gas chromatography by analyzing the amount of OSA. The series of succinimidyl compounds were synthesized by the reaction of alkyl amines and OSA. As a kind of lubricant additives, demulsibility, anti-wear, and anti-corrosion properties of these succinimidyl compounds were measured. The derivative of octadecylamine which has relatively long-chained alkyl group has showed good properties.

• Journal of the Korea Institute of Building Construction
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• v.14 no.6
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• pp.505-513
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• 2014

The purpose of this study is to evaluate the corrosion protective properties of a Zn-Sn metal spray method according to the contents of Zn and Sn by a CASS test and the electrochemical theory. In the experiment, the CASS test and the electrochemical test were conducted to investigate the corrosion protective property of the Zn-Sn Metal Spray system, the Zinc galvanizing system, and the heavy duty coating system. As a result, it was confirmed that the Zn-Sn (65:35) Metal Spray system had very high corrosion protective property through the electrochemical characteristic as comparison with the other anti-corrosion systems and was very effective to prevent steel products from corrosion.

• Journal of Surface Science and Engineering
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• v.46 no.4
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• pp.168-174
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• 2013

In this study, low-cost, high-speed deposition, excellent processability, high mechanical strength and electrical conductivity, chemical stability and corrosion resistance of stainless steel to meet the obsessive-compulsive (0.1 mm or less) were selected CrN thin film. new price reduction to sputter deposition causes - the possibility of sublimation source for inductively coupled plasma Cr rods were attempts by DC bias. 0.6 Pa Ar inductively coupled plasmas of 2.4 MHz, 500 W, keeping Cr Rod DC bias power 30 W (900 V, 0.02 A) is applied, $N_2$ flow rate of 0.5, 1.0, 1.5 sccm by varying the characteristics of were analyzed. $N_2$ flow rate increases, decreases and $Cr_2N$, CrN was found to increase. In addition to corrosion resistance and contact resistance, corrosion resistance, electrical conductivity was evaluated. corrosion current density than $N_2$ 0 sccm was sure to rise in all, $N_2$ 1 sccm at $4.390{\times}10^{-7}$ (at 0.6 V) $A{\cdot}cm^{-2}$, respectively. electrical conductivity process results when $N_2$ 1 sccm 28.8 $m{\Omega}/cm^2$ with the lowest value of the contact resistance was confirmed that came out. The OES (SQ-2000) and QMS (CPM-300) using a reactive deposition process to add $N_2$ to maintain a uniform deposition rate was confirmed that.

• Corrosion Science and Technology
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• v.7 no.5
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• pp.265-268
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• 2008

Prestressed Concrete Cylinder Pipe(PCCP) had became one of the dominating kinds of pipes substituting for steel pipes because of its unique feature (high intensity, high pressure and high leakproofness). PCCP was produced firstly by Bonna company in France. By the end of 20th century, there were over 19000 km of this product installed in America. PCCP was introduced from Ameron company by Shandong Eletric Power Pipeline Engineering Company in 1988. As the statistical data in 2002, 700 km of PCCP had been applied in China, and the application trended towards rapid increase.Since prestressing wire would be corroded in environment, Several accidents due to the breakdown of pipe had happened. Consequently the external wall of pipe should be covered with protective coatings. There was a lack of technical study in corrosion and control of PCCP, because PCCP had been applied for a short time in China. in order to ensure the service life of PCCP, we have developed a kind of protective coating for concrete pipe, which had high intensity and anti-corrosive property with convenient applicability. The physical and chemical properties, painting technology and field application of this coating was introduced in the paper, at the same time, the future of external protective coating for PCCP was looked into.

• Korean Journal of Materials Research
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• v.16 no.7
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• pp.430-434
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• 2006

Au/Ni coatings are widely used in the electrical interconnect system, such as connectors, sockets and wire crimps. But due to repeated mechanical contacts, fretting corrosion occurs and causes a rapid increase in resistance. As an attempt to resolve these problem, application of Ni-P-PTFE to replace Ni undercoats was proposed, for which basic materials properties of Ni-P-PTFE coatings for preventing fretting corrosion was examined in this study. The Ni-P-PTFE coatings were formed by electroless Ni plating and PTFE coating followed by the heat-treatment. PTFE particles were found to be uniformly distributed in the Ni-P matrix. The Ni-P-PTFE coatings showed the excellent anti-adherent property with the contact angle of $104.3^{\circ}$, microhardness of 144.3 Hv comparable to that of Ni-P, and electric conductivity equivalent to that of Ni-P.

• Korean Journal of Materials Research
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• v.21 no.1
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• pp.8-14
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• 2011

To improve the chemical stability of metal, the ceramic coatings on metallic materials have attracted interest from many researchers due to the chemical inertness of ceramic materials. To endure strong acids, SiOC coating on metal substrate was carried out by dip coating method using 20wt% polyphenylcarbosilane solution; SiC powder was added to the solution at 10wt% and 15wt% to improve the mechanical properties and to prevent cracks of the film. Thermal oxidation as a curing step was carried out at $200^{\circ}C$ for crosslinking of the polyphenylcarbosilane, and the coating samples were pyrolysized at $800^{\circ}C$ under argon to convert the polyphenylcarbosilane to SiOC film. The thicknesses of the SiOC coating films were $2.36{\mu}m$ and $3.16{\mu}m$. The quantities of each element were measured as $SiO_{1.07}C_{6.33}$ by EPMA, and it can be confirmed that the SiOC film from polyphenylcarbosilane was formed in a manner that was carbon rich. The hardness of the SiOC film was found to be 3.2Gpa through nanoindentor measurement. No defect including cracks appeared in the SiOC film. The weight loss of the SiOC coated stainless steel was within 2% after soaking in 10% HCl solution at $80^{\circ}C$ for one week. From these results, SiOC coating shows good potential for application to protect against severe chemical corrosion of stainless steel.

• Journal of the Korean Applied Science and Technology
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• v.20 no.4
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• pp.372-376
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• 2003

Water-soluble cutting fluids are used for processing of aluminium materials. This short article describes properties of new additives of water-soluble cutting fluids for aluminium materials. Various Diels-Alder adducts of unsaturated fatty acids with acrylic acid of maleic anhydride were prepared by thermal reactions. Triethanolamine salts of Diels-Alder adducts of dehydrated castor oil fatty acids with acrylic acid or maleic anhydride showed excellent anti-corrosion property of aluminium materals. These thermal adducts showed anti-rust property for cast-iron chips, too.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.1093-1097
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• 1996

The Substitution development of 7075-T6 Al alloy to 7050-T74 Al alloy in small arms to improve anti-stress corrosion cracking was processed along with mass productivity consideration. To meet 7050 Al alloy material characteristics Indirect extrusion type was adopted and local heating above recrystalization temperature in forging process had to be avoided. The T74 aging treatment was 12$0^{\circ}C$ -6hrs and 175$^{\circ}C$ -12hrs and was appropriate for both machanical and anti-cohesion properties. In accessment of field application test 7050Al alloy made parts of small arms showed equivalent or better performance than 7075 Al alloy.