• Corrosion Science and Technology
• /
• v.18 no.1
• /
• pp.16-23
• /
• 2019

Steels for automotive fuel tank require unique properties such as corrosion resistance for fuel, welding for joining, forming for press, and painting for exterior. Recently, automakers have been requiring excellent seam weldable steels to enhance manufacturing productivity of fuel tank. Thus, POSCO developed a new type of functional steels coated with nano-composite thin layer on Zn-Ni plating steels. The nano-composite coating solution was prepared by mechanical fine dispersion of solutions consisting of polymeric resin and nano-composite materials in aqueous media. The composite solution was coated on the plating steel surface by using roll coater and cured through induction furnace. These new developed plating steels were evaluated for quality performances such as seam and spot weldability, press formability, and corrosion resistance. These new functional steels coated with nano-composite layer exhibited excellent seam weldability and press formability. Detailed discussion of coating solution and experimental results suggest that nano-sized composite dispersion as coating layer plays a key role in enhancing the quality performance.

• Journal of the Korean institute of surface engineering
• /
• v.35 no.1
• /
• pp.17-32
• /
• 2002

Electroplating methods by molten salts and non-aqueous melts were employed for aluminium coating on STS 316L stainless steel. After coated with Ni or non-coated surface on stainless steel, Al pulse plating was carried out in two different types of electrolytes at room temperature. The Al layer from $AlCl_3$-TMPAC melts could not obtain appreciable thickness for engineering application due to chemical reactions between deposits and moisture of air. However, The Al coating by pulse plating in the Ethylbenzene-Toluene-$AlBr_3$ systems was found to be solid coating layer with a few $\mu\textrm{m}$ scale. The conductivity of Ethylbenzene-Toluene-$AlBr_3$ electrolyte was as functions of time and agitation. By seven days exposure after mixing of the electrolyte, Al-deposited layer shows uniform and near by pore-free with high current density (higher than 30mA/$\textrm{cm}^2$). The roughness and imperfection of coating layer were decreased with a increasing agitation speed. It was found that the optimum condition for the Al pulse plating on the 316L stainless steel was a 400mA peak current, duty cycle, $t_{on}$ $t_{ off}$=3ms/1ms, and a current density of 30mA/$\textrm{cm}^2$.

• Transactions of Materials Processing
• /
• v.15 no.5 s.86
• /
• pp.366-372
• /
• 2006

The effect of coating time in arc ion plating on surface properties of the TiN-coated high speed steel(SKH51) is presented in this paper. Surface roughness, micro-hardness, coated thickness, atomic distribution of TiN and adhesion strength are measured for various coating times. It has been shown that the coating time has a deep influence on the micro-hardness, the coated thickness, the atomic distribution of Ti and the adhesion strength of the SKH51 steels but that it has little influence on the surface roughness.

• Journal of the Korean institute of surface engineering
• /
• v.28 no.1
• /
• pp.23-33
• /
• 1995

AISI 304 stainless steel has high resistance to corrosion due to the presence of a self-healing chromium oxide film on the surface, which also accounts for the difficulty in plating. Surface cleaning of this alloy is of fundamental importance in gold plating since its effectiveness puts an upper limit on the quality of the final coating. The cleaning of AISI 304 stainless steel was investigated with elimination of artificial passive oxide film and degreasing of remaining buffing wax as stearic acid. The familiar cleaning methods i.e. ultrasonic cleaning, electro-cleaning and activation treatment were fabricated in this study. Activation treatment showed best cleaning efficiency for elimination of passive oxide film among these methods, which was also confirmed by AES (Auger electron spectrometer) analysis. However, the best condition of cleaning was obtained by combining these methods. Electrocleaning time, for degreasing the stearic acid layer, was decreased with increasing amount of added KCN.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2006.05a
• /
• pp.308-313
• /
• 2006

The effect of coating time on surface properties of the TiN-coated high speed steel(SKH51) by arc ion plating is and presented in this paper. Surface roughness, micro-hardness, coated thickness, atomic distribution of TiN and adhesion strength are measured for various coating times. It has been shown that the coating time has a deep influence more than 60 minites on the micro-hardness, coated thickness, atomic distribution of Ti and adhesion strength of the SKH51 steels, but that the coating time has little influence on the surface roughness.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.10 no.5
• /
• pp.44-50
• /
• 2011

The effect of deposition time in arc ion plating on surface properties of the TiN-coated SM45C steel is presented in this paper. The surface roughness, micro-particle, micro-hardness, coated thickness, atomic distribution of TiN, and adhesion strength are measured for various deposition times. It has been shown that the deposition time has a considerable effect on the micro-hardness, the coated thickness, and the atomic distribution of TiN of the SM45C steels but that it has little influence on the surface roughness and adhesion strength.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.2 s.179
• /
• pp.97-103
• /
• 2006

In this paper, effect of temperature in TiN-coating by arc ion plating on surface characteristics of a TiN coated high speed steel is investigated by experiments. Hardness, surface roughness, TiN-coating thickness and adsorption force are measured in order to evaluate the effects. For evaluation of the experimental data, one-way ANOVA method is used. It is concluded that the furnace temperature in the range $400^[\circ}C\~500^{\circ}C$ in AIP processing has a little influence on the TiN coating of the SKH51 steels.

• Journal of the Korean Ceramic Society
• /
• v.49 no.6
• /
• pp.505-510
• /
• 2012

A study of the recovery of tin and nickel from steel ball scraps for barrel plating was carried out through a physical treatment, a leaching treatment, hydrogen reduction and an electrolysis experiment. The recovery of the iron component was over 95% by the physical treatment. We obtained tin oxide in the form of metastannic acid ($SnO_2{\cdot}xH_2O$) with impurities of less than 5% from the leaching treatment. We also recovered the high-purity metallurgical tin at a rate that exceeded 99.9% by the electrolysis of crude tin obtained from the hydrogen reduction of metastannic acid.

• Journal of the Korean institute of surface engineering
• /
• v.15 no.3
• /
• pp.127-137
• /
• 1982

In chemical plating of nickel and chromium on steel, studies on various factors affect-ing the plating operations were carried out. The optimum bath compositions and operat-ing conditions were obtained. The structure and properties of the as deposits or deposits after heat treatment were investigated. (1) The most optimum conditions for the chemical nickel and chromium plating were; 〔Ni2+〕/〔H2PO2-〕; 0.5∼0.8, 〔Cr3+〕/〔H2PO2-〕; 0.6∼0.9 PH;5.0∼5.5, temperature; 90∼95$^{\circ}C$ (2) In the case of nickel deposition, the hardness of deposits increased with increasing phosphorous contents. Heat-treating at the temperature range 200$^{\circ}C$ to 600$^{\circ}C$, the maximum hardness of deposits was obtained at 400$^{\circ}C$ and decreased at temperature above 400$^{\circ}C$ due to growth of Ni3P. (3) Corrosion resistance of chemical nickel deposits was improved with increasing of p-hosphorous contents and heat treating temperature.

• Journal of the Korean institute of surface engineering
• /
• v.32 no.3
• /
• pp.224-234
• /
• 1999

An attempt was made to characterize the relationship between pretreatment processes, electrolysis conditions and behaviors of the plated gold layer. In order to investigate the effect of pretreatment processes on plating, rest potential measurements of various pretreated stainless steels and a.c.-impedance spectroscopy tests were carried out in the strike plating solution. Characteristics of plated gold layers and adhesions between plated gold layers and stainless steel substrates were examined by scratching tests and micro-Vickers hardness tests. The result shows that the strike plating enhanced the adhesion of interface, the cathodic electro-activation pretreatment process improving both corrosion resistance and adhesion strength. The preferred orientations of plated gold layers were examined by the X-ray diffraction technique. As the current density increases, [111] preferred orientation of plated gold layers was found to become well developed.