• Corrosion Science and Technology
• /
• v.2 no.5
• /
• pp.233-237
• /
• 2003

Pickling inhibitors can be used to form an adsorbed layer on the metal surface to hinder the discharge of H^+$ and dissolution of metal ions. Nitrogen-containing inhibitors were selected as corrosion inhibitors for mild steel (MS) in pickling acid process. In this study, the addition of inhibitor, the pickling temperatures and the pickling times were the parameters to investigate the effects on the inhibition efficiency (IE) for MS by using weight loss measurement. Preliminary results show that the IE increased with the increase in pickling time from 10 minutes to 60 minutes, and the IE also increased with the increase in temperature at room temperature and $40^{\circ}C$. At the higher temperature. the IE values are higher and almost independent with the pickling time. Furthermore, the potentiodynamic polarization, open circuit corrosion potential-time and corrosion current-time studies show that nitorgen-containing inhibitor behaves predominantly as cathodic polarization. The roughness test and SEM investigation are also studied in this paper.

• Clean Technology
• /
• v.11 no.1
• /
• pp.21-28
• /
• 2005

Nitric acid free pickling solution was applied to solve the severe environmental problems attributed to nitric acid during pickling process of stainless steel product. In points of pickling capability and erosion of stainless steel base metal, a solution contains I% of hydrochloric acid and 2% of hydrofluoric acid and hydrogen peroxide was revealed as the best alternative to conventional mixed acid of nitric acid and hydrofluoric acid. To keep the pickling capability, it was necessary to maintain the concentration ratio of hydrogen peroxide to hydrochloric acid above 0.5.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.08a
• /
• pp.109-118
• /
• 2004

No.2 PCM (Pickling and tandem cold rolling mill) at Pohang works was revamped in 2003. The purpose of this project is to produce carbon and stainless steel using conventional carbon production process, rolling and annealing. This paper introduces the applied facilities and technologies of PCM which are used in production of carbon and stainless steel. To realize the main purpose of this project, POSCO have developed laser weld technology in normal carbon and special steel (stainless, high carbon and high silicon). And this report describes the method which is developed to get down the surface defect of stainless 400 series. After revamping, No.2 PCM can have competitive power in this field and can supply the special steel using carbon rolling process.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.65.3-65
• /
• 2001

In order to apply for pickling line in cold rolling process, a high power magnetostrictive ultrasonic transducer was developed. The transducer is expected to overcome the shortcomings of conventional high power ultrasonic transducers. The transducer consists of Fe-Co-V alloy sheets for the magnetostrictive material, an ultrasonic horn made of Hastelloy to withstand acid solution, and electric driving circuit. In the development, the transducer was designed with the theoretical and numerical methods such as finite element method, and was characterized with experimental water tanks. The developed transducers turned out to be able to generate the sound pressure up to 20,000 Pa, and to be suitable for application ...

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.12
• /
• pp.1173-1177
• /
• 2015

This paper deals with estimating the acid concentration of pickling process using the Volterra inputs. To estimate the acid concentration, the whole pickling process is represented by the grey box model consists of the white box dealing with known system and the black box dealing with unknown system. Because there is a possibility of nonlinear term in the unknown system, the Volterra series are used to estimate the acid concentration. For the white box modeling, the acid tank solution level and concentration equations are used, and for the black box modeling, the acid concentration is estimated using the Volterra Least Mean Squares (LMS) algorithm and Least Squares (LS) algorithm. The LMS algorithm has the advantage of the simple structure and the low computation, and the LS algorithm has the advantage of lowest error. The simulation results compared to the measured data are included.

• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.144-148
• /
• 2001

In this study, to improve the color of iron oxide from waste pickling acid at the cold rolling mill, quality control technologies to improve color were investigated. During operation of the spray roaster, the charge amount of waste acid per hour, temperature, and numbers of spray nozzles were investigated. At the admixing process, titanium oxide, silica, and goethite were tested. The color character of iron oxide can be improved by process control of the spray roaster and the admixing process at a pigment factory. Iron oxide from this study is appropriate for use as a colorant of a concrete product.

• Corrosion Science and Technology
• /
• v.23 no.5
• /
• pp.374-382
• /
• 2024

Recently, Fives Stein has developed a non-oxidizing wet cooling process dedicated to high strength steel quenching in continuous galvanizing lines to freeze desired bainite and martensite phases, triggering Tata Steel R&D to collaborate in an innovative project together with Fives Stein. They have demonstrated that this promising technology could improve metallurgy and coatability. This technology can be implemented for galvanizing 3rd generation Advanced High Strength Steel (AHSS) / Ultra High Strength Steel (UHSS) grades of Tata Steel. The pickling effect of wet cooling agent (water containing an acid) on steel surface after annealing prior to dipping into the Zn bath according to the wet cooling concept developed by Fives Stein was assessed by a metallurgy driven set of experiments on a Non-Oxidizing-Water-Quench (NOWQ) cooling test bench simulation. Selected samples were further preheated to required temperature in 5%H₂/N₂ and subsequently dipped in liquid zinc by a hot dip zinc simulator HDAS (Heat to Coat heated, i.e., without annealing). Results of experiments along with X-ray Photoelectron Spectroscopy (XPS)/Glow Discharge Optical Emission Spectroscopy (GDOES) analyses demonstrated that the NOWQ technology significantly improved pickling efficiency of Mn, Si, and Al selective oxides to secure good Zn wetting of exposed metallic strip surface.

• Clean Technology
• /
• v.3 no.2
• /
• pp.25-27
• /
• 1997

• 한국전기화학회:학술대회논문집
• /
• 2001.10a
• /
• pp.21-21
• /
• 2001

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2003.05a
• /
• pp.37-37
• /
• 2003