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The composition and corrosion behaviors of recycled and virgin Pb anode were investigated in industrial zinc electrowinning solution with different methods. The purpose of this study is the illustration of good anticorrosion activity of virgin Pb anodes compared to recycled one in industrial operation, while the compositions of both of them are the same which obtained from quantmetry method.

Its corrosion properties and electrocatalytic activity toward oxygen evolution reaction were appraised using potentiodynamic polarization, electrochemical impedance spectroscopy, galvanostatic polarization and ionic equilibrium methods. In addition, composition of anodes investigated with X-ray photoelectron spectroscopy (XPS) method. The surface composition of samples was studied via X-ray diffractogram (XRD).

The results indicate that the anodes display different anodic behaviors during the galvanostatic polarization. Virgin Pb anode shows a “potential reduction” about 320 mV lower than recycled Pb anode after 6 h of polarization; also, the stable potential after 72 h for virgin Pb anode is 100 mV lower than recycled Pb anode. Also, The XPS results show a trace amount of Cl in recycled anodes which cause the more corrosion activity. XRD results indicate that virgin Pb anodes have been covered by more oxides than recycled anodes after 72 h of electrowinning.

The treatment of corrosion behavior by virginity has not been detected by any researchers yet. Therefore, it is imperative to study the corrosion behavior and exact composition analysis of virgin and recycled Pb anodes to comprehension of them. This paper fulfills this need.

The purpose of the paper is to study effect of the implantation of oxygen and helium ions on the corrosion performance of the AISI3l6L stainless steel. It presents useful new results which allows one to draw conclusions as to the suitability of the helium and oxygen ion implanted AISI 316L stainless steel for biomedical use in the body.

The implantation of oxygen and helium ions was done on AISI 316L SS at an energy level of 100 keV at a dose of 1×10¹⁷ ions/cm², at room temperature. In order to simulate the natural tissue environment, an electrochemical test using cyclic polarization was done in a 0.9 percent sodium chloride solution at a pH value of 6.3 at 37°C. This was carried out on both the virgin and implanted AISI 316L stainless steel for the purpose of comparing performance. In addition to this, the hardness of the virgin and implanted samples was also studied using Vickers microhardness tester with varying loads. Besides, the surface morphologies of the implanted samples and the corroded samples were studied with XRD and SEM.

From the study the following findings are made. First, the XRD and SEM results were found to be in accordance with the corrosion test results. Second, the general corrosion behavior showed a significant improvement in the case of both helium implanted (icorr=0.0689 mA/cm²) and oxygen implanted (icorr=1.104 mA/cm²), when compared to the virgin AISI 316L SS (icorr=1.2187 mA/cm²). The pitting corrosion showed a significant improvement for helium implanted (Epit=230 mV) when compared to virgin material (Epit=92 mV). The oxygen implanted has not shown any improvement (Epit=92 mV). The surface hardness is found to be 1202 HV for helium implanted and 1020 HV for oxygen implanted, while it is found to be 195 HV for the virgin material. The hardness of the helium and oxygen implanted samples is found to be increased by about 600 percent and 500 percent, respectively, when compared to the virgin samples. Helium implanted samples show better performance in terms of corrosion resistance and hardness when compared to those of the oxygen implanted samples.

Although a number of authors have conducted many research on AISI 316L stainless steel, this work has original experimental results in terms of the oxygen and helium ion implantation parameters used and the specific tests: microhardness, electrochemical corrosion test, SEM and XRD that were used. It thus presents useful new results which allows one to draw conclusions as to the suitability of the Helium and Oxygen ion implanted AISI 316L stainless steel for biomedical use.

TRIUMPH AT OLYMPIA. In taking the Corrosion and Metal Finishing Exhibition from a small exhibition hall to Olympia we took a calculated risk. Could a specialist show of this kind justify its appearance at the national exhibition centre? Would the exhibitors get a proper return for the time, trouble and expense of participating in an Olympia show? Would the technical meetings and film shows attract audiences appropriate to the efforts of the Organisers?

Recently, the method of applying Dox‐Anode zinc silicate to a preheated surface has been advanced and a new system for applying zinc to metal, rendering the surface phosphated and primed, is now available. This system eliminates the usual phosphating operation with, it is claimed, better results. This hot‐spray system requires no de‐rusting, the adherent rust forming a key to receive the zinc silicate coating.

Electroplating bright antimony. A bath additive of sodium, ammonium or ferrous fluoborate may be used as a brightener for antimony electro‐deposition. Aqueous boric acid or soluble fluoboric salts can be used with anode corrosion promoters such as dibasic ammonium citrate or sodium tartrate. The coatings are attractive as well as corrosion resistant, and can be used as undercoats for nickel or chromium and as overcoats for lead indium alloys.—Brit. Pat. 736,832, General Motors Corporation, Detroit.

High‐Production ‘Vacu‐Blast’. A new form of gun has been introduced by the manufacturers of Vacu‐Blast, specially designed to obtain an extremely high rate of millscale removal from flat plate prior to fabrication. Indeed, the manufacturers claim that millscale can be removed with the gun at a rate varying between 300 and 600 sq.ft. /hr., according to the surface to be cleaned.

In this work, commercial silver metal contacts welded on top of silver plated brass or brass substrates have been exposed to air rich in NaCl. Scanning electron microscopy and energy dispersive analysis of the exposed contact surfaces were performed to identify the corrosion by‐products on top of the silver contacts, suspending wafers, and welding materials. Surface corrosion products were mainly found to consist of small spherules of Cu‐Zn or Ag‐Cu compounds which cover the surface of the contact proper with low adhesion properties. They mainly originate from the underplating wafer or welding materials. Electrical characterization of the contacting materials was based on dc temperature overheat tests, current switching cycle tests, and energy storage during ac current excitation. The experimental results display that the operating environment is indeed a very significant parameter determining the overall performance of the electrical contacts. New design rules as well as material selection properties may have to be systematically considered to allow for electrochemical induced degradation in saline operating environments.

FRANCE. Internal corrosion in pipes. Mild‐steel pipes as used in town gas distribution networks are corroded by the mixture of water vapour, carbon dioxide and oxygen. Corrosion occurs only if changes in temperature will cause condensation. The condensate forming on the metal is a heavily corroding agent. Once formed, the corrosion products will act as protective layers in certain circumstances.—(J. Morlet and G. Geoffray, paper read at the 74th Congress of the Association Technique de l'Industrie du Gaz en France, June 1957.)