Scale removal copper alloys

Sodium-zinc alloys for phase diagram determination are prepared by melting the elements in glass tubes under H2- Samples of NaZujj are prepared by heating zinc for several hours above the melting point of NaZn,3 (557°C) with xs Na in alundum extraction thimbles with N2 or Ar in a steel bomb scaled with copper gaskets. Excess Na was removed by extraction with liq NHj. Both KZn,3 and KCd,2 were prepared in this manner. ... 

The most common acid solvent is inhibited muriatic acid. It is inhibited, as all acids solvents must be, to reduce chemical attack on metal surfaces to an acceptable level. Muriatic acid is cheap and effective. It forms reaction products that are generally water-soluble and so are removed in the used solvent. Sulfuric acid is seldom used because of its insoluble reaction products. Nitric acid cannot be prevented from attacking carbon steels or copper alloys. It has certain special applications where the substrate metal is stainless steel or aluminum. Of special interest for small-scale maintenance cleaning by plant personnel is sulfamic acid, mainly because it is a dry solid product that is safely to handle. It has acid properties only after it is dissolved in water. Solid inhibitors and wetting additives can be premixed into the packaged product. 

Svuface treatments discussed in this article include scale removal, polishing, btiffing, plating, conversion coatings, thermal spray, vapor deposition, and thermomechanical surface treatment. Titanium alloys generally do not reqvdre special surface treatments to improve corrosion resistance, because their resistance to many corrosive environments is excellent. However, titanium is coated or plated with corrosion-resistant metals (e.g., copper and platinum) as an alternative to oxide formation. 

Uses Cleaner for chem. cleaning of water systems removes scale, rust, grease, and oil while at same time passivating steel and cast iron surfaces penetrates existing deposits and removes them from metallic surfaces emulsifier for fatty components dispersant for insol. dirt particles Features High cone. protects steel, stainless steel, copper, copper alloys, aluminum, and chromium parts not affected by frost or heat Properties Yei. viscous Iiq. sp.gr. 1.44 0.02 g/cm (20 C) pH 1.3 0.2 (10%) UseLevei 10-20% cone. 

Chromium compounds are used in etching and bright-dipping of copper and its alloys. A typical composition for the removal of scale after heat-treating contains 30 g/L Na2Cr20y 2H2O and 240 mL/L concentrated H2SO4. It is used at 50—60°C. 

It is a metal surface treatment used to remove impurities, such as stains, inorganic contaminants, rust or scale from ferrous metals, copper and aluminum alloys. A solution called tarnision liquor, which contains strong acids, is used to remove the surface impurities. It is commonly used to descale or clean steel in various steelmaking processes. 

The molybdenum cleaning process is necessary to remove surface scale, general contamination, and any basis metal that may be present. Among the potential contaminants in wrought products, iron is of primary concern. Others, such as aluminum, carbon, cadmium, copper, and nickel, may also be present as elements, but they are more frequently present in the form of oxides. Removal of a controlled amount of basis metal may be desired to insure complete removal of contaminants. There are three main methods for cleaning molybdenum and molybdenum alloys. 

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