Lead and its Alloys

Lead is soft and malleable, and possesses an excellent resistance to corrosion. It has been used for water pipework and waste disposal systems, but nowadays is replaced by other materials. A major application for lead is in the manufacture of lead-acid storage batteries which account for almost 30% of the annual world consumption of lead. Cable sheathing, soft solders, and fusible plugs in the sprinklers of fire-fighting systems are other applications of lead alloys (see Table 4.14). 

Pure nickel possesses an excellent resistance to corrosion by alkalis and many acids, and consequently, is used in chemical engineering plant. For cheapness, nickel is frequently used as a cladding of thin sheet on a mild steel base. Nickel may also be electroplated on a number of materials, and an intermediate layer of electrodeposited nickel is essential in the production of chromium-plated mild steel. 

The principal nickel-based alloys used industrially are Monel, Inconel, Incoloy, and the Nimonic series of alloys. Table 4.15 gives the composition and uses of some nickel alloys. 

The useful properties of titanium are its relatively high strength, coupled with a low density, and its excellent corrosion resistance. However it does possess some characteristics that make processing both difficult and costly. The main uses of titanium alloys are where excellent corrosion resistance is required. 

---

Lead and its alloys are generally melted, handled, and refined in cast-iron, cast-steel, welded-steel, or spun-steel melting ketdes without fear of contamination by iron (qv). Normal melting procedures require no dux cover for lead. Special reactive metal alloys require special alloying elements, duxes, or covers to prevent dross formation and loss of the alloying elements. 

Heubner, U. and Reinert, M., Effect of Small Silver Contents on the Characteristics of Lead and its Alloys , Pb80, Seventh International Lead Conference, Lead Development Association, London... 

Cook, A. R. and Smith, R. Atmospheric Corrosion of Lead and Its Alloys , in Ailor, W. H. Almospheric Corrosion, Wiley Interscience, New York (1982)... 

Soldered joints present their own characteristic corrosion problems usually in the form of dissimilar metal attack often aided by inadequate flux removal after soldering. Such joints have always been a source of concern to the electrical industry. Lead-containing solders must be used with caution for some types of electrical connection since PbfOHjj.PbCOj may be found as a corrosion product and can interrupt current flow. Indium has been found to be a useful addition to Sn-Pb solders to improve their corrosion resistanceHowever, in view of the toxicity of lead and its alloys, the use of lead solders, particularly in contact with potable waters and foodstuff s, is likely to decline. 

Costa V, Urban F (2005) Lead and its alloys metallurgy, deterioration and conservation, Rev Conserv, International Institute of Conservation 6 48-62. 

The corrosion rates of lead and its alloys are low in seawater, as seen from the data in Table 4.58. 

Materials such as metals, alloys, steels and plastics form the theme of the fourth chapter. The behavior and use of cast irons, low alloy carbon steels and their application in atmospheric corrosion, fresh waters, seawater and soils are presented. This is followed by a discussion of stainless steels, martensitic steels and duplex steels and their behavior in various media. Aluminum and its alloys and their corrosion behavior in acids, fresh water, seawater, outdoor atmospheres and soils, copper and its alloys and their corrosion resistance in various media, nickel and its alloys and their corrosion behavior in various industrial environments, titanium and its alloys and their performance in various chemical environments, cobalt alloys and their applications, corrosion behavior of lead and its alloys, magnesium and its alloys together with their corrosion behavior, zinc and its alloys, along with their corrosion behavior, zirconium, its alloys and their corrosion behavior, tin and tin plate with their applications in atmospheric corrosion are discussed. The final part of the chapter concerns refractories and ceramics and polymeric materials and their application in various corrosive media. 

Trace elements can be separated from solutions of different metals by reducing a small amount of the matrix metal with sodium hydroborate (NaBH4) [82-85]. The metallic precipitate serves as a trace collector for all the elements that are electrochemically more noble than the matrix. The method has been used in the trace analysis of lead and its alloys [82-85]. 

The iodide method was used in determinations of bismuth in pharmaceuticals [66], sea water, A1 and Bi alloys [37], organic compounds [67], lead and its alloys [1,26], copper and its alloys [1,29,68], cast iron and steel [69], antimony [70], and sulphide concentrates [1]. After extraction of the iodide complex with various organic cations, Bi was determined in water and soil [32], pharmaceuticals [31], soil and ores [33], and copper alloys [31]. 

The cuprizone method was used for determining copper in plant materials [130], biological samples [12], lead and its alloys [131], aluminium and magnesium alloys [132], platinum alloys [133], cadmium sulphide [134], borate glass [135], and petroleum samples [136]. 

Other basic dyes have been used in the determination of thallium in soils [61], antimony and cadmium [27], lead and its alloys [29,31], zinc and its alloys [28], and tungsten [32]. 

The phenylfluorone method has been applied for determination of tin in biological materials [83], waters and in fruit juices [84,85], rocks, minerals and soils [86], cast iron and steel [11,15,22,24,87], non-ferrous metals [88], lead and its alloys [9], and zinc [16]... 

These advances have positively influenced not only the way to produce batteries but also the technique of recovering lead and its alloys from spent accumulators. Indeed, the Pb/Ca alloy is produced from soft high-purity Pb and, because of the great... 

Shapiro479 has reviewed the synthesis of tetraalkylleads from lead and its alloys. 

G. Baralis, I. Tangerini A study of some dynamic properties of lead and its alloys, Proc. 3rd Inti. Lead Conference, Venice, ed. by European Lead Development Committee and Lead Development Association (Pergamon, London 1968) 309-319... 

For protection of steel in an SO c atmosphere, lead and its alloys (5 to 10% tin) coatings are employed. Pitting will occur in the lead coating at the time of... 

Coatings of lead and its alloy (5-10% Sn) protect steel substrate especially in industrial areas having an SO,t atmosphere. At the time of initial exposure, pitting occurs on the lead surface, however, the pits are self healed and then the lead surface is protected by the formation of insoluble lead sulfate. Little protection is provided by these coatings when in contact with the soil. 

As mentioned before, soil is a physically, chemically, and biologically complex system. Factors that affect corrosion in soil, in addition to specific ions, are resistivity of soil, oxygen content, and acidity. Field measurements of soil resistivity are covered in ASTM G 57, Method for Field Measurement of Soil Resistivity Using the Wenner Four-Electrode Method, which is the most widely used test, and using the proper meter produces accurate and reproducible results. Conducting field measurements of soil pH is covered in ASTM G 51, Test Method for pH of SoU for Use in Corrosion Testing. The corrosion resistance of lead and its alloys depends mainly upon the presence of silicate, carbonate, and to a lesser extent sulfates, in contributing to the passive film formation. 

The only other metal which is used as an anode is lead and its alloy with 1% silver and 6-15% antimony. These are remarkably corrosion resistant in halide free solutions and are used mainly in the zinc and copper electrowinning industries. 

THE DETERMINATION OF OXYGEN IN LEAD AND ITS ALLOYS (PbCuTe, PbSnCd)... 

---