Boron in steel

Boron is used as an alloying element for steel. For that reason, the alloy ferroboron, with 20% boron, is manufactured in electrometallurgical processes and used as a raw material. Low boron contents, as low as 0.003% B, have a marked effect on the hard-enability of steels with medium high carbon contents. It leads to hardening through the component section without alloying the steel with expensive elements such as chromium and nickel. Boron steels of this type have been very much utihzed for agricultural machinery. 

The ability of steel to withstand moderate stress without plastic deformation and fracture at high temperature is its high-temperature strength. In steam turbines, hardened chromium steels with 9-12% Cr are used. If they are alloyed with some tenths of a percent of boron, small boride precipitations are formed in the iron matrix. These act as obstacles to dislocation movements (slips in the crystal grains) and by that means improve the high-temperature strength. 

Basic Geology and Chemistry of Borate, Ceramic Engineering and Science, 2001, 22, 61-75 Phyllis A. Lyday, Boron chapter in US Geological Survey Mineral Commodity Summaries 2002, 2002, pp. 36-37, and Boron chapter in US Geol cal Survey Minerals Yearbook 2001, Vol. I, Metals 

Discovery In 1825 H. C. Oersted in Copenhagen prepared the element aluminum for the first time. Between 1827 and 1845, Friedrich Wohler improved Oersted s process. In 1886 Charles M. Hall and Paul H roult independently developed the method for aluminum manufacture by electrolysis of fused salts, a technique now known as the Hall-H4roult process. The element s name has its own history. In 1761 de Morveau proposed the name alumina for the base in alum. The name aluminium was adopted by lUPAC to conform to the ium ending of most elements. Aluminum is the lUPAC spelling, and therefore the international standard. In 1925 the American Chemical Society decided to change the name to aluminum, still used in American literature and technical descriptions. 

Bauxite, named after Les Bauxde Provence, near Arles in southern France, is the most important ore. 

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Procedure (boron in steel). Dissolve about 3g of the steel (B content >0.02 per cent), accurately weighed, in 40 mL dilute sulphuric acid in a 150mL Vycor or silica flask fitted with a reflux condenser. Heat until dissolved. Filter through a quantitative filter paper into a 100 mL graduated flask. Wash with hot water, cool to room temperature, and dilute to the mark with water. This flask (A) contains the acid-soluble boron. 

Pasztor, L., J. D. Bode, and Q. Fernando Determination of Micro Quantities of Boron in Steel by a Solvent Extraction Method. Anal. Chem. 32, 277 (1960). 

Far more difficult, however, is the atomic absorption analysis of some other elements typically found in steel, for example Nb, As, Sb, Se, Te, or Bi. The determination of boron in steel in the range between 10 3 to 10 s weight percent has been practically impossible until recently. 

Typical examples of analytical applications of gas generation MECA detection include the determination of ammonium in fertiHzers, fluorine in toothpaste, boron in steel samples, and thiamine and cephalosporins in pharmaceutical preparations. 

The emission wavelength region below 200 nm has traditionally been called the vacuum ultraviolet (VUV). This region contains the best speetral lines for many industrially important elements, such as carbon, phosphorus, sulfur, and boron, in steel and cast iron by spark excitation, and the halogens for the inductively coupled plasma (ICP) analysis of oils and fuels. 

The importance of the trihalides as industrial chemicals stems partly from their use in preparing crystalline boron (p. 141) but mainly from their ability to catalyse a wide variety of organic reactions.BF3 is the most widely used but BCI3 is employed in special cases. Thus, BF3 is manufactured on the multikilotonne scale whereas the production of BCI3 (USA, 1990) was 250 tonnes and BBr3 was about 23 tonnes. BF3 is shipped in steel cylinders containing 2.7 or 28 kg at a pressure of 10-12 atm, or in tube trailers... 

Silicon s atomic structure makes it an extremely important semiconductor. Highly purified silicon, doped with such elements as boron, phosphorus, and arsenic, is the basic material used in computer chips, transistors, sUicon diodes, and various other electronic circuits and electrical-current switching devices. Silicon of lesser purity is used in metallurgy as a reducing agent and as an alloying element in steel, brass, and bronze. 

Main uses. Calcium is important in steel production. It has a strong ability to alter the oxides and sulphides. Treatment with calcium modifies the melting points of inclusions which rapidly float out of the steel. Calcium is important in one method of producing a neodymium-iron alloy which is a neodymium ferro boron raw material (through, for instance, the reaction Nd203 + Ca + Fe — NdFe + byproducts). 

Partly because of high mischmetal prices, substitution by boron alloys took most of the glitter out of the market for a decade. The Carpenter application is now a negligible fraction of the total consumption of mischmetal in steels. 

By heating mixtures of cobalt and boron in a current of hydrogen at 1100-1200° C., du Jassoneix 4 has prepared two borides of cobalt, namely, the Sub-boride, CoaB, and the Di-boride, CoB2. The former occurs as brilliant steel-grey needles of density 7-9 at 20° C. These are oxidised by moist air and readily dissolve in nitric acid. The di-boride represents the extreme limit of combination of boron with iron. Evidence of the existence of aMono-boride, CoB, has also been obtained.5... 

The large-production reinforcing agent used today is primarily glass. Other fibers include cotton, cellulosic fiber, sisal, polyamide, jute, carbon, graphite, boron, whiskers, steel, and other synthetic fibers.10 12> 289 291, 466 They all offer wide variations in composition, properties, fiber orientation/construction, weight, and cost (Tables 15.4 and 15.5... 

The fuel is transported from the reactor pools to Sellafield in MEBs contained within heavily shielded, high integrity, transport flasks. The MEBs are cylindrical stainless steel vessels containing stainless steel clad "Boral" or boronated stainless steel dividers between the fuel assemblies to prevent criticality. "Boral" consists of boron carbide particles in an aluminimn matrix clad with pure aluminimn and is widely used as a neutron absorber. MEB s are used to contain mobile contamination from crud or spalling smface layers of the fuel pins. 

Iron sub-boride or diferro bolide, Fe2B, is obtained by heating reduced iron and boron in a porcelain tube in an atmosphere of hydrogen.5 It occurs as steel-grey prisms, of density 7 37 at 18° C., and is attacked by dry air at dull red heat only, whilst moist air readily attacks it at ordinary temperatures. It dissolves in hot aqueous solutions of the mineral acids. 

Complex carbides containing boron, occurring frequently in boron-alloyed steels and superalloys, are also named carboborides. Metal borocarbides (see Table 1) are synthesized by powder metallurgical methods or are extracted from a metal matrix. There are pseudoternary or -quaternary borocarbides, such as Mn23(B, C) or (Cr, Mn, Fe)23 (B, C)g (t phases) although boron-carbon substitution in borocarbides is less pronounced than nitrogen-carbon substitution in metal carbonitrides. 

The worldwide consumption of boron compounds in 1996 was 1.24 - 10 t (as di-boron trioxide) predominantly (in the USA almost 80%) in the form of sodium borates (as raw ore concentrates, which are often used directly, or in purified or calcined form). The remainder comprises calcium or calcium sodium borates (colemanite, ulexite), which are also often directly utilized e.g. in the manufacture of E-glass fibers and in steel manufacture and other products such as boric acid and di-boron trioxide. 

A large difference was observed between the productions of the tartrolons in shaking flasks, with tartrolon B as the main product, or large-scale fermentation in steel fermenters with tartrolon B as the minor component. Table 9 shows a good correlation between the borate concentration in the medium and the production rate of tartrolon B. However, an increased boron supply by the addition of up to 0.5 g/L of sodium tetraborate showed no influence on the total amount of tartrolons formed. 

The curcumin method (in either the rosocyanin or rubrocurcumin version) has been applied for determining traee amounts of boron in biologieal materials [10], soils and plants [17], waters [51], silicon [52], chlorosilanes [20], uranium [1,53], zirconium and its alloys [53,54], nickel [55,56], copper alloys [56], cast iron and steel [12,57-59], beryllium and magnesium [53], and phosphates [2]. This method was also used for determining boric acid admixtures (about 0.05%) in powdered boron [11]. Some synthetic compounds having the structure similar to that of curcumin, were used in determining boron in water [60]. 

The Methylene Blue method has been utilized in determinations of boron in biological materials [33], soils and rocks [68], steels [32], silicon [7,69], copper and its alloys [34,35], and various chemical materials [70,71]. 

The method with azomethine H has been used for determining boron in plant materials [75], biological samples [76], plants [77], soils [77-79], water [80], sewage [4,81], rocks and bituminous [22,55,82], steel [47], copper, nickel, and cobalt alloys [9], boron nitride [83], and fertilisers [84]. Azomethine H has been utilized in automatic determination of boron [81] and in flow injection analysis (FIA) [75]. Boron has also been determined in plants and soils with the use of 4-methoxyazomethine H [85],... 

T. Yamane, Y. Kouzaka, M. Hirakawa, Continuous flow system for the determination of trace boron in iron and steel utilizing in-line preconcentration/ separation by Sephadex column coupled with fluorimetric detection, Talanta 55 (2001) 387. 

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