Metallurgy steel

Refractory brick -magnesium compounds m [MAGNESIUMCOMPOUNDS] (Vol 15) -use m ladle metallurgy [STEEL] (Vol 22)... 

Calcium is utilized in the manufacture of special metals such as zirconium, thorium, uranium and the rare earths, as a refining agent in metallurgy (steel, copper, magnesium, tantalum, lead) and in the manufacture of calcium hydride (hydrogen source). 

Mietz J, Schneider S, Oeters F (1991) Emulsification and mass transfer in ladle metallurgy. Steel Res 62 10... 

H.A. Ferguson, Heat Treating of Powder Metallurgy Steels, Heat Treating, Vol 4, ASM Handbook, ASM International, 1991, p 229-236... 

Rare-earth-modified powder metallurgy steel... 

Approximately 200 large enterprises are operating in ferrous and non-ferrous metallurgy, pipe and rolling industry. These include the world largest complexes for the production of cast iron, steel, rolled stock and pipes in Dniepropetrovsk, Zaporozhje, Donetsk, Makeevka, Mariupol and other cities. 

HBI is an effective trim coolant for molten steel in ladle metallurgy faciUties, ladle refiners, ladle furnaces, and vacuum degassers. It provides cold iron units in an ideal size and density for penetrating the ladle slag and cooling the metal. 

Metallurgy. The strong affinity for oxygen and sulfur makes the rare-earth metals useflil in metallurgy (qv). Mischmetal acts as a trap for these Group 16 (VIA) elements, which are usually detrimental to the properties of steel (qv) or cast iron (qv). Resistance to high temperature oxidation and thermomechanical properties of several metals and alloys are thus significantly improved by the addition of small amounts of mischmetal or its siUcide (16,17). 

B. R. Steele and D. Geldait, "Extraction and Refining of the Raiei Metals," Proceedings of the Symposium on the Institute ofMiningand Metallurgy,... 

Ladle metallurgy, the treatment of Hquid steel in the ladle, is a field in which several new processes, or new combinations of old processes, continue to be developed (19,20). The objectives often include one or more of the following on a given heat more efficient methods for alloy additions and control of final chemistry improved temperature and composition homogenisation inclusion flotation desulfurization and dephosphorization sulfide and oxide shape control and vacuum degassing, especially for hydrogen and carbon monoxide to make interstitial-free (IF) steels. Electric arcs are normally used to raise the temperature of the Hquid metal (ladle arc furnace). 

Proceedings from the Iron and Steel Society Vacuum Metallurgy Conference, Iron Steel Society, Warrendale, Pa., 1989 1992. 

W. C. Leshe, The Physical Metallurgy of Steels, McGraw-Hill Book Co., Inc., New York, 1981. 

IF Steel Sheet, Processing Fabrication and Properties, Canadian Institute of Mining, Metallurgy and Petroleum, Montreal, Quebec, Canada, 1991. 

Fig. 5. Micrographs of the microstructure of fully hardened and tempered tool steels produced by the powder metallurgy technique, showing uniform distribution and fine carbide particles in the matrix, (a) M-42 (see Table 6) and (b) cobalt-free AlSl T-15 having a higher concentration of fine carbide...

It maybe economical, therefore, to use these materials at or near the cutting edge instead of as the whole insert. The development of tools of TiC (40—55%) or TiN (30—60%) in a steel matrix on a steel core using powder metallurgy technology suggests a similar approach for cemented carbides as the need arises. 

Sihcon carbide is comparatively stable. The only violent reaction occurs when SiC is heated with a mixture of potassium dichromate and lead chromate. Chemical reactions do, however, take place between sihcon carbide and a variety of compounds at relatively high temperatures. Sodium sihcate attacks SiC above 1300°C, and SiC reacts with calcium and magnesium oxides above 1000°C and with copper oxide at 800°C to form the metal sihcide. Sihcon carbide decomposes in fused alkahes such as potassium chromate or sodium chromate and in fused borax or cryohte, and reacts with carbon dioxide, hydrogen, ak, and steam. Sihcon carbide, resistant to chlorine below 700°C, reacts to form carbon and sihcon tetrachloride at high temperature. SiC dissociates in molten kon and the sihcon reacts with oxides present in the melt, a reaction of use in the metallurgy of kon and steel (qv). The dense, self-bonded type of SiC has good resistance to aluminum up to about 800°C, to bismuth and zinc at 600°C, and to tin up to 400°C a new sihcon nitride-bonded type exhibits improved resistance to cryohte. 

The metallurgy of the cyclone equipment has in recent years focused primarily on type 304 H stainless steel. The 304 H material is durable and easy to fabricate and repair, withstands the high regenerator temperatures, and is oxidation- and corrosion-resistant. Essentially all internal surfaces of the cyclone that are subject to erosion are protected with a 2 cm layer of erosion-resistant lining. When installed and cured, most refractory linings are highly resistant to erosion. 

---