High-performance alloys

A distinction is often made between those alloys that are primarily used for high-temperature strength, commonly referred to as superalloys, and those that are primarily used for corrosion resistance. Hi -performance alloys are defined, in the present context, as Ni-, Ni-Fe-, and Co-base alloys able to operate at high temperatures, 550°C, and pressmes. Fe, Co, and Ni are transition metals with consecutive positions in the periodic table. The relative order of abimdance decreases as Fe, Ni, Co. 

Ni- and Fe-Ni-base high-performance alloy properties are controlled by all three variables. However, the first variable is essen- 

Changes in room-temperature strength and ductility of cast Co-base high-performance alloys have been correlated with precipitation of 

Copper. Additions of copper provide improvement in the resistance of nickel to nonoxidizing acids. In particular, alloys containing 30 to 40% copper offer useful resistance to deaerated sulfuric acid and excellent resistance to all concentrations of deaerated hydrofluoric acid. Additions of 2 to 39% copper to nickel-chromium-molybdenum-iron alloys are also known to improve resistance to hydrochloric, sulfuric, and phosphoric acids.  

TABLE 8.22 Common Ranges of Main Alloying Additions and Their Effects in High-Performance Alloys 

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Thermal Properties. ABS is also used as a base polymer in high performance alloys. Most common are ABS—polycarbonate alloys which extend the property balance achievable with ABS to offer even higher impact strength and heat resistance (2). 

ASM International 1997a Handbook No. 1. Properties and Selection Irons, Steels and High Performance Alloys, 10th Edition. OH ASM International. 

The analysis of specific elements for which GDMS is particularly well suited compared to other methods (e.g., measurement to ppb levels of S, Se, Te, Pb, Bi, Tl, in high-performance alloys and measurement of U andTh in sputter targets)... 

Remarks on some commercial aluminium alloys. A1 metal and A1 alloys find several applications this is also reflected in the variety of treatments and processing techniques to which they may be subjected. A recent example may be the semi-solid processing (thixoforming) of high-performance alloys. 

Production of High-Performance Nickel Alloys. In the production of high-performance alloys, the critical first step of alloying requires sophisticated equipment, stringent controls, and expertise. Several production methods are used. 

Start Properties and Selection Iron, Steels, and High-Performance Alloys, ASM International, Materials Park, OH, 1990. 

Special Metals Corporation. In High-Performance Alloys for Resistance to Aqueous Corrosion Special Metals Corporation New Hartford, NY, 2000. 

Fig. 7.22 Correlation between the critical pitting temperature and critical pitting potential of 1 7 high-performance alloys. The alloys are ...

P.E. Manning, Comparison of Several Accelerated Laboratory Tests for the Determination of Localized Corrosion Resistance of High-Performance Alloys, Corrosion, Vol 39, 1983, p 98-102... 

Muzyka, D. R. and Klarstrom, D. L.. Innovations in high performance alloys and their applications to the process industries. In Proceedings of the Conference on Advances in Materials Technology for Process Irubistry Needs, Atlanta, 1984, NACE, Houston, pp. 89-103 (1985)... 

Superalloys are much more costly than tool steels, but these grades are applicable when a significantly longer knife life is desired. These high-performance alloys are not as susceptible to thermal cracking and maintain their strength at elevated temperatures, therefore knife cooling is not as critical compared to hot work tool steels. 

These were blended in 1 1 ratio to result in high-performing alloys ... 

Polypropylene, PP, was compatibilized with polyethylene, PE, by grafting PP with a basic monomer and PE with an acidic monomer, then blending the modified polymers. Thus, PP was modified with drmethylamino ethyl methacrylate while PE with methacrylic acid. These were blended in 1 1 ratio to result in high-performing alloys... 

Geon HTX Poly(vinyl chloride)-based high performance alloy BF Goodrich/Geon... 

Kirchner, R. W., Crook, P., and Asphahani, A. I., Wear/Corrosion-Resistant, High Performance Alloys for the Food Industries, Paper 102, CORROSION 84, NACE, 1984. 

Besides pressure rating, the durability and reliability need to match the intended use. It goes without saying that a vessel made of high-performance alloys needs to be equipped with sensors of the same or better grade material. Additional wear resistance is realizable with additional coating of the tip, for example, carbide-coated tips for use in low-density polyethylene (LDPE) plants. 

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