Applications Of C Alloys 241

TABLE 7.11 Major Industries Using Alloy C-276/C-4

I. Petroleum Petroleum refining Oils/greases Natural-gas processing

II. Petrochemical Plastic

Synthetic organic fibers Organic intermediates

Organic chemicals—chlorinated/fluorinated hydrocarbons Synthetic rubber

III. CPI—chemical process industries Fine chemicals

Inorganic chemicals



Fertilizer— agrichemicals—herbicides/pesticides


Industrial gases

IV. Pollution control FGD

Waste water treatment Incineration Hazardous waste Nuclear fuel reprocessing

V. Pulp and paper

VI. Marine/seawater

VII. Pharmaceuticals

VIII. Sour gas/oil and gas production

IX. Mining/metallurgical

As mentioned earlier, the original alloy C is now obsolete, except for use in some castings. In the last 35 years, approximately 60,000 tons of alloy C-276 and C-4 have been used in a variety of industries, some of which are listed in Table 7.11.

Due to its higher chromium content, Alloy C-22 did improve upon the weaknesses of alloy C-276 in highly oxidizing media. The introduction of alloy 59 in 1990 and the industry realizing the benefits of alloy C-276 over alloy C-22 in highly reducing environments, and availability of alloy C-276 from multiple sources as opposed to a single source for alloy C-22, led to a resurgence in alloy C-276 usage.

Today alloy C-22, an alloy of the eighties, has been superseded by alloys of the nineties, that is, alloy 59, alloy 686, and alloy C-2000. However, there has been no major industrial applications of either alloy C-2000 or alloy 686 to date. In contrast, alloy 59 with its first commercial introduction in 1990 has already found a wide number of applications, and these continue to increase as the "corrosion universe" realizes its superior corrosion resistance, excellent fabricability, weldability, and thermal stability behavior. This alloy is covered under all appropriate ASTM, AWS, and NACE MRO-175 specifications and is also covered in ASME Boiler and Pressure Vessel Code up to 1400°F and has a code case for SCIII applications to 427°C (800°F). This alloy is also covered in the various international specifications.

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