INCOLOY® alloy 803 (UNS S35045), an iron-nickelchromium alloy, is designed for use in petrochemical, chemical and thermal processing applications. The nickel and chromium contents of alloy 803 are higher than those of INCOLOY alloys 800H and 800HT®. The ratios of nickel, iron and chromium are balanced to provide optimum properties in the temperature range of 1550°F (840°C) to 2100°F (1150°C). Alloy 803 is a cost-effective material which provides an exceptional level of high-temperature corrosion resistance in oxidation, sulfidation and carburization environments. INCOLOY alloy 803 exhibits excellent stress-rupture strengths at elevated temperatures. These characteristics, along with a high resistance to carburization and cyclic oxidation, make INCOLOY alloy 803 the material of choice for many severe applications including ID-finned pyrolysis tubing in high-severity ethylene furnaces. INCOLOY alloy 803 is produced in all major product forms in a wide variety of sizes, finishes and tempers. One unique product form is internally finned, either straight or spiralled fins, cold finished tubing. Strict process controls ensure complete material traceability and structure consistency throughout the manufacture of all INCOLOY alloy 803 products. Table 1 - Limiting Chemical Composition, % Nickel ..........................................................................32.0-37.0 Chromium....................................................................25.0-29.0 Iron ...............................................................................Balance* Carbon ........................................................................0.06-0.10 Aluminum ....................................................................0.15-0.60 Titanium.......................................................................0.15-0.60 Copper........................................................................0.75 max. Sulfur ........................................................................0.015 max. Manganese ...................................................................1.5 max. Silicon ...........................................................................1.0 max. *Reference to the “balance” of an alloy’s composition does not guarantee this is exclusively of the element mentioned, but that it predominates and others are present in minimal quantities.