Thermal Processing

 

Since 1953, Rolled Alloys has been providing specialty alloys to the thermal process industry. Including our proprietary alloy RA330, our comprehensive inventory includes a diverse mix of heat resisting alloys that provide both excellent strength and oxidation resistance for equipment that operates in the 1000-2100°F range.

Heat Treating

Hot coilOur thermal processing alloys are used for bar frame baskets, corrugated shrouds, and other fixtures that carry the parts to be heat treated into and out of the furnace. Inside the furnaces, our alloys are used for radiant tubes, fans, muffles, inner covers, belts, etc. RA330 is a workhorse alloy due to its good strength, its resistance to carburization, and its resistance to thermal fatigue after repeated temperature cycling. RA330 is also immune to sigma phase formation so it maintains its ductility allowing for restraightening and/or repair welding to extend the useful life of a fixture. Our alloys are commonly used in a variety of heat treating operations including annealing, vacuum treating, neutral hardening, carburizing, molten salts, and various other applications.

Steel & Aluminum Mills Our materials are used for equipment such as radiant tubes, inner covers, argon oxygen decarburization (AOD) hoods and chutes, furnace rollers, heat shields, coal injection lances, burners, and recuperators. Often these applications use alloys such as 309, 310, or 601 but when superior strength is required, RA 253 MA or RA 602 CA.
Powder Metals Rolled SteelThermal processing alloys are used in both the production of iron powders and finished sintered parts. RA 253 MA and RA330 are used for sheet belts and muffles for the annealing of iron powders. Most sintering muffles are commonly constructed from alloys RA330 or 601. RA333, RA 602 CA and 601 are also commonly used for furnace muffles and boats for the reduction of molybdenum and tungsten powders.
Power Plants Coal fired power plants require alloys that not only have good strength and oxidation resistance at temperature, but also ones that can tolerate hot corrosion in the form of sulfidation and possibly abrasion. For most applications lower nickel alloys are used because of their ability to tolerate sulfur better than nickel based alloys. Alloys such as 309, 310, and RA 253 MA are commonly utilized for components such as coal nozzles, burners, tube shields, tube supports, cyclone dip tubes, and soot blowers.
Chemical & Refining Red CoilRefineries use thermal processing alloys in the heating of the crude oil prior to distillation. Materials such as 310 stainless are commonly used in the crude heaters for burners while heavy plate in 310, RA 253 MA, and RA330 are commonly used for tube supports and hangers. Thermal processing alloys are also used to fabricate flare tips which oxidize and destroy any off-gases from the refinery.

Alloys such as 800H/AT, are used in methane reformer furnaces for tubes, pigtails, outlet headers, bypass ducts, etc. Where temperatures and the carburizing conditions are such that metal dusting is a concern alloys such as RA 602 CA and RA333 are commonly considered. In the manufacture of nitric acid, thermal processing alloys are used for catalyst support grids and baskets.
Calciners & Rotary Dryers Rotary DryerAlumina and kaolin clay, along with other powdered pigments and catalysts, commonly require thermal treatment to perform oxidation, and modify surface properties. Indirect fired kilns contain rotating drums often referred to as a calciner or rotary retort, to transport and stir the powders while they are processed in the furnace. The shell and flights of these drums require thermal processing alloys. Resistance to deformation and also minimal scaling are important. Flaking of the surface scale from the calciner shell can be a source of contamination. RA 602 CA is commonly used for critical applications, like high purity alumina, that cannot tolerate contamination.
Thermal Oxidizers Units used to thermally destroy harmful VOCs operate at elevated temperatures. In regenerative thermal oxidizers, thermal processing alloys are used for dampers to control the hot gas flow in and out of the combustion chamber. They are also used for the cans or walls that contain the ceramic heat exchange media. Recuperative thermal oxidizers are similar in appearance to shell and tube heat exchangers. In these designs thermal processing alloys are used for the tubes, shells, baffles, and tube sheets.