Traditional boiler-based power plants contain environments that are extremely challenging with regard to materials degradation.
These environments can include high wear seen in coal handling and crushing, high temperatures and corrosive gasses seen in combustion systems, corrosive condensates formed in the flue gas system, and corrosive water used in heat exchangers and pollution control.
With the widest range of materials in the industry, we have the products to fit virtually any application.
Boiler system environments are extremely challenging with regard to materials degradation.
The high temperatures and corrosive gasses seen in the combustion systems, along with the corrosive condensates formed as the gasses cool often require the most corrosion resistant grades that exist.
With the widest range of materials in the industry, ATI has a solution to fit virtually any application.
- Boiler Weld Overlay
- Pipe and Tube
- Heat Exchanger Tubing
Combustion in boiler systems can generate highly corrosive gasses that may contain halides, sulfur compounds, water vapor, carbon compounds, etc. Nickel alloys are often used to resist these environments often as weld overlay or cladding. Nickel alloys are also very resistant to the wet condensates found downstream of the boiler system and can be found in pipe and tube, ducting, dampers, and other components that are exposed to flue gas.
General corrosion resistance and resistance to chlorides are required properties of alloys used throughout a boiler fired plant. Stainless alloys are commonly used for piping and tubing in areas where heat and corrosion resistance are needed.
Alloys for Pollution Control
As a producer of the widest range of corrosion resistant alloys in the metals industry, ATI can meet virtually all of the requirements of the pollution control market. Many ATI alloys were developed specifically to resist the types of environments found in pollution control environments. From cost effective stainless alloys, to some of the most corrosion resistant nickel based alloys available, ATI is a complete source of specialty metals solutions for the pollution control industry.
- Absorber Towers
- Turning Vanes
- Slurry Piping
- Wet ESP Electrodes
- Service Water
- Heat Exchanger Tubing
The Flue Gas Desulphurization (FGD) environment often requires resistance to both chlorides and sulfuric acid. For the most severe conditions, such as wet FGD absorber inlet ducts, outlet ducts, chimney flues, damper seals, etc. Nickel alloys are often required. The most commonly used alloys are listed on the right.
Resistance to chlorides is a requisite property of alloys used in FGD applications. The level of chlorides will be dependent on many factors, including the chloride content of the coal being burned, the extent of water treatment and replacement (also referred to as the rate of "blowdowns"). Stainless steels are the alloys of choice for FGD absorbers. ATI offers a wide range of stainless steels to meet the specific requirements of each pollution control system.
ATI’s titanium and titanium alloys and titanium tubing products offer excellent corrosion resistance in a wide range of demanding process environments. Titanium is resistant to general corrosion, crevice corrosion, microbiologically influenced corrosion (MIC), erosion corrosion and galvanic corrosion. Applications in pollution control include chimney liners and FGD scrubber components.
Boiler Systems - Alloys for Balance of Plant
ATI has a wide range of alloys for balance of plant applications. ATI is a recognized leader in the development and supply of alloys for tubing for heat exchangers and condensers. As a producer of a wide range of corrosion resistant alloys, ATI can meet the requirements of virtually any tube or pipe environment. ATI supplies the tubing and piping markets with skelp as flat rolled coil product, discrete plate or continuous mill plate in various alloys. Uniti Titanium, our joint venture, supplies welded and seamless titanium tubing, welded pipe, and skelp in flat rolled coil and discrete plate.
Nickel alloys offer excellent corrosion resistance to many environments, including chlorides and sulfuric acid, and are virtually immune to stress corrosion cracking. Nickel alloys are used in balance of plant applications where components are exposed to high temperatures exhaust or flue gasses or where corrosive condensates are encountered.
Stainless steels offer a wide range of resistance to a variety of environments. Cost effective stainless alloys are used in tanks and coal silos, structural support, bag house components, and many other applications. Alloys such as ATI 304L™ and ATI 316L™ stainless steels may be used in relatively mild environments where chloride pitting is of concern. Lean duplexes, such as ATI 2003®and ATI 2102®, have replaced 300 series in some applications where pitting resistance with higher strength and thermal conductivity is desired. More highly alloyed stainless steels are often used in the water systems for components such as heat exchanger tubing, condenser tubing, service water piping, and other applications where chloride and microbial resistance is needed. For more severe environments, the super austenitic alloy AL-6XN® or the super ferritic alloys SEA-CURE® and AL 29-4C® alloys are used.
ATI's titanium and titanium alloys and titanium tubing offer excellent corrosion resistance in a wide range of demanding process environments including seawater at elevated temperatures. Titanium is resistant to general corrosion, crevice corrosion, microbiologically influenced corrosion (MIC), erosion corrosion and galvanic corrosion making it an ideal material for condensers, and waste water evaporators.