HAYNES® 556® alloy for Rotary Calciners Tech Brief

 

For Rotary Calciners & Reaction Vessels at High Temperatures

Metallurgical and chemical processing performed in rotary calciners or reaction vessels can place severe demands upon process equipment. Temperatures at 1800ºF to 2000ºF (982ºC to 1093ºC), when combined with corrosive environments, can be a designer’s headache and a maintenance department’s nightmare. Designing strength into a vessel by using thick sections of stainless steel, or nickel alloys (such as No. 600), is not effective if high-temperature corrosion causes localized or even general wall thinning.

The answer? HAYNES® 556® alloy. 556® alloy is the one material which not only resists most forms of high-temperature corrosion, but also provides a strength advantage over stainless steel or nickel alloys. That can mean years of additional service life.

556® alloy offers still another opportunity. Take advantage of the increased strength by designing with thinner sections. This can mean increased process efficiency, significantly longer vessel service life, and upfront material costs still comparable to those for thicker-section nickel alloy construction.

Alloy Description

HAYNES® 556® alloy is an iron-nickel-chromium-cobalt alloy that combines effective resistance to sulfidizing, carburizing, and chlorine-bearing environments at high temperatures with good oxidation resistance, fabricability, and excellent high-temperature strength. It has also been found to resist corrosion by molten chloride salts and molten zinc.

HAYNES® 556® alloy is highly used for service at elevated-temperatures in moderately to severely corrosive environments. Applications include tubing and structural members in waste heat recuperators, super heaters, and internals in municipal and chemical waste incinerators; power plant burner buckets, air nozzles and fluidized bed combustor heat exchangers and internals; high speed furnace fans, galvanizing bath hardware and brazing fixtures; and high-temperature rotary calciners and kilns. There are also additional uses in chemical/petrochemical process and pulp and paper industries.

Nominal Composition

Iron Balance
Nickel 20
Cobalt 18
Chromium 22
Molybdenum 3
Tungsten 2.5
Tantalum 0.6
Nitrogen 0.2
Silicon 0.4
Manganese 1
Aluminum 0.2
Carbon 0.1
Lanthanum 0.02
Zirconium 0.02

Typical Tensile Properties, Plate

Test Temperature 0.2% Yield Strength Ultimate Tensile Strength Elongation
°F °C ksi MPa ksi MPa %
RT RT 55 375 116 805 51
1000 540 31 210 90 625 60
1200 650 31 210 83 575 57
1400 760 29 200 69 470 53
1600 870 28 190 49 340 69
1800 980 19 130 31 210 84
2000 1095 9 60 16 110 95

Typical Rupture Properties, Plate

Test Temperature Typical Rupture Properties: Stress Required to Produce Rupture in Hours Shown
100 h 1,000 h 10,000 h
°F °C ksi MPa ksi MPa ksi MPa
1400 760 25.0 172 17.5 121 11.9 82
1500 815 17.0 117 11.8 81 7.8 53
1600 870 11.5 79 7.5 52 4.9 34
1700 915 7.6 52 4.8 33 3.0 21
1800 980 4.8 33 3.0 21 1.9 13

Typical Room Temperature Physical Properties

HAYNES® 556® alloy for Rotary Calciners Tech Brief 4

Physical Property British Units Metric Units
Density
0.297 lb/in3
8.23 g/cm3
Electrical Resistivity 37.5 µohm-in 95.2 µohm-cm
Modulus of Elasticity
29.7 x 106 psi
206 GPA
Thermal Conductivity

77 Btu-in/ft2-h-°F

11.1 W/m-°C
Specific Heat 0.111 Btu/lb-°F 464 J/Kg-°C

Environmental Resistance

Oxidation in Air – Excellent at 2000°F (1095°C)

Sulfidation – Second only to Co-base alloys

Molten Chloride Salts – Equal to alloy X

Chlorination – Very good to 1650°F (900°C)

Carburization – Equal to alloy 800H

Molten Zinc – Best Available