Jul 25 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Welding
Hot Working
Forging
Cold Working
Annealing
Hardening
Applications
Introduction
Super alloy Nicrofer 3220 H is high-strength solid-solution nickel-iron-chromium alloy. It is a slightly modified version of super alloy Incoloy 800. This is due to the controlled carbon content and modified heat treatment. Nicrofer 3220 H is resistant to oxidation, and has good ductility and good creep rupture properties. It can be carburized and nitridated.
The following sections will discuss in detail about super alloy Nicrofer 3220 H.
Chemical Composition
The chemical composition of Nicrofer 3220 H is outlined in the following table.
|
Element |
Content (%) |
|
Nickel, Ni |
30 - 35 |
|
Chromium, Cr |
19 - 23 |
|
Manganese, Mn |
1.5 max |
|
Silicon, Si |
1 max |
|
Copper, Cu |
0.75 max |
|
Aluminum, Al |
0.15 - 0.6 |
|
Titanium, Ti |
0.15 - 0.6 |
|
Carbon, C |
0.05 - 0.1 |
|
Sulfur, S |
0.015 max |
|
Iron, Fe |
Remainder |
Physical Properties
The physical properties of Nicrofer 3220 H are tabulated below.
|
Properties |
Metric |
Imperial |
|
Density |
7.9 g/cm3 |
0.287 lb/in3 |
|
Melting point |
1371°C |
2500°F |
Mechanical Properties
The following table shows mechanical properties of Nicrofer 3220 H.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
500 MPa |
72.5 ksi |
|
Yield strength |
170 MPa |
24.5 psi |
Other Designations
Equivalent materials to Nicrofer 3220 H are listed below:
-
ASTM B163
-
ASTM B407
-
ASTM B408
-
ASTM B409
-
ASTM B514
-
ASTM B564
-
DIN 1.4876
-
DIN 1.4958
Fabrication and Heat Treatment
Machinability
Super alloy Nicrofer 3220 H can be machined using the common processes applied to iron based alloys. This alloy does work-harden during machining and displays higher strength and "gumminess" unlike steels. It is recommended that heavy duty machining equipment and tooling should be used to reduce chatter or work-hardening of the alloy.
Any common commercial coolant can be used during the machining operations. In case of high speed operations such as grinding, turning, or milling, it is best to use water-based coolants. Likewise it is advisable to use heavy lubricants for drilling, broaching, tapping, or boring.
Forming
Super alloy Nicrofer 3220 H can be formed using any of the conventional methods as it is ductile. Since this alloy is stronger than regular steel it will requires a more powerful equipment to perform forming.
Welding
Welding of super alloy Nicrofer 3220 H can be performed using all the traditional welding methods. Matching alloy filler metal should be used. In case that is not available, it is advised that the nearest alloy closest to the chemical composition be used.
Hot Working
Hot working can be performed in the temperature range of 1204-871°C (2200-1600°F).
Forging
Forge at temperatures in the range of 1204-982°C (2200-1800 °F).
Cold Working
Nicrofer 3220 H can be cold formed using all the standard tools.
Annealing
Nicrofer 3220 H can be annealed at 1176° C (2150°F) and air cooled.
Hardening
Super alloy Nicrofer 3220 H hardens only by cold work.
Applications
Nicrofer 3220 H is used found in the following applications areas:
-
Piping for petrochemical plants, heaters and heat exchangers where prolonged exposure to high temperatures is crucial
-
In steam/hydrocarbon reforming for parts such as pigtails, transfer piping, catalyst tubes used in low pressure processes, headers/ collectors/manifolds, and quench-system piping
-
Steam generator tubing in helium cooled, high temperature reactor systems
-
Ethylene pyrolysis tubing in convection and radiant sections with resistance to carburization and good mechanical properties
-
Cracking tubes used in the production of acetic anhydride and ketene
-
Components such as. heat exchangers and piping systems in coal conversion plants