Jul 25 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Welding
Hot Working
Forging
Cold Working
Annealing
Hardening
Applications
Introduction
Super alloy Nicrofer 3220 LC is a Ni-Cr-Fe alloy that is built to resist high temperature oxidation. This alloy is sought for its improved performance or strength at high temperature. It is an upgraded version of stainless steel 300 series.
The following sections will discuss in detail about super alloy Nicrofer 3220 LC.
Chemical Composition
The chemical composition of Nicrofer 3220 LC 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 |
0.1 max |
|
Sulfur, S |
0.015 max |
|
Iron, Fe |
Remainder |
Physical Properties
The physical properties of Nicrofer 3220 LC are tabulated below.
|
Properties |
Metric |
Imperial |
|
Density |
7.9 g/cm3 |
0.287 lb/in3 |
|
Melting point |
1371°C |
2500°F |
Other Designations
Equivalent materials to Nicrofer 3220 LC are listed below:
-
AMS 5766
-
AMS 5871
-
ASTM B163
-
ASTM B366
-
ASTM B407
-
ASTM B408
-
ASTM B409
-
ASTM B514
-
ASTM B515
-
ASTM B564
-
DIN 1.4876
Fabrication and Heat Treatment
Machinability
Super alloy Nicrofer 3220 LC 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 LC 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 LC 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. The weld beads should be slightly convex. Pre-heating is not required.
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 1232-1010°C (2250-1850° F).
Cold Working
Nicrofer 3220 LC can be cold worked using all the standard tools.
Annealing
After cold working Nicrofer 3220 LC may require annealing. Annealing can be done at 982 °C (1800°F) for 15 min and air cooled. The alloy must not be heated above 982° C (1800°F).
Hardening
Super alloy Nicrofer 3220 LC hardens only by cold work.
Applications
Nicrofer 3220 LC is used found in the following applications areas:
-
Heat treating equipment and fixtures
-
Heat exchangers
-
Sheathing for electric resistance alloy tubular heating elements.