Jul 24 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Welding
Heat Treatment
Forging
Cold Working
Aging
Applications
Introduction
Super alloy Nicrofer 4722 Co is a wrought nickel-based alloy with excellent high temperature strength, excellent oxidation resistance, and good resistance to stress-corrosion cracking.
The following sections will discuss in detail about super alloy Nicrofer 4722 Co.
Chemical Composition
The chemical composition of Nicrofer 4722 Co is outlined in the following table.
|
Element |
Content (%) |
|
Chromium, Cr |
20.5 - 23 |
|
Iron, Fe |
17 - 20 |
|
Molybdenum, Mo |
8-10 |
|
Silicon, Si |
1 max |
|
Manganese, Mn |
1 max |
|
Cobalt, Co |
0.5 - 2.5 |
|
Copper, Cu |
0.5 max |
|
Aluminum, Al |
0.5 max |
|
Tungsten, W |
0.2 - 1 |
|
Titanium, Ti |
0.15 max |
|
Carbon, C |
0.05 - 0.15 |
|
Phosphorus, P |
0.04 max |
|
Sulfur, S |
0.03 max |
|
Boron, b |
0.008 max |
|
Nickel, Ni |
Remainder |
Physical Properties
The physical properties of Nicrofer 4722 Co are tabulated below.
|
Properties |
Metric |
Imperial |
|
Density |
8.2 g/cm3 |
0.297 lb/in3 |
|
Melting point |
1315°C |
2400°F |
Other Designations
Equivalent materials to Nicrofer 4722 Co are listed below:
|
AMS 5588 |
ASTM B572 |
ASTM B626 |
GE B50A463 |
GE B50TF31 |
|
AMS 5587 |
ASTM B435 |
ASTM B622 |
DIN 2.4665 |
GE B50TF24 |
|
AMS 5536 |
AMS 5798 |
ASTM B619 |
GE B50A436 |
GE B50TF25 |
|
AISI 680 |
AMS 5754 |
ASTM B366 |
DIN 2.4603 |
GE B50T83A |
Fabrication and Heat Treatment
Machinability
Super alloy Nicrofer 4722 Co can be machined using the common processes applied to austenitic 300 series stainless steels.
Forming
Super alloy Nicrofer 4722 Co can be cold formed using conventional tooling and methods.
Welding
Welding of super alloy Nicrofer 4722 Co can be performed using traditional welding methods such as shielded metal arc, resistance welding, and MIG or TIG. Matching alloy filler metal is required. Preheating and/or post heating are not required.
Heat Treatment
Super alloy Nicrofer 4722 Co can be solution annealed at 1176°C (2150° F) followed by rapid cooling.
Forging
Hot forging can be performed using conventional methods.
Cold Working
Nicrofer 4722 Co can be easily cold worked in the same manner as austenitic 300 series stainless steels. The only difference being that this alloy is comparatively stiffer and may require more pressure.
Aging
Nicrofer 4722 Co can be aged after solution heat treatment at temperatures of 649 to 871°C (1200 to 1600 F). Aging will result in a slight increase in strength and hardness with the effect being related to hours of exposure at the aging temperature - the longer the time the greater the effect.
Applications
Nicrofer 4722 Co is used found in the following applications areas:
-
Petrochemical process equipment and gas turbines in the hot combustor zone sections
-
Structural components in industrial furnace applications