Nov 19 2012
Topics Covered
Introduction
Chemical Composition
Physical Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Welding
Heat Treatment
Forging
Cold Working
Applications
Introduction
Super alloys are classified into three types such as cobalt-based, nickel-based, and iron-based super alloys. They have good creep and oxidation resistance, and can function at very high temperatures and severe mechanical stress. They are available in different forms. They are also known as high performance alloys.
Haynes(r) 188 is a cobalt-nickel-chromium-tungsten alloy. It has high temperature strength and oxidation resistance at a temperature of about 1095°C (590°F). The following datasheet gives an overview of Haynes(r) 188.
Chemical Composition
The chemical composition of Haynes(r) 188 is outlined in the following table.
|
Element |
Content (%) |
|
Cobalt, Co |
≥ 37 |
|
Nickel, Ni |
22 |
|
Chromium, Cr |
22 |
|
Tungsten, W |
14 |
|
Iron, Fe |
≤ 3 |
|
Manganese, Mn |
≤ 1.25 |
|
Silicon, Si |
≤ 0.50 |
|
Carbon, C |
≤ 0.15 |
|
Lanthanum, La |
0.040 |
|
Phosphorous, P |
0.020 |
|
Sulfur, S |
0.015 |
Physical Properties
The following table outlines the physical properties of Haynes(r) 188.
|
Properties |
Metric |
Imperial |
|
Density |
8.9 g/cm3 |
0.324 lb/in3 |
|
Melting point |
1330°C |
2425°F |
Other Designations
Other designations that are equivalent to Haynes(r) 188 include:
-
AMS 5608
-
AMS 5772
-
GE B50A712
-
GE B50TF74
-
GE B50TF74A
-
PWA 1042
Fabrication and Heat Treatment
Machinability
Haynes(r) 188 can be machined using conventional machining methods which are used for iron-based alloys. Machining operations are performed using commercial coolants. High-speed operations such as grinding, milling or turning, are performed using water-based coolants.
Forming
Haynes(r) 188 is formed using all conventional techniques.
Welding
Haynes(r) 188 is welded using TIG, MIG, resistance and electron beam welding methods.
Heat Treatment
Haynes(r) 188 is heat treated at 1175°C (2150°F) followed by cooling.
Forging
Haynes(r) 188 is forged by soaking at 1175°C (2150°F). It is then rapidly cooled.
Cold Working
Haynes(r) 188 is cold worked using common methods.
Applications
Haynes(r) 188 finds application in the following areas:
-
Aerospace industry
-
Hot sections of engines in burner cans
-
Commercial industrial applications
-
Afterburner components