Compositions, Properties and applications of Maraging steel

1. MARAGING STEEL
.

2. Maraging steels
• Which are low carbon, highly alloyed steels.
• Which are very high strength
COMPOSITION:
• 18% NICKEL 7% COBALT
• Less than 0.05% carbon content
• Small amount of other elements such as
TITANIUM

3. • The above compositions develop martensite up on
cooling ( by air quenching)
• To achieve high tensile strength- Below the
austenitizing (723 ˚c) temperature
• Various compositions of maraging steels:
– Ni-18% Co-8.5%
– Mo-3% Ti-0.2%
– Al-0.10% C-0.01%

4. TO ACHIEVE HIGH TENSILE
STRENGTH
• Maraging steel from the austenitizing temperature (723 ͦc)
Air cooled
Martensite steel --- which having high ductile and tough
Precipitation Hardening done on the steel ---- to achieve
high tensile strength

5. MARAGING STEEL MICRO STRUTURE

6. CHARACTERISTICS
•Due to the low carbon content maraging steels have good
machinability.
• Prior to aging, they may also be cold rolled to as much as
80–90% without cracking.
•Maraging steels offer good weldability,
•When heat-treated the alloy has very little dimensional
• Due to the high alloy content maraging steels have a high
hardenability.
•The steels can be nitrided to increase case hardness, and
polished to a fine surface finish.

7. APPLICATIONS
1. HEAT RESISTANCE STEELS:
– Valves in IC engines, Steam and gas turbines, etc.,
2. HADFIELD’S MANGANESE STEELS:
– Pneumatic drill bits, Rock crusher, etc.,
3. FREE MACHINING STEELS:
– Reduce rubbing against cutting tool
4. MAGNET ALLOYS:
– Permanent magnet made from iron along with nickel.

8. APPLICATIONS
•Shafts
•Barrel For Firing Guns
•Dies In Casting
•Extrusion Rams
•Space Vehicle Cases
•Components Subject To Impact Fatigue, Such As Print
Hammers Or clutches.