Stainless
Steel Categories: Martensitic
Martensitic
stainless steels, typified by types 410/420/440,
containing about 12Cr and 0.1C wt% as
the basic composition. They are not as
corrosion resistant as the other classes,
but are extremely strong and tough as
well as highly machineable, and can be
hardened by heat treatment. They contain
11.5 to 18% chromium and significant amounts
of carbon. Some grades include additional
alloying elements in small quantities.
| Martensitic
Stainless Steels |
| Grade |
C |
Mn |
Si |
Cr |
Ni |
Mo |
P |
S |
Comments/Applications |
|
410
|
0.15
|
1.0
|
0.5
|
11.5-13.0
|
-
|
-
|
0.04
|
0.03
|
The basic
composition. Used for cutlery, steam
and gas turbine blades and buckets,
bushings... |
|
416
|
0.15
|
1.25
|
1.0
|
12.0-14.0
|
-
|
0.60
|
0.04
|
0.15
|
Addition
of sulphur for machinability, used
for screws, gears etc. 416
Se replaces sulphur by selenium. |
|
420
|
0.15-0.40
|
1.0
|
1.0
|
12.0-14.0
|
-
|
-
|
0.04
|
0.03
|
Dental
and surgical instruments, cutlery....
|
|
431
|
0.20
|
1.0
|
1.0
|
15.0-17.0
|
-
|
1.25-2.0
|
0.04
|
0.03
|
Enhanced
corrosion resistance, high strength.
|
|
440A
|
0.60-0.75
|
1.0
|
1.0
|
16.0-18.0
|
-
|
0.75
|
0.04
|
0.03
|
Ball
bearings and races, gauge blocks,
molds and dies, cutlery. |
|
440B
|
0.75-0.95
|
1.0
|
1.0
|
16.0-18.0
|
-
|
0.75
|
0.04
|
0.03
|
As 440A,
higher hardness |
|
440C
|
0.95-1.20
|
1.0
|
1.0
|
16.0-18.0
|
-
|
0.75
|
0.04
|
0.03
|
As 440B,
higher hardness |
|
|
