4.2.3 Martensitic Grades

Martensitic stainless steels usually contain a maximum of 14% chromium, except types 440A and 440B, which contain 16% to 18% chromium. Carbon is added in sufficient amounts to promote hardening. Other elements, when present, are usually restricted to 2% or 3%. They exhibit excellent strength, and, unlike most other stainless grades, they are magnetic. Martensitic stainless steels are hardened and tempered using processes similar to those used for as alloy steels. Typical tempering temperatures range from 540 to 620°C (1000 to 1150°F).

Commonly used martensitic forging grades include:

SAE
No
AMS
No
Percent Composition
C
Cr
Mo
Ni
S1
Si
403 A4732
0.2
12
 
   
   
 
410 5613
0.12
12
 
  
   
1
416 5610
   
13
0.6
   
0.15
 
420 5621
0.2
13
 
 
  
 
431 A4732
0.2
16
 
2
   
 
440A 5631
0.7
17
0.7
 
 
 
440C 5630
1.1
17
0.7
  
   
 

1Sulphur reduces forgeability
2ASTM specification

SAE grades include several others that have special purposes and, while not commonly forged, are just as forgeable as these listed grades.

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Martensitic stainless steels usually contain a maximum of 14% chromium, except types 440A and 440B, which contain 16% to 18% chromium. Carbon is added in sufficient amounts to promote hardening. Other elements, when present, are usually restricted to 2% or 3%. They exhibit excellent strength, and, unlike most other stainless grades, they are magnetic. Martensitic stainless steels are hardened and tempered using processes similar to those used for as alloy steels. Typical tempering temperatures range from 540 to 620°C (1000 to 1150°F).

Commonly used martensitic forging grades include:

SAE
No
AMS
No
Percent Composition
C
Cr
Mo
Ni
S1
Si
403 A4732
0.2
12
 
   
   
 
410 5613
0.12
12
 
  
   
1
416 5610
   
13
0.6
   
0.15
 
420 5621
0.2
13
 
 
  
 
431 A4732
0.2
16
 
2
   
 
440A 5631
0.7
17
0.7
 
 
 
440C 5630
1.1
17
0.7
  
   
 

1Sulphur reduces forgeability
2ASTM specification

SAE grades include several others that have special purposes and, while not commonly forged, are just as forgeable as these listed grades.

Return to Table of Contents

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Martensitic stainless steels usually contain a maximum of 14% chromium, except types 440A and 440B, which contain 16% to 18% chromium. Carbon is added in sufficient amounts to promote hardening. Other elements, when present, are usually restricted to 2% or 3%. They exhibit excellent strength, and, unlike most other stainless grades, they are magnetic. Martensitic stainless steels are hardened and tempered using processes similar to those used for as alloy steels. Typical tempering temperatures range from 540 to 620°C (1000 to 1150°F).

Commonly used martensitic forging grades include:

SAE
No
AMS
No
Percent Composition
C
Cr
Mo
Ni
S1
Si
403 A4732
0.2
12
 
   
   
 
410 5613
0.12
12
 
  
   
1
416 5610
   
13
0.6
   
0.15
 
420 5621
0.2
13
 
 
  
 
431 A4732
0.2
16
 
2
   
 
440A 5631
0.7
17
0.7
 
 
 
440C 5630
1.1
17
0.7
  
   
 

1Sulphur reduces forgeability
2ASTM specification

SAE grades include several others that have special purposes and, while not commonly forged, are just as forgeable as these listed grades.

Return to Table of Contents

', )