ASTM A299 Grade A and Grade B are manganese-silicon carbon steel plates designed for welded boilers and pressure vessels, with the key difference being Grade B offers higher strength (higher carbon/manganese content) for more demanding, higher-pressure/temperature applications, while Grade A is for less severe conditions, both meeting stringent fine grain and killed steel requirements for weldability and service.
Chemical Composition
|
A299 Grade AChemical Composition |
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|
Grade |
The Element Max (%) |
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|
C |
Si |
Mn |
P |
S |
Mo |
|
|
A299 GR.A |
0.28-0.30 |
0.13-0.45 |
0.84 -1.62 |
0.035 |
0.035 |
- |
|
A299 Grade B Chemical Composition |
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|
Grade |
The Element Max (%) |
|||||
|
C |
Si |
Mn |
P |
S |
Mo |
|
|
A299 GR.B |
0.28-0.30 |
0.13-0.45 |
0.84 -1.62 |
0.035 |
0.035 |
- |
Mechanical Property
|
Grade |
A299 Grade AMechanical Property |
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|
Thickness |
Yield |
Tensile |
Elongation |
|
|
A299 GR.A |
mm |
Min Mpa |
Mpa |
Min % |
|
t≦50 |
275-290 |
515-655 |
19 |
|
|
50<t≦200 |
275-290 |
515-655 |
19 |
|
|
Grade |
A299 Grade BMechanical Property |
|||
|
Thickness |
Yield |
Tensile |
Elongation |
|
|
A299 GR.B |
mm |
Min Mpa |
Mpa |
Min % |
|
t≦50 |
310-325 |
550-690 |
19 |
|
|
50<t≦200 |
310-325 |
550-690 |
19 |
|
Key Characteristics
Material Type: Manganese-Silicon Carbon Steel.
Application: Used in the construction of boilers and other pressure vessels.
Production: Must be "killed" steel (deoxidized) and have a fine austenitic grain size.
Differences Between Grades A & B
Grade A: Lower strength, suitable for less critical, lower-pressure applications.
Grade B: Higher strength due to slightly altered chemistry (more manganese/carbon), making it suitable for more severe service conditions, higher pressures, and temperatures.
