ASTM A533 Grade C and Grade D are both low-alloy, manganese-molybdenum steel plates for pressure vessels, but Grade D offers higher strength and toughness, requiring specific heat treatments (quenching & tempering) and often containing more alloying elements like Nickel (Ni) for superior performance at extreme temperatures, while Grade C is a strong but less demanding alternative, both focusing on weldability and impact resistance for demanding industrial applications. The key differences lie in their specified tensile/yield strengths and chemical composition ranges, making Grade D suitable for even more severe service conditions.
A533 TYPE B Chemical composition% of the Product analysis of grade
|
Grade |
C % |
Mn %(<40mm) |
P% |
S% |
Si% |
Mo% |
Ni% |
|
A533 TYPE B |
0.25 |
1.07-1.82 |
0.035 |
0.035 |
0.13-0.45 |
0.41-0.84 |
0.37-0.73 |
A533 TYPE C Chemical composition% of the Product analysis of grade
|
Grade |
C % |
Mn %(<40mm) |
P% |
S% |
Si% |
Mo% |
Ni% |
|
A533 TYPE C |
0.25 |
1.07-1.82 |
0.035 |
0.035 |
0.13-0.45 |
0.41-0.84 |
0.67-1.03 |
A533 TYPE B Mechanical Property
|
Grade |
Min Yield |
Tensile |
Thicknesss |
Elongation |
|
A533 TYPE B |
485 Mpa |
620-795Mpa |
<50MM |
16% |
A533 TYPE C Mechanical Property
|
Grade |
Min Yield |
Tensile |
Thicknesss |
Elongation |
|
A533 TYPE C |
345 Mpa |
550-690Mpa |
<50MM |
18% |
Key Differences (Grade C vs. Grade D)
Strength: Grade D steels generally have higher minimum yield and tensile strength requirements than Grade C.
Chemical Composition: Grade D often includes Nickel (Ni) as a key alloying element, enhancing toughness, especially at low temperatures, beyond what Grade C provides with its manganese-molybdenum base.
Applications: Grade D is chosen for more critical, demanding pressure vessel applications requiring superior strength and fracture toughness, whereas Grade C serves strong, but less extreme, requirements.
