ASTM A285 Grade B For Pressure Vessel Plate

Dimension Range

Width: Please inquire for plate widths less than 72 in. or greater than 120 in.

Length: Please inquire for plate lengths less than the listed minimum or greater than the listed maximum.

Mechanical Properties

Tensile testing is performed in the transverse direction.

Q1: How does ASTM A285 Grade B differ chemically from Grade A?
Higher carbon (≤0.22% vs ≤0.17%) and manganese (0.90% max vs 0.90%) for increased strength
Same P/S limits (P≤0.035%, S≤0.040%)
No alloying elements (remains plain carbon steel)
Q2: What are the key mechanical properties of Grade B?
Property Requirement
Tensile Strength 380-515 MPa (55-75 ksi)
Yield Strength ≥205 MPa (30 ksi)
Elongation (2") ≥25%
Note: ~25% stronger than Grade A but less ductile.
Q3: Is impact testing mandatory for ASTM A285 Grade B?
Not required by default
If specified (per ASTM A20 S5), Charpy V-notch testing applies:
Minimum 20J (15 ft-lbf) at 16°C (60°F)
Still not recommended for subzero temperatures

Q4: What are typical applications for Grade B?
Medium-pressure vessels (≤1.5 MPa design pressure)
Oil/water storage tanks
Boiler shells

Q5: What welding precautions apply to Grade B?
Preheat: 50-100°C for thickness >25mm
Electrodes: E7018 for SMAW, ER70S-6 for GMAW
PWHT: Optional below 32mm thickness
Risk: Higher carbon content increases crack sensitivity vs Grade A.