Grade B
shipbuilding steel is a kind of hot rolled general tensile strength steel. It comes 4 grades in ordinary-strength steel Grade A, Grade B, Grade D, and
Grade E for shipbuilding and Grade A is the lowest one of them. Yield point for all ordinary-strength ship steels is specified as 34,000 psi (235 MPa), Ultimate tensile strength of ordinary strength alloys is 58,000 - 71,000 psi (400-490 MPa). On certified steels, the plates are marked with the Grade Bnd a preceding Classification Society Mark like"AB/", AB/B; CCS, CCS B; RINA, RINA A etc.
Grade B Shipbuilding Steel Plates Specification:
Thickness: 3-150mm
Width: 1220-4200mm
Length: 5000-17000mm
Notes: coil thickness ≤ 25mm
Grade B Shipbuilding Steel Chemical Composition (%, by weight)
| Grade |
% max |
| C |
Si |
Mn |
P |
S |
| GR. A |
0.21 |
0.50 |
2.5×C |
0.035 |
0.035 |
| GR. B |
0.21 |
0.35 |
0.60 |
0.035 |
0.035 |
| GR. C |
0.21 |
0.10~0.35 |
0.60 |
0.035 |
0.035 |
| GR. D |
0.18 |
0.10~0.35 |
0.70 |
0.035 |
0.035 |
Grade B Shipbuilding Steel Mechanical Properties:
| Grades |
Yield strength
MPa |
Tensile strength
MPa |
Elongation
Min,% |
| 200mm |
50mm |
| Grade A,B,C,D |
400~520 |
235min |
21 |
24 |
Grade B Shipbuilding Steel Application
Grade B shipbuilding steel plates are almost exclusively used in the Shipbuilding Industry for the construction of structural parts of ships, barges and marine equipment. Grade B shipbuilding steel also can be used for ship repairing, the offshore oil drilling platform, the platform pipe joints and other components.
Grade B Shipbuilding Steel Heat Analysis
Grade B shipbuilding steel plates in all thicknesses shall be normalized or thermo-mechanical control processed while shapes and bars in all thicknesses shall be heat treated and rolled. Heat analysis of ordinary strength structural steel shall be used to determine the required chemical composition for carbon, manganese, phosphorus, sulfur, nickel, chromium, molybdenum, silicon, and copper.
Grade B shipbuilding steel products are fabricated by Katalor Industry in form of plates, coils, sheets, bars, profiles, bulb flats, and angle steel.
