Chemical composition and mechanical properties
Chemical Composition
Steel grade |
C |
Si |
Mn |
P |
S |
Als |
Grade AH32 |
≤0.18 |
≤0.50 |
0.9-1.6 |
≤0.035 |
≤0.035 |
≥0.015 |
Grade DH32 |
≤0.18 |
≤0.50 |
0.9-1.6 |
≤0.035 |
≤0.035 |
≥0.015 |
Grade EH32 |
≤0.18 |
≤0.50 |
0.9-1.6 |
≤0.035 |
≤0.035 |
≥0.015 |
Grade FH32 |
≤0.18 |
≤0.50 |
0.9-1.6 |
≤0.035 |
≤0.035 |
≥0.015
|
Grade D, E (DH32, DH36, EH 32, EH 36)
Grade D and E series (inlcuding AH32/36, DH32, DH36, EH32, EH36) shipbuilding steel plates require good low temperature toughness and good welding performance. The production high-strength shipbuilding steel plate needs to be normalized by means of controlled rolling and controlled cooling or heat treatment processes with more complete equipment. At the same time, the internal steel purity of the supplied billets is required to be high, especially the content of S, P, N, 0 and H in the steel should be strictly controlled.
Alloy Elements Added to Improve Toughness
In order to ensure the performance of high-strength ship plates, micro-alloying technology is adopted. By adding Nb, V, Ti and other alloying elements to the steel, combined with the controlled rolling process, the grain is refined and the toughness is improved.
Direction of Development for Shipbuilding Plate
High strength, high specification, with the ship's large-scale and safety, and changes in coating specifications, the demand for ordinary A-class panels is gradually reduced, and the demand for high-strength panels is increasing, which is concentrated in large ships of 5m wide. Plate, 200-300mm thickness special thick ship board.
Mechanical Properties
Steel grade |
Yield point/MPa |
Tensile point /MPa |
Elongation/% |
Temperature/° C |
V-type impact test |
Akv/J |
≤50MM |
50-70MM |
70-100MM |
Grade AH32 |
≥315 |
440-570 |
≥22 |
0 |
31/22 |
38/26 |
46/31 |
Grade DH32 |
≥315 |
440-570 |
≥22 |
-20 |
31/22 |
38/26 |
46/31 |
Grade EH32 |
≥315 |
440-570 |
≥22 |
-40 |
31/22 |
38/26 |
46/31 |
Grade FH32 |
≥315 |
440-570 |
≥22 |
-60 |
31/22 |
38/26 |
46/31 |