LR grade A steel is a kind of hot rolled general tensile strength steel, and the like LR Grade B, LR Grade D and LR Grade E. LR steels come 4 grades in ordinary-strength steel for shipbuilding and grade A is the lowest one of them. The LR A grade steel plates have yield strength of 34,100 psi (235 MPa), and ultimate tensile strength of 58,000 - 75,500 psi (400-520 MPa).
LR Grade A shipbuilding Steel Application:
LR A grades of steel plate are almost exclusively used in the Shipbuilding Industry for the construction of structural parts of ships, barges and marine equipment. LR A Shipbuilding steel plates also can be used for ship repairing, the offshore oil drilling platform, the platform pipe joints and other components.
|
LR A general Strength Chemical Composition |
|||||||
|
Grade |
The Element Max (%) |
||||||
|
C |
Si |
Mn |
P |
S |
Al |
N |
|
|
LR A |
0.21 |
0.50 |
2.5×C% |
0.035 |
0.035 |
|
|
|
Nb |
V |
Ti |
Cu |
Cr |
Ni |
Mo |
|
|
|
|
|
|
|
|
|
|
Crack Sensitivity: Pcm = (C+Si/30+Mn/20+Cu/20+Ni/60+Cr/20+Mo/15+V/10+5B)%
Carbon Equivalent: Ceq = 【C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15】%
|
LR A general strength property |
|||||||
|
Grade |
|
Mechanical Property |
Charpy V Impact Test |
||||
|
Thickness |
Yield |
Tensile |
Elongation |
Degree |
Energy 1 |
Energy 2 |
|
|
LR A |
mm |
Min Mpa |
Mpa |
Min % |
20 |
J |
J |
|
t≤50 |
235 |
400-520 |
22% |
20 |
27 |
||
|
50＜t≤70 |
235 |
400-520 |
22% |
24 |
34 |
||
|
70＜t≤100 |
235 |
400-520 |
22% |
27 |
41 |
||
|
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal |
|||||||
