Difference between LR DH32 and LR DH36 steel plate

Mar 11, 2026 Leave a message

LR DH32 is a higher-strength structural steel plate certified by Lloyd's Register (LR) for shipbuilding and marine applications. The "D" grade signifies it is impact tested at -20°C . It has a minimum yield strength of 315 MPa (46 ksi) and tensile strength ranging from 440 to 590 MPa (64-83 ksi), with minimum elongation of 22% . The chemical composition is strictly controlled with carbon ≤0.18% and manganese 0.90-1.60% . It is widely used for hull structures, offshore platforms, and marine engineering components.

 

LR DH36 is also a higher-strength structural steel plate certified by LR, with the same impact test temperature of -20°C . The "36" denotes a minimum yield strength of 355 MPa and tensile strength ranging from 490 to 630 MPa, with minimum elongation of 21% . The chemical composition is similar to DH32 with carbon ≤0.18% and manganese 0.90-1.60%, though DH36 may contain microalloying elements like Nb and V to achieve its higher strength . This grade is designed for more demanding load-bearing applications in shipbuilding, including hull shells, longitudinal stiffeners, and primary structures.

 

Both LR DH32 and LR DH36 are LR-certified higher-strength marine steels with impact toughness tested at -20°C, ensuring reliable performance in cold marine environments . Their primary difference lies in strength level: DH32 offers a minimum yield strength of 315 MPa with tensile strength of 440-590 MPa, suitable for general high-strength hull construction and secondary structures, while DH36 provides a higher minimum yield strength of 355 MPa with tensile strength reaching 490-630 MPa, designed for more demanding load-bearing applications requiring superior strength . Both grades feature controlled chemical composition and maintain good weldability for critical marine service.

 

Chemical Composition

 

LR DH32 high Strength Chemical Composition

Grade

The Element Max (%)

C

Si

Mn

P

S

Al

N

LR DH32

0.18

0.05

0.9-1.6

0.035

0.035

0.015

 

Nb

V

Ti

Cu

Cr

Ni

Mo

0.02-0.05

0.03-0.10

0.02

0.35

0.20

0.40

0.08

 

LR DH36 high Strength Chemical Composition

Grade

The Element Max (%)

C

Si

Mn

P

S

Al

N

LR DH36

0.18

0.05

0.9-1.6

0.035

0.035

0.015

 

Nb

V

Ti

Cu

Cr

Ni

Mo

0.02-0.05

0.03-0.10

0.02

0.35

0.20

0.40

0.08

 

Mechanical Property

 

LR DH32 high strength property

Grade

 

Mechanical Property

Charpy V Impact Test

Thickness

Yield

Tensile

Elongation

Degree

Energy 1

Energy 2

LR DH32

mm

Min Mpa

Mpa

Min %

-20

J

J

t≤50

315

440-590

22%

20

31

50<t≤70

315

440-590

22%

26

38

70<t≤100

315

440-590

22%

31

46

Note: Energy 1 is transverse impact test, Energy 2 is longitudinal

 

LR DH36 high strength property

Grade

 

Mechanical Property

Charpy V Impact Test

Thickness

Yield

Tensile

Elongation

Degree

Energy 1

Energy 2

LR DH36

mm

Min Mpa

Mpa

Min %

-20

J

J

t≤50

355

490-630

21%

24

34

50<t≤70

355

490-630

21%

27

41

70<t≤100

355

490-630

21%

34

50

Note: Energy 1 is transverse impact test, Energy 2 is longitudinal