Overview
LR AH32 is a higher-strength structural steel plate certified by Lloyd's Register for shipbuilding and marine applications. The A grade signifies impact testing at 0 degrees C, suitable for general marine environments. LR AH36 is a higher-strength marine steel plate also certified by LR with impact toughness tested at 0 degrees C, designed for more demanding structural applications in shipbuilding and offshore platforms.
Mechanical Properties
LR AH32 has a minimum yield strength of 315 MPa, tensile strength of 440 to 590 MPa, and minimum elongation of 22 percent, with impact energy of 20 J transverse and 31 J longitudinal at 0 degrees C for thicknesses up to 50 mm. LR AH36 has a minimum yield strength of 355 MPa, tensile strength of 490 to 630 MPa, and minimum elongation of 21 percent, with impact energy of 24 J transverse and 34 J longitudinal at 0 degrees C.
Chemical Composition
Both grades limit carbon to 0.18 percent and manganese to 0.90 to 1.60 percent, with silicon 0.05 percent, phosphorus and sulfur to 0.035 percent, and microalloying niobium, vanadium, and titanium. The composition is nearly identical, with strength differences achieved through processing.
Applications
AH32 is widely used for hull structures and general shipbuilding components where standard higher-strength properties suffice. AH36 is used for more demanding load-bearing applications requiring superior strength, such as primary hull structures of larger vessels and offshore platform components.
Selection Guidance
Choose AH32 for general high-strength hull construction where the lower cost is advantageous. Choose AH36 where the design requires the higher yield strength of 355 MPa for load-bearing members.
Frequently Asked Questions
Q: What is the yield strength of LR AH32?
A: 315 MPa minimum, with tensile strength of 440 to 590 MPa and 22 percent elongation.
Q: What is the yield strength of LR AH36?
A: 355 MPa minimum, with tensile strength of 490 to 630 MPa and 21 percent elongation.
Q: What impact temperature applies?
A: 0 degrees C for both grades, suitable for general marine environments.
Q: What are the main applications?
A: Hull structures and general shipbuilding for AH32; more demanding load-bearing applications for AH36.
Q: Do the grades differ in composition?
A: The limits are nearly identical; the strength difference comes from processing.
Q: What is the elongation difference?
A: AH32 requires 22 percent and AH36 21 percent minimum elongation.
For LR AH32 and AH36 certified marine steel plate quotations, contact our sales team.
