LR Grade DH32 Shipbuilding Steel Plate - High-Strength Marine Structural Steel

1. What is LR Grade DH32 shipbuilding steel plate?

LR Grade DH32 shipbuilding steel plates are high-strength hull structural steel plates certified by Lloyd’s Register (LR) for use in low-temperature environments. They feature excellent impact toughness at -20°C, stable high-strength mechanical properties, good weldability and formability, as well as outstanding resistance to seawater corrosion and fatigue.

LR Grade DH32 shipbuilding steel plates effectively resist wave impact, structural fatigue, and low-temperature brittle fracture in complex marine environments. They are widely used in ocean-going vessels, offshore platforms in cold regions, offshore engineering facilities, marine auxiliary structures, and port equipment.

2. Meaning of the Designation

LR: Certified by Lloyd’s Register (LR)

D: Quality grade D (Must meet the requirements of the impact test at -20°C)

H: High strength

32: Minimum yield strength: 315 MPa (≈ 32 kgf/mm²)

Chemical Composition (Heat Analysis, wt %)

Carbon Equivalent (wt %)

Calculation formula (IIW): CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15

Mechanical Properties

Impact Properties

1. Shipbuilding

Used in critical components of medium- and large-sized ocean-going vessels, bulk carriers, oil tankers, and container ships, including main hull plates, load-bearing decks, reinforced bulkheads, and bottom load-bearing structures.

2. Offshore Engineering

Suitable for oil and gas drilling platforms in temperate and cold waters, offshore wind turbine foundations, hull structures of Floating Production, Storage, and Offloading (FPSO) units, as well as core load-bearing components and support facilities for shallow-water engineering equipment.

3. Port Auxiliary Equipment

Used in critical load-bearing structures of port equipment such as floating cranes, offshore support vessels, and dredgers operating in seasonal low-temperature and cold environments.

4. Ship Repair and Structural Reinforcement

Used for hull structure replacement, localized reinforcement, and safety upgrades for ocean-going vessels and coastal facilities.

Key Advantages of LR Grade DH32 Shipbuilding Steel Plates

1. Authoritative Certification by LR

Officially certified by Lloyd’s Register (LR), this steel fully meets the requirements for global shipyard tenders, offshore engineering project delivery, and cross-border customs clearance, ensuring smooth project acceptance.

2. Stable, High-Strength Mechanical Properties

With stable yield strength and tensile strength, this steel can effectively withstand long-term alternating structural stresses, wave impacts, and seawater pressure in medium-load offshore engineering projects.

3. Excellent Low-Temperature Toughness

It maintains stable impact toughness at -20°C, effectively mitigating the risk of structural brittle fracture in cold waters and low-temperature marine environments.

4. Good Weldability and Workability

It is easy to cut and weld with precision on-site and does not require complex post-weld heat treatment, significantly improving construction efficiency and reducing overall project costs.

5. Reliable Resistance to Marine Corrosion

It combines excellent resistance to seawater corrosion, salt spray aging, and wet-dry cycling, ensuring long-term structural stability and extending service life.

6. Superior Fatigue Resistance

An optimized internal microstructure enhances the structure’s fatigue resistance, effectively reducing the risk of fatigue failure in ships and offshore facilities during long-term operation.

• Performance Comparison and Selection Guide for LR AH32/DH32/EH32 Marine Steel Plates