Difference between LR EH32 and LR EH36 steel plate

LR EH32 and LR EH36 are high-strength shipbuilding steel plates certified by Lloyd's Register (LR). The "EH" designation stands for Extra High-strength with High toughness. They are primarily designed for critical structural components in ships and offshore installations, such as hull plating in large container ships, icebreakers, and offshore platforms, where superior strength, excellent weldability, and exceptional low-temperature toughness are paramount for safety and structural integrity in harsh environments.

Key Differences:

The fundamental distinction lies in their minimum yield strength. LR EH32 offers a yield strength of 315 MPa (the '32' represents 32 kgf/mm²), while LR EH36 provides a higher yield strength of 355 MPa (36 kgf/mm²). This makes EH36 the stronger of the two, allowing for weight reduction in design.

To achieve this higher strength while maintaining the demanding toughness requirements (particularly at temperatures as low as -40°C or -60°C), EH36 typically requires a more refined chemical composition involving micro-alloying elements (like Niobium, Vanadium) and stricter control during the thermo-mechanically controlled processing (TMCP). Consequently, EH36 generally has a slightly higher carbon equivalent, which can necessitate more precise welding procedures (preheat/interpass temperature control) compared to EH32 to avoid cold cracking and preserve the heat-affected zone properties.

Chemical Composition

Mechanical Property