LR EH62 and LR EH69 are both high-strength, extra-high-toughness steel grades for shipbuilding (Lloyd's Register), primarily differentiated by their minimum yield strength. EH69 offers superior strength 690 MPa and better fatigue resistance compared to EH62 620 MPa, making EH69 more suitable for high-stress, cyclic loading applications in marine structures.
Key Differences Between LR EH62 and LR EH69: Yield Strength: LR EH69 has a minimum yield strength of 690 MPa, whereas LR EH62 has a minimum yield strength of 620 MPa.
Application & Performance: Due to its higher yield strength and refined microstructure, LR EH69 steel plate provides enhanced fatigue resistance, allowing it to withstand more cycles of loading and unloading in critical ship structures compared to EH62.Toughness: Both are classified as "EH," meaning they maintain excellent notch toughness at very low temperatures -40° C , but EH69 is tailored for higher strength requirements.
Chemical Composition
LR EH62 extra high Strength Chemical Composition | |||||||
Grade | The Element Max (%) | ||||||
C | Si | Mn | P | S | Al | N | |
LR EH62 | 0.20 | 0.55 | 1.70 | 0.030 | 0.030 | 0.015 | 0.020 |
Nb | V | Ti | Cu | Cr | Ni | Mo | |
0.02-0.05 | 0.03-0.10 | 0.02 |
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LR EH69 extra high Strength Chemical Composition | |||||||
Grade | The Element Max (%) | ||||||
C | Si | Mn | P | S | Al | N | |
LR EH69 | 0.20 | 0.55 | 1.70 | 0.030 | 0.030 | 0.015 | 0.020 |
Nb | V | Ti | Cu | Cr | Ni | Mo | |
0.02-0.05 | 0.03-0.10 | 0.02 |
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Mechanical Property
LR EH62 extra high strength property | |||||||
Grade |
| Mechanical Property | Charpy V Impact Test | ||||
Thickness | Yield | Tensile | Elongation | Degree | Energy 1 | Energy 2 | |
LR EH62 | mm | Min Mpa | Mpa | Min % | -40 | J | J |
t≤50 | 620 | 720-890 | 17% | 41 | 62 | ||
50＜t≤70 | 620 | 720-890 | 17% | 41 | 62 | ||
70＜t≤100 | 620 | 720-890 | 17% | 41 | 62 | ||
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal | |||||||
LR EH69 extra high strength property | |||||||
Grade |
| Mechanical Property | Charpy V Impact Test | ||||
Thickness | Yield | Tensile | Elongation | Degree | Energy 1 | Energy 2 | |
LR EH69 | mm | Min Mpa | Mpa | Min % | -40 | J | J |
t≤50 | 690 | 770-940 | 16% | 46 | 69 | ||
50＜t≤70 | 690 | 770-940 | 16% | 46 | 69 | ||
70＜t≤100 | 690 | 770-940 | 16% | 46 | 69 | ||
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal | |||||||
