DQ63 is a premium high-strength ship plate grade adhering to global marine standards, distinguished by its exceptional low-temperature toughness and structural reliability. A core characteristic of DQ63 is its ability to maintain ductility and impact resistance at temperatures as low as -40°C, achieved through precise alloying (0.16% max carbon, 1.60% max manganese) and niobium-induced grain refinement. It retains the high strength of AQ63—minimum yield strength of 450 MPa and tensile strength of 570-720 MPa—while adding cold-weather performance. Rigorous quality testing, including Charpy V-notch impact tests at -40°C, ensures it meets strict toughness criteria for cold marine environments.
The main function of DQ63 is to safeguard structural integrity in ships and offshore structures operating in sub-polar regions, where low temperatures risk brittle fracture in standard grades. Its standout advantages center on low-temperature resilience: unlike AQ63, it resists cracking even in freezing conditions, minimizing catastrophic failure risks. It also maintains excellent weld integrity—welded joints retain low-temperature toughness when using appropriate techniques, eliminating structural weak points. Additionally, DQ63 offers good formability, allowing it to be shaped into complex components like curved hull sections without performance loss.
DQ63 is indispensable for cold marine operations. It is extensively used in building ice-class cargo ships, offshore supply vessels, and research vessels navigating sub-polar waters such as the North Sea. Key applications include bow sections exposed to ice impact, hull plating in cold-water zones, and load-bearing bulkheads that endure both heavy loads and low temperatures. It is also a top choice for offshore oil platforms in cold coastal areas, as it resists freezing temperatures and seawater corrosion. Furthermore, DQ63 serves in naval vessels designed for cold-water missions, where structural resilience in extreme weather is a strategic priority.
