Heat Treatment Techniques for CCS EH32 Shipbuilding Steel Plates

1. Normalising Heat Treatment

The normalising process involves heating CCS EH32 shipbuilding steel plates to 850–900°C, holding at this temperature for an appropriate duration, and then cooling to room temperature in air. This process refines the grain structure, eliminates internal stresses generated during hot rolling, and significantly improves the uniformity and ductility of the steel plates. EH32 steel plates treated by normalising exhibit stable properties and are relatively straightforward to process. They are suitable for thick plates exceeding 50 mm in thickness and are commonly used in primary hull structures and load-bearing components of offshore platforms.

2. TMCP (Thermomechanical Control Processing) Process

TMCP is a process that combines controlled rolling with accelerated cooling, enabling production without the need for secondary heat treatment. This technology enables CCS EH32 shipbuilding steel plates to achieve a finer grain structure, higher toughness and superior weldability. Compared to normalised steel, TMCP-treated EH32 steel plates have a lower carbon equivalent, which reduces preheating requirements during welding, thereby lowering the shipyard’s overall construction costs. This process is the preferred solution for thin and medium-gauge plates with a thickness of less than 50 mm.