TMCP ABS EH40 steel plates making technology

In order to ensure the safety and reliability of the ship, the classification societies have made strict rules of chemical composition, mechanical properties and delivery conditions for different specifications and grades of ABS EH40 steel plates.

In order to meet low temperature toughness, high strength and excellent welding performance of high quality level ABS EH40 steel plates and EH40 shipbuilding steel, TMCP ABS EH40 steel plates and EH40 marine steel plates adopt composition design of low carbon content, medium manganese content, ultra low sulfur, Nb, Ti micro alloying, control the organization of Cr alloying. Meanwhile, Cu, Ni etc. alloy elements are properly added to compensate strength.

The steelmaking process adopt smelting technology of low carbon, low sulfur and inclusion morphology control of pure steel, to ensure the low temperature impact toughness of thick ABS EH40 steel plates. The molten iron is smelted through a converter and then refined out of the furnace to be cast into a 300mm thick continuous casting slab. The TMCP technology with controlled rolling and controlled cooling is adopted. The two stage controlled rolling fully guarantee the deformation amount of recrystallization area. After rolling, the phase change structure was ensured by accelerated cooling. With the best combination of composition and process, high strength and high low temperature impact toughness ABS EH40 steel plates are obtained.

The production process of TMCP ABS EH40 steel plates is as follows: iron water pretreatment, converter smelting, refining outside furnace, continuous casting, slab reheating, control rolling, control cooling and heap cooling.