New Non-Heat-Treatment Manufacturing Concept “TPCP” of Invariable Microstructural Control Integrated with Precipitation Strengthening for High Strength Steel Products

The Thermo-Mechanical Control Process is well known as the process for manufacturing high strength non-heat treated steel with excellent low temperature toughness and weldability. However, in the TMCP process, there exists limits in strength and thickness ranges due to large cooling rate dependency. Authors proposed the Thermo-mechanical Precipitation Control Process with the new concept of combining cooling rate insensitive bainite microstructures with extremely low carbon content and precipitation hardening. The TMCP process is applied to manufacturing of shapes and bars as well as heavy plate, and total production is exceeding 1000 tons.