Q390D steel plate and production method thereof

However, this method needs to add micro-alloys such as Nb, V, Ti, etc., and the cost of the alloy is high

After t...

Ti content is higher in composition design, therefore in production process, continuous casting slab adopts higher heating temperature and longer heating time, when heating like this, Ti in steel can fully solid solution go in, so that rolling When cooling after casting and rolling, the carbon and nitride of Ti can be fully analyzed to improve the structure of the steel plate; the purpose of using a longer heating time in the soaking section is to make the temperature of the continuous casting slab uniform, so that the load of the rolling mill is uniform during rolling. It can achieve a larger single-pass reduction rate, which is beneficial to improve the microstructure of the steel plate. According to the chemical composition and mechanical performance requirements of the steel grade, the heated continuous casting slab is subjected to controlled rolling in the austenite recrystallization zone and non-recrystallization zone. The steel grade adopts two-stage controlled rolling. The first-stage controlled rolling belongs to the austenite recrystallization controlled rolling in the high-temperature zone. This stage adopts a low-speed, high-pressure rolling strategy. Large single-pass reduction rate can fully penetrate the rolling deformation to the center of the steel plate, fully refine the austenite grain and uniform austenite structure, and at the same time, the high-temperature welding produced by rolling largely eliminates the Defects such ...