Smelting production method of titanium microalloyed low-cost Q355B steel plate

The invention discloses a smelting production method of a titanium microalloyed low-cost Q355B steel plate. The method comprises the steps of 1, acquiring raw materials, specifically, low-sulfur and low-phosphorus molten iron is slected; 2, smelting through a converter, specifically, deep dephosphorization is carried out by adopting a double slag smelting process; 3, tapping, specifically, any point blowing operations are avoided at the smelting end point, a silicon-manganese alloy is added for deoxidation during the tapping process, and the slag thickness in a molten steel tank is less than or equal to 40 mm after tapping; 4, carrying out argon station treatment, specifically, after molten steel reaches an argon station, argon bottom blowing is kept, an aluminum wire is fed immediately, the Als content in the molten steel is 0.020%-0.040% after the aluminum wire is fed, argon soft blowing is kept for 2-3 minutes, the fine adjustment of the alloy is completed during the period of the argon soft blowing, and t