Smelting and continuous casting method for high cr-si alloyed hot-formed steel

A smelting and continuous casting method for high Cr—Si alloyed hot-formed steel, wherein the hot-formed steel comprises the following components:

• 0.15-0.35% of C, 0.8-3.2% of Mn, 0.8-2.8% of Si, less than 0.01% of S, less than 0.015% of P, 0.01-0.05% of Al, and 1.5-3.9% of Cr;
• the smelting and continuous casting method comprises the following steps:
• Step 1, preparation before tapping:
• performing converter steelmaking, adding no alloy elements during the converter steelmaking, after completing the converter steelmaking, moving a ladle to a position below a converter, opening the ladle, performing bottom argon blowing in the ladle, performing the bottom argon blowing during an entire period of the tapping, and completely stopping the bottom argon blowing in the ladle until slag dart deployment or confirmation of a slag-free condition during the tapping;
• Step 2, primary alloying:
• starting tapping, and during the tapping, performing converter deoxidation and alloying by sequentially adding a deoxidizer, aluminum balls/aluminum particles, silicon alloys, manganese alloys and chromium alloys, wherein materials for the deoxidation and alloying are added in batches along with a liquid steel flow, after the primary alloying, full alloying of Al is completed and partial alloying of Si, Mn and Cr is completed;
• Step 3, top slag modification:
• after tapping from the converter, adding lime and atop slag modifier to the ladle to perform the top slag modification;
• Step 4, secondary alloying:
• performing an LF refining process, and during the LF refining process, adding the silicon alloys, the manganese alloys and the chromium alloys for the secondary alloying to complete alloying requirements for the remaining elements of Si, Mn and Cr;
• and
• Step 5, alloy trimming:
• performing the alloy trimming, and performing carbon alloying on the basis of changes in carbon in the steel to complete an alloy smelting process.