On July 1, 2025, Baosteel Desheng Stainless Steel Co., Ltd. successfully applied for a patent titled "A Method for Measuring Line Scale Defects in BN4 Stainless Steel Hot Rolled Coils", with application publication number CN120230954A and application date February 28, 2025.

The invention discloses a method for reducing scale defects in BN4 stainless steel hot-rolled coils and its manufacturing method, comprising the following steps: 1) batching; 2) Smelting, the smelting process adopts the double slag method for slag making, and the Si in the reduction stage is controlled between 0.20% and 0.50%, while the aluminum content in the steel is controlled to be ≤ 0.0030%. In the LF furnace refining stage, the slag alkalinity is adjusted to the range of 1.6% to 1.8%; 3) Continuous casting: Control the casting superheat to 25 ℃~35 ℃, and the casting speed of the continuous casting machine is 1.0m/min~1.2m/min; The temperature of the middle package is 1460-1470 ℃; The thickness of the protective slag layer in the crystallizer during casting is 8mm to 13mm; 4) Hot rolling: Send the cast billet obtained in step 3) to the hot rolling heating furnace for insulation; The preheating section has a temperature range of 750 ℃ to 850 ℃, the first heating section has a temperature range of 1060 ℃ to 1100 ℃, and the second heating section has a temperature range of 1200 ℃ to 1210 ℃; The total heating time inside the furnace is 190-230 minutes; The drawing temperature is 1195-1210 ℃. The interlocking steps ultimately reduced the wire scale defect rate of BN4 stainless steel hot-rolled coils from 20% to 30% to within 3%.