1. The steelmaking process: using the practice process combining electric furnace + LF furnace. During the VD vacuum treatment, ensure that the vacuum is ≤66Pa, and the vacuum is maintained for 20-25 minutes, and then the steel ingot is broken.
2. In the heating process, the steel ingot is heated in a soaking furnace, the highest heating temperature is 1270, and the temperature of the soaking section is 1250 - 1260, to ensure that the surface and the inside of the ingot are heated evenly.
3. Normalizing process, the S355J2 steel plate is normalized in the bottom of the furnace, the steel plate normalizing temperature is 880-910, and the holding time is 1.8-2.2 min/mm, and the required S355J2+N-Z35 steel plate is obtained.
