S355J2 material is a European standard structural steel, mainly used in large machinery manufacturing, equipment bases, large welded steel structures, construction, bridges and other fields. With the continuous development of the economy and the demand for large-scale equipment, the demand for ultra-thick structural steel plates has gradually increased, and the technology of steel plates has become more and more stringent. At the same time, the added value of S355J2 carbon steel plates has been relatively high, especially for the production of ultra-thick steel plates. Realize the production of ultra-thick steel plates. The grain distribution during the rolling process of steel ingot production is uniform, eliminating defects such as porosity and shrinkage inside the steel plate, satisfying the good matching of strength and impact toughness, and the thickness direction performance is better, suitable for mass production.
S355J2 steel plates production
The production method includes steel making, heating, rolling and normalizing processes; the steel rolling process adopts a controlled rolling process. Rolling process, the ingot rolling temperature is 1000 ～ 1050; the first stage adopts the low-speed and high-reduction rolling process, the high-temperature stage is 950 ～ 1000, the rolling speed is 1.6 ～ 2.0m / s, and the single-pass reduction rate is 15 ～ 20%, cumulative The reduction ratio is 40 to 45% to ensure sufficient deformation of the steel ingot. The first stage rolling temperature is 910 ～ 930, and the final rolling temperature is ≤870. 1. The steelmaking process is described by the smelting process combining electric furnace + LF furnace. The vacuum degree during VD vacuum processing is ≤66Pa, and the vacuum holding time is 20-25min. After being broken, the steel ingot is made. 2. In the heating process, the steel ingot is heated in a soaking furnace, the maximum heating temperature is 1270, and the temperature of the soaking section is 1250-1260, ensuring that the steel ingot is heated evenly inside and outside. 3. Normalizing process, the steel plate is normalized in the hearth furnace, the normalizing temperature of the steel plate is 880 ～ 910, and the holding time is 1.8 ～ 2.2min / mm, and the required S355J2 + N-Z35 steel plate is obtained.
