浅析宝钢厚板成品氮的控制

Analysis of nitrogen control on producing heavy plate in Baosteel

分析了氮在钢水中的行为以及氮在厚板中的危害,介绍了转炉、精炼、连铸生产过程中采取的主要技术措施,包括转炉提高铁水比、优化合金加入方式;LF精炼炉气氛控制、造好白渣、埋弧操作;充分利用RH脱氮功能降低钢水中的氮,防止增氮;钢包长水口及氩封保护浇铸,防止连铸过程钢液吸氮。通过以上措施,厚板产品中的氮含量较以前有了显著的下降,厚板板坯的裂纹得到明显改善。

Behavior of nitrogen in steel was analyzed and the hazard of nitrogen in heavy plate was also explained.The main technological measures about converter,refining,casting were introduced.The measures included higher hot metal ratio,optimizing alloying,atmosphere controlling and formation of good white slag and submerged arc operation in LF,removing nitrogen in steel by degassing of RH,preventing against nitrogen into steel in RH,and adoption of long nozzle and argon sealing between ladle and tundish to prevent against nitrogen pick-up in continuous casting.The content of nitrogen in heavy plate was significantly lowered with a series of measures adopted.The crack on casting slab was greatly improved by reducing the content of nitrogen in heavy plate.