低合金钢宽厚铸坯直装工艺研究  

Research on direct charging of low alloy steel wide-thick slab

作　　者：康伟[1] 方恩俊 李超 于赋志[1] 张宁[1] 廖相巍[1] 

机构地区：[1]鞍钢股份有限公司技术中心冶金工艺所,辽宁鞍山114009 [2]鲅鱼圈分公司炼钢部,辽宁营口115007

出　　处：《炼钢》2014年第6期57-61,共5页Steelmaking

摘　　要：为实现低合金钢宽厚铸坯的直装轧制,结合生产实际,选取Q345B钢为代表钢种,以入炉前铸坯表面温度为参数,分3个温度区域进行直装工艺研究,结果发现低温区和高温区直装轧制钢板裂纹较少,中温区直装轧板裂纹的较多,这是由于γ晶界析出的先共析铁素体(α相)网膜造成;对低温区直装轧制钢板冷弯裂纹进行了检验分析,发现钢板内带状组织、MnS夹杂是产生裂纹的重要原因;分析铸坯金相组织控制、夹杂物控制、析出物控制对直装轧制钢板质量的影响,直装工艺要避免铸坯的金相组织进入两相区,避免γ晶界析出先共析铁素体(α相)网膜,生产中应尽可能降低硫含量或添加一定量的稀土元素以改变MnS夹杂的存在状态,调整微合金元素含量,以保证充分发挥微合金元素的强化作用。For the development of direct charging on low alloy steel, Q345B steel was chosen for direct charging study, three regions were divided according to the tempera- ture on the slab surface , found that surface crack less when direct charging in low and high temperature zone, more found in moderate zone, the thin ferrite layers around aus- tenite grain boundary is the prime reason; analysis of cold bending crack on the direct charging plate in the low temperature zone, the results show that band structure and MnS inclusion are the main reason; analysis the effect of microstructure, inclusions, precipitates to the quality of direct charging plate, concludes that direct charging process must avoid the two-phase region （austenite and ferrite）, avoid the formation of thin fer- rite layers, reduce the sulfur content or adding a certain amount of RE for modifying the shape of MnS inclusions, adjust the content of micro-alloying elements in order to guar- antee the strengthening effect.

关 键 词：低合金钢直装 直装裂纹 金相组织 夹杂物 析出物 

分 类 号：TF777[冶金工程—钢铁冶金]