耐火耐候抗震高层建筑用Q460GJNHFREZ35特厚板的研制

Development of Q460GJNHFREZ35 heavy plate for fire-resistant,weathering and anti-seismic high-rise building

针对我国亟需开发耐火耐候抗震高层建筑用钢板的现状,南阳汉冶特钢公司对Q460GJNHFREZ35特厚板化学成分进行了设计,满足了碳当量、焊接裂纹敏感性指数、耐候系数等条件的要求;通过水冷铜板结晶器锭模浇铸、采用0.25~0.60变形系数的"高温、低速、大压下"工艺及差温轧制工艺,保证了100~300 mm特厚板心部组织的致密性并为获得良好的低温冲击韧性提供了条件;轧后采用淬火+亚温淬火+回火的热处理工艺,获得了以贝氏体+铁素体为主的均匀组织,实现了软硬相的结合,满足了高强度和高韧性、屈强比不大于0.83,以及600℃保持1~3 h后强度不低于室温强度2/3的耐火性能要求。

In view of the current situation that China urgently needs to develop plates for fire-resistant,weathering and earthquake resistant high-rise buildings,the chemical composition of Q460 GJNHFREZ35 heavy plate was designed in Nanyang Hanye Special Steel Company,which meets the requirements of carbon equivalent,welding crack sensitivity index,weathering coefficient and so on.Through applying the ingot mold casting of water-cooled copper plate crystallizer,the"high temperature,low speed,large reduction"with deformation coefficient of 0.25-0.60 and differential temperature rolling process,the compactness of the core structure of 100-300 mm thickness heavy plate was ensured,and good low temperature impact toughness was provided.After rolling,the heat treatment processes of quenching+intercritical quenching+tempering were adopted to obtain a uniform structure dominated by bainite+ferrite,the microstructure combination of soft phase and hard phase was realized,and the high strength and high toughness,yield ratio not greater than 0.83,and strength not less than 2/3 of room temperature strength after being maintained at 600℃for 1-3 hours were obtained,which met the performance requirements.