正火轧制及后续正火工艺对S460NL高强度低温结构钢组织性能的影响

Effect of normalizing rolling and subsequent normalizing process on microstructure and properties of S460NL high-strength low-temperature structural steel

以EN10025-3标准为基本依据,采用中碳、低磷、低硫、低氮、低氢设计了正火高强度低温S460NL结构钢板的成分,通过高均质冶炼连铸工艺,生产了不同规格的正火轧制和正火轧制+正火钢板。结果表明,对于规格60 mm以下S460NL钢板,正火轧制工艺可以满足EN10025-3和EN10164 Z35标准性能要求,对于规格60 mm及以上S460NL钢板,需要增加正火工艺才能满足EN10025-3和EN10164 Z35标准的性能要求;正火轧制+正火态S460NL钢板经PWHT模拟焊热处理后的拉伸性能、-50℃冲击性能优异,符合标准要求。

Based on EN10025-3 standard,the chemical composition of the normalized high-strength low-temperature structural steel S460NL was designed with medium carbon,low phosphorus,sulfur,nitrogen and hydrogen;then through high-homogeneous smelting and continuous casting process,the steel plates with different specifications were produced respectively by normalizing rolling and by normalizing rolling+normalizing.The results show that the steel plates by normalizing rolling process can meet the performance requirements of EN10025-3 standard and EN10164 Z35 standard for the S460NL steel plates with specifications below 60 mm,while for that 60 mm and above,additional normalizing process is required to meet such performance requirements.The normalizing-rolled+normalized S460NL steel plates have excellent tensile properties and excellent impact properties at-50℃ after PWHT simulated post welding heat treatment,which meets the standard requirements.