摘要
针对热轧厚钢板、管型材等产品在高温轧制或焊接条件下组织难以均匀细化的共性问题,开展了基础理论-关键技术-产品工艺的系统研究,通过对已有技术的发展和探索创新,提出基于析出相控制的新型本质细晶钢技术路线。通过“冶炼→连铸→轧制→冷却→焊接”全流程一体化工艺控制,调控钢中高热稳定性微-纳米析出相粒子分布,结合加工工艺优化控制,促进基体和焊接组织均匀细化,突破传统组织性能调控手段及工艺条件限制,显著提升材料综合服役性能,推动实现先进钢材的高性能绿色化制造。采用热力学计算软件分析了低合金钢中部分氮化物和氧化物的析出规律,利用电子探针显微镜和扫描电镜表征了钢中典型高温析出相的结构特征,从析出物的热稳定性及其与基体的交互作用角度说明复合析出相的设计思路。讨论了第二相诱导晶内铁素体形核的贫锰区机制和共格界面机制,采用高温原位表征技术研究了晶内铁素体转变行为,阐述了基于多类型、多尺度复合析出相体系设计的晶界、晶内多重组织细化机制。技术应用于大线能量焊接用钢板、热轧结构钢高温高效轧制、热轧无缝钢管在线组织调控、低成本热轧抗震钢筋等产品和工艺的开发,取得良好应用效果,并在更多产品领域展现出广阔的应用前景。
Aiming at microstructure refinement problems in steel plates,tubes and profiles under hot-rolling or welding conditions,a systematic study of theory-technology-product was carried out.Through the development of existing technology and innovation,a new type intrinsically fine-grained steel technology based on precipitation control was proposed.Through the whole process control of smelting-casting-rolling-cooling-welding,distribution of thermostable micro-nano particles in steel was regulated.In combination with optimized process,the matrix and welding microstructure was uniformly refined.It broke through the limitation in microstructure control methods and process conditions,improved the comprehensive performance,and promoted green manufacturing of advanced steels.The precipitation laws of some nitride and oxide were analyzed using thermodynamics calculation software.Typical precipitation particles were characterized with an electron probe micro-analyzer(EPMA)and a scanning electron microscope(SEM).The design concept of composite precipitates was explained from the perspective of thermal stability and their interaction with the matrix.Mn-depletion zone and coherent interface mechanism for particle-induced ferrite nucleation was discussed.Transformation behavior of intragranular ferrite was studied using high-temperature in-situ characterization technology.The multiple microstructure refinement mechanism based on multi-type and multi-scale precipitation system was elaborated.The technology has been applied to high heat input welding steel,efficient hot-rolling of structural steel,hot-rolled seamless steel tubes and low-cost hot-rolled ribbed bars.The technology has achieved good results and demonstrates a broad application prospect in more product fields.
作者
王超
袁国
王国栋
WANG Chao;YUAN Guo;WANG Guodong(The State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 110819,Liaoning,China)
出处
《钢铁》
CAS
CSCD
北大核心
2023年第9期167-177,共11页
Iron and Steel
基金
国家自然科学基金资助项目(U21A20116)。
关键词
本质细晶钢
析出相
晶内铁素体
组织细化
高温变形
大线能量焊接
intrinsically fine-grained steel
precipitation
intragranular ferrite
microstructure refinement
high-temperature deformation
high heat input welding
