FENG Chun
,
FANG Hong-sheng
钢铁研究学报(英文版)
A new hot-rolled low carbon air-cooling bainitic steel containing 0.02%Nb has been developed based on alloying design of the grain boundary allotriomorphic ferrite (FGBA)/ granular bainite (BG) duplex steel.The as-rolled microstructure and mechanical properties of 0.02%Nb bainitic steel were investigated by tensile test, X-ray diffraction(XRD),Optical Microscopy (OM), scanning electron microscopy (SEM) ,and Transmission electron microscopy(TEM). The results show that (1) The addition of 0.02% niobium improves the strength obviously without sacrificing toughness of the FGBA/BG steel. Compared with Non-Nb FGBA/ BG steel, 0.02% Nb increases the tensile strength and yield strength about 20% (From 780Mpa to 937Mpa)and 17%(From 557Mpa to 650Mpa) respectively, remaining 18% elongation and 83J Akv. (2) Small addition of Nb(0.02%) not only refines the allotriomorphic ferrite grain but also promotes the nucleation of intragranular ferrite, both of which in turn contribute to the refinement of granular bainite cluster including its ferrite platelets and M-A islands. Compared with Non-Nb steel, the volume fraction of M-A island in 0.02%Nb steel increases from 21% to 31%, and the average size of M-A island decreases from 1.2μm to 0.95um.(3)There is hardly any Nb(C,N) has been observed in 0.02%Nb steel. It is suggested that the strengthening effect of 0.02%Nb can be mainly attributed to the influence of the segregation of Nb to γ/α phase boundaries(solute drag-like effect) on the phase transformation rather than the precipitation strengthening of Nb(C,N).
关键词:
Low carbon air cooling bainitic steel;Small addition of Nb;Microstructure;Mechanical properties
FANG Hongsheng
,
FENG Chun
,
ZHENG Yankang
,
YANG Zhigang
,
BAI Bingzhe
钢铁研究学报(英文版)
The development and mechanical performances of new type aircooled Mn series bainitic steels including granular bainitic steels, FGBA/BG duplex steels, CFB/M duplex steels, medium carbon bainite/martensite steels, cast bainitic steels invented by the authors are summarized. The novel series of bainitic steels are alloyed with Mn, and several series bainitic duplex microstructures can be easily obtained under the condition of air cooling through unique composition design. The invented idea, the principle of alloying design, the strengthening mechanism, and the evolution of the microstructure of new type aircooled Mn series bainitic steels are presented. Furthermore, the applications in different fields of these Mn series aircooled bainitic steels with different strength level are also introduced. It is suggested that the significance of the development of the aircooled Mn series bainitic steel can be summarized as follows: reducing costs of both raw materials and production; good combination of strength and toughness; selfhardening with high bainitic hardenability by air cooling from hot working without additional quenchingtempering treatment or quenching procedure; large savings in energy resources; and reduced environmental pollution.
关键词:
bainite;bainitic steel;microstructure;mechanical property;air cooling
李凤娟
,
吕国光
金属世界
doi:10.3969/j.issn.1000-6826.2014.04.14
通过对烧结配料所需原料及对冷烧结矿成品检验采制样方法的分析，找出影响检验结果真实性的因素，采取有效的改进措施，使本钢原料厂一次配料、本钢炼铁厂265 m2烧结二次配料及265 m2烧结系统各项稳定率有了很大的提高，烧结矿实物质量和各项技术质量指标有了很大的进步，保证了高炉的稳定顺行。
提高本钢265 m2冷烧结矿及原料检验代表性的实践
Practice of Improving the 265 m2 Cold Sinter and Raw Material Inspection Representative
供稿|
李凤娟,吕国光/
LI Feng-juan, LV Guo-guang
DOI：10.3969/j.issn.1000-6826.2014.04.14
导读内容
本钢炼铁厂265 m2烧结机生产所需要的含铁原料比较复杂，一次配料料种较多，且烧结含铁原料是由本钢原料厂二车间供料，原料质量的不稳定，会影响烧结矿质量的提高和新一号高炉的强化及高炉技术指标的改善。本钢质量管理中心驻冷烧检查站加强了对烧结配料所需原料及对冷烧结矿成品检验采制样代表性的研究，采取了一些改进措施，达到了良好的效果。含铁料成分稳定率、烧结矿各项质量和技术指标在稳步地提高。下面，对本钢质量管理中心驻冷烧检查站就提高采样及检验过程的准确性所采取的措施和办法进行说明。
烧结矿采样是半自动采样，每两小时采样一次，作为一个批次，来代表整个2h烧结矿的成份。
关键词:
