LI Hua-bing
,
JIANG Zhou-hua
,
FENG Hao
,
MA Qi-feng
,
ZHAN Dong-ping
钢铁研究学报(英文版)
The solution-treated (ST) condition and aging precipitation behavior of 18Cr-16Mn-2Mo-1.1N high nitrogen austenitic stainless steel (HNS) were investigated by optical microscope (OM), scanning electron microscope (SEM), and transmission electron microscope (TEM). The results show that the ST condition of 18Cr-16Mn-2Mo-1.1N HNS with wN above 1% is identified as 1100 ℃ for 90 min, followed by water quenching to make sure the secondary phases completely dissolve into austenitic matrix and prevent the grains coarsening too much. Initial time-temperature-precipitation (TTP) curve of aged 18Cr-16Mn-2Mo-1.1N HNS which starts with precipitation of 0.05% in volume fraction is defined and the “nose” temperature of precipitation is found to be 850 ℃ with an incubation period of 1 min. Hexagonal intergranular and cellular Cr2N with a=0.478 nm and c=0.444 nm precipitates gradually increase in the isothermal aging treatment. The matrix nitrogen depletion due to the intergranular and a few cellular Cr2N precipitates induces the decay of Vickers hardness, and the increment of cellular Cr2N causes the increase in the values. Impact toughness presents a monotonic decrease and SEM morphologies show the leading brittle intergranular fracture. The ultimate tensile strength (UTS), yield strength (YS) and elongation (El) deteriorate obviously. Stress concentration occurs when the matrix dislocations pile up at the interfaces of precipitation and matrix, and the interfacial dislocations may become precursors to the misfit dislocations, which can form small cleavage facets and accelerate the formation of cracks.
关键词:
solution-treated condition
,
aging precipitation behavior
,
time-temperature-precipitation curve
,
high nitrogen austenitic stainless steel
,
mechanical property
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。
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