提高120t转炉煤气回收量的生产实践

对120t转炉煤气回收量进行了分析,采取降罩吹炼和合理供氧、合理控制炉口微差压、优化转炉煤气回收参数、调整副枪测温时间等措施,转炉煤气回收量由约90m3/t提高到120m3/t,最大日回收量达到126m3/t。     

转炉煤气回收规律及其影响因素研究

分析了转炉炉气成分和发生量随冶炼时间的变化规律 ,研究了转炉煤气回收量与影响因素之间的关系 ,给出了理想工况下的吨钢转炉煤气最大回收量。结果表明 ,铁水比提高1 % ,吨钢煤气回收量提高 1 0 89m3 /t;供氧强度提高 1m3 /(t·min) ,煤气回收量增加1 1 95 5m3 /t;若将煤气回收限制性条件放宽至CO≥ 3 5 %且O2 <1 % ,吨钢回收量提高1 5 2m3 /t;在理想工况下 ,转炉煤气最大回收量为 1 2 8 83m3 /t。     

优化转炉煤气回收的研究与实践

通过对电除尘器、煤气加压机进行升级改造和提高操作水平使煤气含尘量由50mg/m3降低到5mg/m3,回收CO煤气含量由50％提高到62％,煤气回收量由65m3/t提高到89m3/t,既减少了环境环境污染,又取得了显著的经济效益.     

转炉煤气回收量低的原因及解决措施

分析了鞍钢鲅鱼圈钢铁分公司转炉煤气回收量低的主要原因是煤气回收时间短和烟气流量小。从程序控制、操作制度、仪表校准、设备参数调整等方面制定了控制措施,措施实施后,煤气回收量由不足75 m3/t提高到102.7 m3/t。     

全湿法转炉煤气回收净化系统设计改进

通过对全湿法转炉煤气回收净化系统除尘效率影响因素的分析 ,提出了合理设计喷嘴、使用重力除尘器的改造设计方案 ,可使整个系统除尘效率、脱水效率得到提高。分析认为回收的煤气含尘量可小于 10 0mg/m3。部分设计项目改造后吨钢回收煤气由 3 0m3提高到 75m3,年产钢 2 2 0万t ,年创利润可达 13 3万元     

宣钢转炉煤气回收系统优化改造的实践

国内先进的钢铁企业转炉煤气回收量达到120 m3/t钢,宣钢转炉煤气回收量不到60 m3/t钢,为提高宣钢转炉煤气回收量,进行了相应的节能技术改造.     

提高马钢新区转炉煤气回收率的分析与实践

分析、研究了影响马钢新区转炉煤气回收的各类因素,提出了延长回收区间、改善回收操作、优化系统平衡等具体措施。结果表明,部分措施实施后转炉煤气回收率提高3.21 m3/t。     

技术信息

国内·马钢一钢厂实现负能炼钢MINUS ENGERGY CONSUMPTION STEEL MAKINGAT No.1STEEL MAKING SHOP,MAANSHAN STEEL2 0 0 2年 9月 ,马钢一钢厂已回收能量 3 4.0 kg标煤 / t坯、消耗能量 3 3 .4kg标煤 / t坯 ,两者相较负 0 .6kg标煤 / t坯 ,成为继宝钢、武钢之后在全国实现负能炼钢的厂家。一钢厂自 2 0 0 1年 2月 95 t转炉热负荷试车成功之日起就同步实现了转炉煤气和蒸汽回收 ,并把实现负能炼钢作为攻关目标。该厂规范了煤气回收操作 ,修改煤气回收工艺参数 ,延长煤气回收时间 ,开展氧含量超标及高碳钢煤气回收…     

联合特钢转炉煤气回收工艺探索

通过对炼钢厂煤气回收、利用的现状进行分析与研究,找出转炉煤气回收和净化过程中的影响因素。结合炼钢厂目前生产工艺和设备条件,通过采取调整转炉操作、更改喉口开度设定、优化回收条件和加强操作以及设备管理等措施,使煤气回收量由原来的95.79 m3/t提高到135.57 m~3/t,节能效果显著。     

钒钛铁水转炉炼钢煤气回收工艺技术的优化

系统分析了冶炼含钒铁水特殊工艺条件下影响转炉煤气回收的诸多因素。通过工业试验优化了相关工序环节的操作和控制水平,如:调整活动烟罩高度,炉口微压控制,优化炼钢吹炼过程的加料制度,确保转炉煤气的平稳回收,优化造渣制度及氧枪操作方式,修订煤气回收限值等,提高了炼钢工序煤气回收水平。在半钢炼钢条件下转炉煤气回收量达119.87 m3/t,煤气热值达5 578.655 k J/m3。     

海洋平台用钢的研发生产现状与发展趋势

介绍了国内外海洋平台用钢发展现状,总结出海洋平台用钢生产的主要特点,对传统海洋平台用钢的成分、工艺、组织、性能特征及其局限性进行了分析,提出了开发"Mn/C"合金化新型高强韧海洋平台用钢的发展思路,对海洋平台用钢今后的发展趋势加以展望。鉴于我国高级别海洋工程用钢与国外相比仍存在一定的差距,关键产品还依赖于进口,今后应重点研制屈服强度为690 MPa级的海洋平台用高强韧钢。     

Inclusion characterisation – tool for measurement of steel cleanliness and process control: Part 1

Abstract

Owing to increasing demand for high surface and internal quality finished steel products, it is imperative to study the factors that limit the production of such steels. In particular, non-metallic inclusions affect steel cleanliness and cause defects leading to worsening of desired mechanical properties and service life of steel products. Other detrimental effects of inclusions are poor steel castability often resulting in slab downgrades and rejections, increased costs associated with recycling of liquid steel and refractories, and even shut down of the caster. Inclusion engineering is thus important to achieve process and quality control on a daily production basis. This article, in two parts, addresses inclusion characterisation as a tool for understanding and improving process conditions, minimising nozzle clogging and reducing sliver rejections in Ti stabilised ultra low carbon steels, Ca treated low carbon Al killed steels and advanced high strength steels. The paper begins with a survey of techniques followed by examples of use of techniques to resolve steelmaking and casting issues that affect quality of steel. Part I explains the use of an automated scanning electron microscope to correlate inclusion data with industrial process conditions. Examples include effect of different samplers, influence of ferroalloy quality and temperature control practices, ratio of elemental chemistries, ladle stirring etc. on quality of steel.     

国内外易切削钢的现状和研究进展

易切削钢比普通碳素钢有较好的切削性能和更好的产品表面光洁度。随着自动化加工工业和汽车工业的发展,易切削钢的使用量不断增加。目前,国外普遍采用电弧炉二次精炼连铸流程生产易切削钢。工业化国家切削钢已形成标准化系列产品,并伴随连铸技术的广泛采用,使易切削钢具有均匀的切削性能。现有易切削钢种为易切削碳钢、渗碳钢、调质钢和不锈钢,并不断将易切削钢扩展到诸如模具钢、高锰钢、耐热钢、高工钢等钢类。在分析国内外易切削钢发展的基础上,讨论了易切削钢生产工艺、钢种的发展方向。     

残留奥氏体对微纳贝氏体钢塑韧性的影响

采用高碳和中碳低温贝氏体转变工艺（095C钢为200℃等温10d,030C钢为320℃等温1d）研究了残留奥氏体对微纳结构钢塑韧性的影响,对不同试样的显微组织、各相体积分数、伸长率和冲击韧性进行观察、检测和分析。试验结果表明,中碳钢贝氏体转变的塑韧性明显高于高碳钢贝氏体转变,主要原因是中碳钢贝氏体转变中存在一定的亚微米级薄膜状残留奥氏体,在拉伸或冲击过程中引起的残留奥氏体的塑性变形,使断裂的能量增加,可以显著提高样品的塑韧性。     

钛、铌、硼对低碳贝氏体钢组织与性能的影响

以C-Mn钢和700 MPa级低碳贝氏体钢成分为基础成分,通过调整微合金元素含量,实验室条件下熔炼浇注钢锭,并采用TMCP技术轧制钢板,研究了微合金元素钛、铌、硼对低碳贝氏体钢组织与性能的影响。结果表明,随着铌含量的增加,贝氏体含量增加,晶粒变细,材料的抗拉强度、屈服强度与韧性均增加;随着钛含量的增加,贝氏体含量增加,抗拉强度、屈服强度提高,韧性的变化与是否进行回火处理有关;硼有利于形成板条贝氏体组织,硼含量增加能提高强度,但有损韧性。     

Effect of annealing time on solute carbon in ultralow-carbon Ti-V and Ti-Nb steels

The influence of annealing temperature and time on solute carbon levels was investigated in four ultralow-carbon (ULC) bake-hardenable steels; two Ti-V ULC steels with different V/C levels and two Ti-Nb ULC steels with different Nb/C levels. Internal-friction and scanning transmission electron microscopy (STEM) techniques were used to understand the precipitation/dissolution behavior in the various steels. An effect of annealing time on the carbon Snoek-peak height was observed in both Ti-V steels and in the Ti-Nb steel having a lower Nb/C ratio. Despite differences between these steels resulting from their composition (and, thus, carbide solubility) differences, after cold rolling and annealing at different temperatures, the maximum Snoek-peak height was achieved after annealing for shorter times in each instance, on the order of 1 minute. The highly stabilized Ti-Nb ULC steel with a higher Nb/C ratio did not show the effect because of the absence of solute carbon. For the Ti-V steels, most of the precipitates examined using STEM contained both Ti and V. The energy-dispersive X-ray (EDX) analysis indicated that both the Ti-V steels annealed at 845 °C for 1 minute have greater Ti/V ratios compared to their corresponding Ti-V steels in the as-received (hot-rolled) condition. This behavior is consistent with dissolution of carbides causing the carbon in solution to increase, as indicated by a greater carbon Snoek-peak height for both Ti-V steels in the annealed condition. The reduction in Snoek-peak height at longer annealing times is believed to be associated with segregation to lower-energy defect sites.     

碳素结构钢、低合金高强度结构钢标准新旧牌号对比

碳素结构钢和低合金钢占钢产量的７５％以上,由于新旧标准在牌号表示方法上不一致。不少同志反映新旧牌号的定义及表示上不易理解,为此作如下说明与对比。     

高强度螺栓钢的开发与应用

文中介绍了低合金钢、含硼钢和非调质钢等螺栓钢的性能和应用，以及近期高强度螺栓钢的开发。     

Hydrogen Diffusion and Trapping Effects in Low and Medium Carbon Steels for Subsurface Reinforcement in the Proposed Yucca Mountain Repository

The electrochemical hydrogen permeation method was used to investigate hydrogen transport, trapping characteristics of low (0.08 pct C) and medium carbon (0.44 pct C) steels proposed for the Yucca Mountain (YM) repository environment. The presence of relatively high amounts of C, Mn, and S increased the density of trapping sites in medium carbon steel. The measured diffusivity of medium carbon steel was lower than that of the low carbon steel due to increased trapping of hydrogen at irreversible sites in the medium carbon steel. Hydrogen concentration values obtained for low carbon steels in YM ground water electrolytes indicate that increased ionic concentration decreases the uptake of hydrogen. The decrease in hydrogen permeation were due the formation of CaCO₃ corrosion products on the surface of steels.     

Recent Development of Air-Cooled Bainitic Steels Containing Manganese

The superiorities of air-cooled bainitic steels were described. A series of air-cooled bainitic steels containing manganese were developed and presented, which include low carbon granular bainitic steels, low carbon grain-boundary allotriomorphic ferrite/granular bainite dual phase steels, medium and medium high carbon bainite/martensite dual phase steel, low carbon carbide free bainite/martensite dual phase steels and casting bainitic steels.The development of ultra-low carbon bainitic steels in China was also introduced.