薄板坯连铸连轧工艺含Ti钢铸坯中的成分偏析

分析了CSP工艺条件下低碳含Ti钢铸坯中Mn、Ti两种元素的分布情况,发现了比较明显的微观偏析现象;通过比较发现,CSP铸坯的成分偏析比传统铸坯中的偏析小得多.     

Evolution of inclusions in a pipeline steel during continuous casting and hot rolling process

Industrial trials were performed to study the evolution of inclusions in a pipeline steel during the continuous casting and hot rolling process.The main composi...     

表面温度波动对微合金钢连铸板坯热塑性的影响

由于铸坯表面与二冷辊列夹持辊发生的间断式接触传热,其表面温度存在一定程度的上下波动.基于J55微合金钢,考虑温度波动的影响,研究了钢在不同热状态下的热塑性.结果表明,高于850℃时温度波动制度下测得的断面收缩率低于常规恒温制度下的测量值,而等于或低于850℃时情况相反.分析了两种不同温度制度下测试结果的差异,认为对于微合金钢,存在着略高于所测钢种Ae₃温度的某一分界温度,高于该温度时恒温制度下测得的塑性值相比波动制度下塑性值偏高,而低于该温度时则偏低.这一认识有助于更加合理地制定实际连铸过程的矫直温度.     

棒材连铸小方坯冷热混装加热工艺实践

针对连铸小方坯冷热混装加热工艺 ,造成加热炉能耗及钢的氧化烧损增加问题 ,提出了在生产实践中采取的技术措施 ,以节约煤气消耗 ,减少氧化烧损 ,提高成材率。     

Controlled rolling of high-strength microalloyed pipe steel on a 5000 thick-sheet mill

Models are developed to describe and predict the geometric and temperature conditions of thick-sheet rolling at different stages (with determination of the billet parameters, its chemical composition, and also the conditions of heating, rough and final rolling, and accelerated cooling). On that basis, effective production conditions for pipe blanks of strength classes K60 and X80 are formulated, so as to ensure the required structural state and specified mechanical properties of the blank.     

微合金钢薄板坯连铸边角裂纹控制

微合金钢薄板坯连铸过程高发边角部裂纹,致使热轧卷板边部产生翘皮、烂边等质量缺陷,是钢铁行业的共性技术难题。本文立足于某钢厂QStE380TM低碳含铌钛微合金钢薄板坯连铸生产,检测分析了铸坯角部组织金相结构与碳氮化物析出特点、不同冷却与变形速率条件下钢的断面收缩率,并数值仿真研究了不同结构结晶器和二冷区铸坯温度与应力的演变规律。结果表明:微合金钢薄板坯连铸过程存在明显的第三脆性区,且变形速率越大,第三脆性区越显著。传统薄板坯连铸工艺条件下,结晶器的中上部及其出口至液芯压下段的二冷高温区,铸坯角部冷速较低,致使其组织晶界含铌钛微合金碳氮化物呈链状析出。铸坯在液芯压下过程,低塑性角部因受较大变形与应力作用而引发裂纹缺陷。实施沿高度方向有效补偿坯壳凝固收缩的窄面高斯凹型曲面结晶器及其足辊区超强冷工艺,可分别提升铸坯角部冷速至10和20 ℃·s?1以上,从而促使铸坯角部组织碳氮化物弥散析出,并促进铸坯窄面在液芯压下过程金属宽展流动而降低角部压下应力,大幅降低了微合金钢薄板坯边角部裂纹发生率。      

High-temperature plasticity of microalloyed steel

The influence of continuous casting of steel on the high-temperature plasticity of microalloyed steel is investigated. The Gleeble-3800 system is used for the physical modeling of the steel’s hot plasticity. The temperature ranges of plasticity are determined in different conditions of slab cooling in the continuouscasting machine. In all the simulations, a trough is seen on the temperature dependence of the steel’s plasticity. With enlargement of the grain boundaries (decrease in grain size), the high-temperature plasticity increases.     

炼钢-连铸-热轧一体化管理

炼钢－连铸－热轧作为钢铁生产流程中的三大关键工序，它们之间不仅存在物流平衡和资源平衡问题，而且存在能量平衡和时间平衡问题。为了节省能源、减少烧损、缩短生产周期，国外钢铁企业十分关注它们的一体化管理。结合我国具体情况，对炼钢－连铸－热轧一体化管理的内容、意义、条件以及国外情况进行了系统的阐述。     

Improving the plasticity of hard-to-work tool steel in continuous casting

Pulsed-continuous melt solidification is developed for the production of chill-cast ingots and continuous-cast billets of hard-to-work P6M5 steel. The introduction of pulsed-continuous melt solidification and linear-solidification heat treatment at OAO MMZ Serp i Molot has permitted the continuous casting of high-speed P6M5 steel on a radial machine (radius of curvature 9 m). The new method produces continuous-cast billets of increased plasticity, thereby eliminating the need for forging. The new system has been used to produce hot- and cold-rolled P6M5 steel sheet and bar.     

常规热连轧线Ti-IF钢铁素体轧制工艺研究与应用

 介绍了铁素体区轧制技术的优势、特点以及其在国内外钢铁企业的发展情况,重点阐述了Ti-IF钢铁素体轧制工艺在常规热连轧生产线上的成功开发与应用,结合常规热轧产线的装备特点进行工艺制度与成分体系的分析与设计,掌握了铁素体轧制板材产品的工艺控制过程和方法,同时针对生产Ti-IF钢铁素体轧制的润滑条件对{111}织构强度的影响进行了对比分析和改进,实现了1 100 ℃的低温轧制技术,达到了提高轧线成材率、节能降耗的目的,并从产品开发及用户使用角度出发,为铁素体轧制高性能产品推广提供了技术保证。     

IF钢连铸坯及热轧板夹杂物研究

夹杂物是影响IF钢表面质量的重要因素。对某厂生产的IF钢连铸坯和热轧板取样, 采用光学显微镜、扫描电镜、能谱、大样电解等多种检测分析方法, 分析了夹杂物的形貌、尺寸、数量、分布以及成分等。研究发现, 热轧工艺的轧制作用使连铸坯宽度方向1/4处聚集的夹杂物向边部迁移, 最终造成热轧板边部夹杂物指数最高, 说明夹杂物聚集带在轧制过程中具有遗传性。热轧板中20 μm以下夹杂所占百分比与连铸坯中夹杂相比稍有增大, 50 μm以上夹杂所占百分比稍有降低。热轧工艺的轧制作用将连铸坯中大颗粒氧化铝夹杂挤压变形为热轧板中的长条状, 容易形成表面条状缺陷。夹杂物在连铸坯距内弧侧30 mm处存在聚集现象, 热轧板中距内弧侧0.5 mm处夹杂物指数最高, 这是由于等效应变不同使夹杂物聚集带向表层迁移。IF钢连铸坯和热轧板中主要有4类显微夹杂, 分别为Al₂O₃类、TiN、Al₂O₃-TiO_x和SiO₂类复合夹杂, 且两者中各类夹杂物所占百分比差别不大。      

基于生产流程的炼钢-连铸-热轧仿真系统

介绍了基于生产流程的炼钢-连铸-热轧仿真系统,该系统利用系统建模、仿真技术,采用分布式结构,模拟钢铁生产过程。仿真工位涉及转炉、电炉、LF炉、RH炉、VOD炉、AOD炉、LATS炉、连铸和轧钢。系统根据作业生产计划组织生产、监视生产过程,并对结果进行分析。该系统建立了钢铁生产流程的框架,为生产过程的研究提供了研究工具,为相关应用系统的开发提供了调试验证的环境。     

连铸与热轧工序余材集成匹配模型与算法

针对钢铁企业连铸工序余材板坯及热轧工序余材钢卷对热轧生产合同的匹配问题,基于一体化的管理思想建立了余材板坯、钢卷与合同集成匹配的多目标0-1非线性整数规划模型,在模型中引入板坯材质与合同要求钢种特征差异值矩阵及钢卷钢种与合同要求钢种特征差异值矩阵.采用分段整数编码、基于启发式修复策略的改进遗传算法求解.最后,通过对实际生产数据的仿真实验验证了所提模型和算法的有效性,为科学合理地匹配铸轧工序余材板坯、钢卷提供了有效的解决方法.     

高碳钢连铸钢液过热度的控制

阐述在一炼钢条件下生产高碳钢时浇铸温度的控制措施。通过改善钢包、中包的保温效果,并采用合理的LF炉温度控制模式,可以使高碳钢在进行低拉速浇铸时获得稳定且较低的过热度,从而有效降低铸坯碳偏析。     

胀断连杆用高碳微合金钢连铸大方坯的铸态组织

胀断连杆是汽车精密传动用高端产品,需具高强高韧和裂解加工脆性解理断裂特性。连铸化生产高碳易切削胀断连杆用微合金非调质钢是当前的发展方向。基于大方坯连铸生产典型工艺及其铸态组织、成分均匀性分析,研究了胀断连杆加工过程常见断口形貌不合的钢坯遗传性因素。以常用德系C70S6钢为例,采用250 mm×280 mm断面弧形连铸机,解析其在一定结晶器电磁搅拌条件下所浇铸大方坯的铸态低倍结构和枝晶形貌,并分析其不同晶区的成分分布特点。结果表明,当前连铸条件下大方坯中心缩孔和后续热轧棒材探伤合格率可控,但铸坯初凝坯壳凝固前沿发生明显的C、S负偏析白亮带区及其柱状晶偏转现象。金相试样图像分析和相场法凝固模拟表明,铸坯中柱状晶具有逆流生长特征,其偏转角是一次枝晶尖端向旋流方向逆向生长的结果。自铸坯角部至宽、窄面中心,实测柱状晶区的一次枝晶偏转角约在?7°到27°之间。利用X射线能谱分析（EDS）进一步检测了钢中主要合金元素Si、Mn、Mo在铸坯不同晶区的分布,揭示了其铸态偏析特征与差异性。据此,探讨了这种铸态组织和成分偏析对后续热轧棒材和连杆成品组织的遗传性,以及对其胀断加工断口不合的影响,可为源头铸态质量的控制提供依据。      

两流方式下薄板坯连铸连轧生产组织方法及仿真

针对薄板坯连铸连轧两流供料方式下生产组织中出现的新问题,提出两种生产计划组织方式,建立模型进行仿真分析.根据仿真分析结果对薄板坯连铸连轧的生产组织方式选择提出建议.     

Hot ductility trough elimination through single cycle of intense cooling and reheating for microalloyed steel casting

Surface transverse cracking, especially corner cracking, is prone to generate in continuously cast slabs of microalloyed steels. The method of surface structure control (SSC) was supposed to the best way to avoid the detrimental defects. However, the mechanism of improving hot ductility by SSC and the specific parameters to control the process are still unclear for the reasonable adoption in production. In the present work, the impact of cooling rate, holding temperature and holding time on austenite decomposition, and the austenite grain size before and after intense cooling were investigated by thermal simulation method. With the increase of cooling rate, it is observed that the phase is transformed from austenite?→?grain boundary film-like alltromorph ferrite?→?Widmanstätten ferrite plates (or intragranular ferrite plates)?→?bainite+martensite. Mostly important, the film-like ferrite can be eliminated through intense cooling and the following reheating, but the austenite grain size is not observed to be refined through the single γ?→?α?→?γ cycle. Even though, the reduction of area (RA) is improved drastically to over 70% in the third ductility trough, whereas the RA value is just 相似文献   

连铸—连轧自动化

叙述了连铸-连轧自动化所需解决的几个关键问题及此自动化技术的新进展，并给出了建议的系统结构。     

Reduced metal consumption in hot pipe rolling

Means of reducing the metal consumption in the hot rolling of seamless pipe are considered. The most common is the use of square or round continuous-cast billet. The trimming required for Pilger mills may be reduced by preparation of the front ends of the sleeves in skew rolling and rolling of the rear end at the free section of the mandrel. To expand the range of pipe to D/S = 15–30 for the 200 system with a three-roller mill, grooves created with special liners in the gaps between the rollers have been adopted at OAO Interpipe Nizhnedneprovskii Truboprokatnyi Zavod. In addition, the wall thickness is regulated by means of a hydromechanical clamp.