IF钢热轧轧制稳定性分析及控制方向

采集热轧实际生产中IF钢轧制过程奥氏体单相区轧制与两相区轧制的各机架轧制温度、轧制力参数,与轧制模型预报结果进行对比分析,明确了IF钢热轧精轧过程中奥氏体、铁素体相变区域以及影响模型轧制力预报的主要因素,提出了轧制过程中厚度波动、板形异常的解决方向。     

中低牌号无取向电工钢轧制工艺研究

热轧轧制工艺对产品性能和轧制稳定性影响很大,对中低牌号无取向电工钢,当在两相区轧制时,热轧塑性明显降低,板形变坏,易出现边裂等情况.以50W1000为例,通过对其变形抗力进行研究,得出把两相区控制在F4与F5之间为最佳轧制工艺的结论.在此基础上制定了一套较为合理的热轧工艺制度.采用新的轧制工艺后,50W1000热轧精轧...     

铁素体SUS430粗轧模型优化与完善

根据铁素体SUS430的加热及变形特点,结合1 780 mm热轧生产线特点,重点从粗轧工艺模型方面介绍了优化粗轧轧制道次及提高宽度控制精度两方面内容：通过减少粗轧道次,缩短粗轧轧制时间,提高精轧开轧温度,以提高热轧产能;另外,在铁素体SUS430坯料宽度波动比较大的前提下,通过优化热轧宽度模型控制参数来提高带钢的宽度控制精度。结果表明对原有不锈钢430轧制工艺的优化与完善,进一步提高了不锈钢430的产能及产品质量。     

唐钢超薄热轧带钢生产线的质量控制技术

介绍了唐钢FTSR超薄热轧带钢生产线的工艺流程,以及代表其技术特色的H^2结晶器、动态液芯压下、动态PC控制、半无头轧制、铁素体轧制等新技术。认为：H^2结晶器与普通漏斗型结晶器相比,坯壳所受的应力大大降低,不易产生裂纹;优化的辊列设计及动态液芯压下技术确保了铸坯的内部质量;半无头轧制解决了超薄带钢直接穿带和甩尾困难的难题;动态PC和工作辊弯辊技术相互配合,保证了产品质量的稳定;而三点除鳞,尤其是粗轧和精轧之间设中间冷却装置,不仅可以改善板带表面质量,也为实现精轧在铁素体状态下轧制提供了条件。     

控轧控冷工艺对SCM435钢盘条组织和性能的影响

试验钢SCM435（/%:0.33~0.38C,0.15~0.35Si,0.60~0.85Mn,≤0.025P,≤0.025S,0.90~1.20Cr,0.15~0.30Mo）盘条的生产流程为80t BOF-LF-280 mm×325 mm铸坯-160 mm×160 mm热轧坯-热连轧成Φ16 mm盘条。试验研究了160 mm×160 mm热轧坯由常规轧制工艺（开轧1060℃,精轧930~950℃,吐丝860~900℃,冷却速度0.5~0.6℃/s）和控轧控冷工艺（开轧1060℃,精轧820~850℃,吐丝780~820℃,冷却速度0.4~0.5℃/s）对SCM435钢热轧盘条组织和力学性能的影响。结果表明,随着精轧温度的降低和冷却速度的减小,钢热轧盘条的组织得到改善,抗拉强度明显降低;常规工艺轧制SCM435钢热轧盘条的抗拉强度平均952 MPa,组织为铁素体+珠光体+贝氏体+马氏体,控轧控冷工艺轧制的SCM435钢热轧盘条的抗拉强度平均817 MPa,组织为均匀的铁素体+珠光体。结合控轧控冷工艺原理对钢的组织和性能变化进行了分析。     

两相区轧制对微铌低合金钢组织和性能的影响

结合Gleeble-3800热模拟试验机测定的微铌低合金钢CCT曲线，采用再结晶区轧制+未再结晶区轧制+(γ+α)两相区三阶段控制轧制工艺进行轧制试验，研究微铌低合金钢在(γ+α)两相区范围内不同变形率对组织和性能的影响，同时比较了两相区轧制与常规控轧控冷工艺轧制钢板的组织和性能。结果表明：微铌低合金钢两相区轧制工艺与常规控轧控冷工艺相比，屈服强度和抗拉强度升高，伸长率和冲击功有少许降低；两相区轧制工艺能够细化铁素体晶粒，但是也存在单个尺寸较大的铁素体晶粒。另外，随着(γ+α)两相区累计变形率的增加，微铌低合金钢的强度升高，韧塑性降低。     

梅钢1422mm传统热轧铁素体轧制研究

为了提升梅钢1 422 mm热轧制造能力,对传统热轧工艺进行铁素体轧制研究。通过针对性研究、工艺改进以及控制参数合理配置,梅钢1 422 mm热轧实现了低碳钢铁素体轧制。结果表明,新的工艺技术对热轧带钢的终轧温度和卷取温度有很好的控制能力,产品的综合性能得到有效提升。     

TMCP工艺下Ti-Mg氧化物冶金钢轧态组织性能

摘要：为研究轧制过程中氧化物粒子对母材组织性能的影响，提出了一种只在再结晶区进行轧制的新工艺路线，利用常规冶炼及氧化物冶炼的实验钢分析其轧态显微组织、力学性能及相变过程。结果表明：在新轧制工艺下，氧化物冶金钢母材显微组织由常规的贝氏体板条束变为针状铁素体，其基体具有良好的力学性能，-80℃冲击韧性达149J；热轧工艺下的组织转变分两阶段进行，初期是针状铁素体的形核和晶粒细化，之后贝氏体相变被限制在针状铁素体板条间构成的区域内。     

IF钢铁素体热轧轧制工艺

正IF钢是超低碳深冲用钢, 铁素体区轧制通常指粗轧在奥氏体区进行、精轧在铁素体区进行的一种新工艺。该工艺具有节约能源、降低成本的特点。1 IF钢铁素体与奥氏体的温度转变点图1为IF钢在冷速2 ℃/s时的温度-膨胀曲线,图2为IF钢在冷速20 ℃/s时的温度-膨胀曲线,从图上可以看出IF钢奥氏体与铁素体的相变点在890 ℃。在相变转化点,IF钢的塑性会发生突变,在相变点轧制力会发生突变。所以精轧区要避开相变点。要么精轧出口温度     

09V钢组织与性能的研究

研究了09V钢热轧工艺参数对奥氏体及铁素体晶粒的影响及铁素体晶粒对韧性的影响,以及冷速与组织性能的相互关系。试验结果表明:铁素体晶粒细化10μm,可使脆性转化温度下降8℃;控制热轧加热温度及形变量可有效地细化铁素体晶粒;提高轧后冷速可显著提高钢的强韧性。因此,09V钢在轧制型材时采用适宜的热轧工艺及轧后冷速,可全面提高钢的综合机械性能。     

Key technology and mechanism of ferrite rolling

Ferrite rolling is a hot strip rolling process which controls the finishing rolling process within the ferrite range. Compared with the traditional “hot rolling cold rolling annealing” process, ferrite rolling allows “hot rolled sheet instead of cold rolled sheet”, resulting in significantly cost savings. However, for some short production processes, high cooling rates between rough rolling and finish rolling can affect the size and microstructure of the product. Especially for low carbon steels with a wide two phase area, it is more difficult to achieve full ferrite region rolling. Based on a summary of the recent work on ferrite rolling plates and strips, the research and application of ferrite rolling process at home and abroad were discussed. Combined with the design characteristics, the ferrite rolling process parameters and the corresponding microstructure and property control targets were proposed. Several key issues in the application of ferrite rolling technology were focused on. The softening mechanism of two phase deformation and its effect on texture were discussed in detail. It aims to provide theoretical guidance for the future development of key technologies and control ideas for the control of key processes.     

Hot direct rolling in ferrite region in extra low-carbon steel

For the first time, hot direct rolling was applied in ferrite region in the mill and the resulting quality of the cold rolled and annealed sheet steel was as good as that hot direct rolled in austenite region with respect to microstructure and mechanical properties. In case of ferrite phase rolling, microstructure of the hot strip reveals abnormal grains and deformation bands in the grains, and elongation and r value are not so good as those rolled in the austenite phase. However, these abnormal grains left no traces and appeared to be equiaxed grains like the austenite phase rolled microstructure after 75 % cold rolling and continuous annealing at 830°C. This is attributed to the deformation bands which provide nucleation sites for recrystallization during annealing so that recrystallization occurs uniformly in the matrix. (111) texture was well developed and r value thus appeared high.     

Effect of Lubrication during Hot Rolling on the Evolution of Through‐Thickness Textures in 18%Cr Ferritic Stainless Steel Sheet

Samples of a ferritic stainless steel sheet were hot‐rolled with and without application of lubrication. The effect of the different hot rolling processes on the evolution of texture and microstructure after hot rolling, cold rolling and subsequent recrystallization annealing was studied by means of macro and micro‐texture analysis and microstructure observations. After hot rolling, the sample rolled with lubrication displayed uniform rolling textures through the sheet thickness, while the sample rolled without lubrication showed shear textures in the outer layers of the sheet. The finite element method was employed to reveal the strain states during hot rolling with and without lubrication. The texture of the hot rolled sheet strongly influenced the formation of texture after cold rolling and final recrystallization and, therewith, planar anisotropy as well as the severity of ridging of the final gauge sheet. Hot rolling with lubrication was beneficial to the formation of strong recrystallization textures through the whole thickness layers leading to an enhanced planar anisotropy of the sheet. The recrystallized sheet hot‐rolled without lubrication displayed less severe ridging, however, which was attributed to a less frequent formation of orientation colonies in the outer thickness layers of the sheet.     

铁素体轧制工艺热轧板显微组织研究与分析

为进一步摸清Ti- IF钢在铁素体轧制工艺下热轧板的金相组织分布规律,以及铁素体轧制工艺和常规轧制工艺下热轧板的金相组织差异性,结合某热轧厂半连轧生产线新开发的铁素体区轧制工艺技术,利用透射电镜试验对Ti- IF钢铁素体区轧制工艺的热轧板金相组织和析出物的控制情况作了初步研究,并分析了铁素体轧制工艺和常规轧制工艺热轧板金相组织以及析出物类别、晶粒尺寸的差异。研究可知,铁素体轧制工艺能得到细小均匀的再结晶晶粒,且比奥氏体晶粒尺寸小6~10 μm,其组织整体的均匀性理想。析出物方面,铁素体轧制工艺整体比奥氏体工艺大30~50 nm,不过TiN析出物尺寸相差不大。     

低温加热取向硅钢组织与织构演变研究

采用OM、EBSD、XRD分析研究了含Cu低温加热取向硅钢组织、织构的演变特征,研究结果表明：热轧板中存在铁素体层和珠光体层彼此交替的带状组织,且显微组织在厚度方向上分布不均匀,热轧板中{001}〈110〉、{112}〈110〉织构以及{110}〈001〉织构在板厚方向上分布不均匀;经过冷轧后,铁素体晶粒被严重拉长,形成了沿轧向伸长的纤维状组织,冷轧板织构类型主要是α织构和γ织构;脱碳时基体发生回复再结晶,显微组织为单一的铁素体等轴晶粒,织构主要为γ织构;二次冷轧板经渗氮后织构仅从强度上有所降低,其织构类型变化不明显。成品二次再结晶组织发展比较完善,晶粒尺寸约为10~20 mm。织构类型为锋锐的Goss织构。成品磁感B800达到了1.926 T,铁损P1.7/50为1.047 W/kg。     

热轧深冲钢板的分析和应用

在对比冷轧深冲钢的基础上,分析了工业试制的热轧深冲钢板的组织和性能。研究结果表明：该钢的碳含量较低,相应的金相组织和晶粒度合适;厚度大于２ｍｍ的钢板未经冷轧和退火处理可达到与冷轧深冲钢弧相当的成型性能,是代替冷轧深冲钢板冲压汽车零件的理想材料。该钢生产工艺简单,质量稳定,具有明显的经济效益和社会效益。     

国内外铁素体轧制的研究和应用

超薄热轧带钢(<1.2mm)的铁素体轧制(低温轧制)能显著节约能源和降低生产成本。当前迅速发展的薄板坯连铸连轧技术为铁素体轧制的发展与应用创造了良好的条件。已采用铁素体温轧工艺的钢板为低碳钢薄板和微合金化钢薄板。总结了铁素体轧制时流动应力,再结晶,轧后产品组织和性能的研究现状和铁素体轧制的应用情况。     

5083 H321铝合金板材制备组织性能研究

基于“1+4”热连轧生产线、2800mm冷轧生产线,采用不同工艺线路制备了5083 H321铝合金板材,研究了不同制备工艺对板材组织性能的影响。结果表明,不同工艺路线成品板材力学性能、耐腐蚀性能及微观组织均存在明显差异。采用“1+4”热连轧生产线短流程工艺制备的5083 H321铝合金板材性能:抗拉强度358MPa、屈服强度257MPa、延伸率17%、剥落腐蚀等级PA、晶间质量损失3.22mg/cm2。     

高强镀锌板表面发麻缺陷产生机理

针对高强镀锌板表面发麻缺陷问题，从全流程分析角度，探讨引起此缺陷的根本原因。利用扫描电镜分析发现，发麻原因在于锌层表面厚度不均匀、粗糙度差异明显以及镀锌板表面存在较多的表层裂纹。跟踪分析发现该表层裂纹主要产生在冷轧工序，结合钢种的热轧微观组织特点，提出形成表层裂纹的机理在于热轧钢板在轧制过程中抗开裂能力较弱，导致冷轧过程中钢板表面形成 10 μm 的表层裂纹。结合 CCT 曲线的模拟分析发现，控制热轧钢板表层微观组织状态可以明显抑制高强镀锌板表面发麻缺陷的产生。     

Effects of Process Parameters prior to Annealing on the Formability of Two Cold Rolled Dual Phase Steels

This study concerns the effects of coiling temperature after hot rolling and the degree of reduction during cold rolling on formability‐related properties of high strength cold rolled dual phase (DP) steels. The effect of coiling temperature on the final structure and properties of two cold rolled and annealed DP‐steels is investigated. Further, the effect of cold rolling reduction and its impact on the final properties of the material is studied. Aspects of the impact of the different process parameters on the ferrite to austenite and austenite to martensite transformation are discussed based on results from production scale experiments, tensile testing and metallographic examinations of the materials.