热轧哈芬槽钢生产技术开发

介绍了辽宁中车轨道交通装备有限公司连续热轧热弯哈芬槽钢生产线的工艺特点、主要设备和孔型系统,提出了热轧哈芬槽钢生产中存在坯料宽度选择、中间坯尺寸控制和连续热弯成形3个关键问题及相应的解决办法。     

采用小异型坯生产大规格槽钢的工艺创新

为进一步扩展市场,马钢在其小H型钢生产线上对大规格槽钢产品进行了开发。而采用纯孔型轧制大规格槽钢存在孔型设计较为复杂,相邻规格间孔型共用性较差,现场备辊量较大,换辊次数较多等问题。为此,对该产线孔型系统进行了研究,提出了万能直轧混合孔型系统,并介绍了其中粗轧孔型、中精轧万能孔型、控制孔型的优化设计。采用混合孔型系统,生产相邻型号槽钢时仅需备1套S₁₂~S₁₅机架孔型,其余孔型实现了全部共用。通过工艺创新,已成功开发出24^#、25^#全厚度槽钢产品,解决了二辊孔型共用性差的问题,同时减少了轧辊等备件量,实现了快速更换产品规格;以较低的开发投入,提高了生产效率,提高了产量。     

槽钢辊弯成形过程的有限元仿真

以大变形弹塑性有限元方法为基础．利用MARC软件对槽钢板坯进行了三维大变形模拟，分析了在辊弯成型过程中不同道次辊压所造成的槽钢各部位应变和应力的分布情况．揭示了槽钢在成型过程中金属的变形规律。从而为生产与设计，特别是孔型设计提供了可靠的理论依据．为计算机孔型设计与制造系统奠定了基础。     

参数化槽钢孔型计算机辅助设计技术研究

基于参数化思想,对槽钢孔型计算机辅助设计技术进行了研究,同时使用Delphi对AUtoCAD进行了二次开发。结合武钢万能轧机槽钢孔型系统,介绍了系统应用实例。该系统可以有效缩短新产品的开发周期、提高孔型设计的可靠性、降低轧制时的各种消耗、加快新产品的研发速度。     

槽钢孔型设计浅议

分析了用于槽钢生产的弯腰式、蝶式、大斜度式3种孔型系统的优缺点，指出采用大斜度式孔型系统可使生产稳定，轧辊消耗少，槽钢腿部尺寸精度高，因此该孔型系统是槽钢生产的首选。     

22a号槽钢蝶式孔型设计

介绍了 2 2a号槽钢超负差轧制的蝶式孔型设计 ,并与弯腰直腿大斜度孔型系统进行了比较 ,分析指出了蝶式孔型的优点。     

轻型槽钢与蝶式孔型设计

将同型号的轻型槽钢与普通槽钢进行了比较 ,轻型槽钢显示出明显的优越性 ,是一种经济断面钢材。以 14# 轻型薄壁槽钢为例 ,介绍了其蝶式孔型系统的优点及设计要点。     

小号槽钢的孔型设计

我厂生产5号普通槽钢是在φ500/φ300车间进行的。轧机布置是一台1000kW的电动机拖动两架φ500轧机及用一台630kW的电动机拖动三架φ300轧机构成二列布置。70mm方坯在长20m、宽3.7m的燃煤加热炉中加热,然后在φ500轧机上轧制了道,在φ300轧机上轧制3道成材,最后精整入库。 5号普通槽钢在我国现行槽钢标准中为最小规格,由于该产品的断面形状为腰窄腿长,腿长与腰宽比值达0.74,这在普通槽钢各品种中为最大,所以称为深槽槽钢。它给孔型设计增加了难度,不能采用通常大斜度弯腰孔型系统的设计方法。我们采用了斜度较大,但又近直轧法类型的孔型设计方法。实践表明,这种设计方法对小型槽钢的孔型设计是可取的。孔型系统采用闭口式、槽口向下的孔型系统。这种孔型系统具有产品质量稳定,轧制过程轧件温降小的优点。但是槽孔下部冷     

工程机械用类槽钢-引导轮轧制变形规律

借助有限元分析软件ANSYS/LS-DYNA,定性的模拟分析工程机械用类槽钢-引导轮在轧制过程中的变形规律,通过实验室石膏辊轧制橡皮泥实验,对模拟结果进行验证以及对比分析。实验结果表明,类槽钢-引导轮的变形不均匀,主要是类槽钢槽底圆角处的变形速度过大,分布的应力应变较大所致。采用适当增大槽底圆角半径无助于应力应变分布情况的改善,而采用原始孔型设计,则可得到应力应变的最佳结果,得到合格产品。     

汽车用特殊槽钢的研制与开发

马鞍山钢铁股份有限公司成功开发了一种轿车用长腿特殊槽钢，介绍了该槽钢的化学成分、力学性能以及孔型设计和试生产情况。     

Deformation mechanisms of pure Ti during equal channel angular pressing

The microstructural development of commercially pure titanium was investigated to elucidate the mechanisms of grain refinement and strain accommodation during equal channel angular pressing. The samples were processed at 623 K via route C, in which the sample was rotated 180° around its longitudinal axis between the passes. TEM micrographs of the sample undergoing the first pass revealed that the strain imposed by the pressing is accommodated mainly by {1011} deformation twinning. During the second pass, the deformation mechanism was changed to dislocation slip. TEM analysis indicated that the slip system consisted of alternating twin bands containing dislocations ofa slip on a prismatic plane and ofa+c slip on a pyramidal plane. Microstructural evolution in commercially pure titanium subjected to equal channel angular pressing was discussed based on the preferred orientation formed during the first pass and resolved shear stress for the slip systems.     

Recrystallization of high-purity aluminium during equal channel angular pressing

Aluminium with 5N purity were deformed at room temperature by equal channel angular pressing following Route A up to three passes. The microstructure and the crystallographic texture were investigated by orientation imaging microscopy and electron backscatter diffraction, respectively. The microstructure showed complete recrystallization after the first ECAP pass onwards. The grain size decreased slightly with increasing number of passes. The corresponding texture consisted of an oblique cube component. The oblate grains and the cube texture were rotated anticlockwise about the transverse direction. The inclination of grains with respect to the direction of ECAP was dependent on the distance from the top of the billet and changed from pass to pass. The mechanism of formation of the microstructure and texture is discussed in the light of the physical phenomena involved.     

The finite element analysis of equal channel angular pressing (ECAP) considering the strain path dependence of the work hardening of metals

It is widely known that extreme grain refinement of metals can be attained through multiple passes of equal channel angular pressing (ECAP). Such processing can follow various strain paths, which correspond to different work hardening behaviors of the material being deformed. The available finite element analyses (FEA) of multiple pass ECAP do not consider this strain path effect, and employ a single stress–effective strain curve of the material for all passes. The present paper presents a FEA of a two pass ECAP processing of copper following route C. This processing route involves the shearing of the material in the same plane as in the first pass, but in a reversed shear direction. The experimental stress–strain curve of the material, considering this strain path change, was determined through reversed torsion at various strain levels associated with the strain heterogeneity in the material caused by the first ECAP pass. The consideration of the strain path effects changed the final strain distribution in the material and led to a lower punch force in the second pass, in comparison with the results from the analysis considering a single stress–strain curve for all passes.     

Processing and properties of ultrafine-grain aluminium alloy 6111 sheet

The equal channel angular processing (ECAP) technique has been applied to an automotive aluminium alloy sheet (A6111). The technique utilizes a machine that was specially designed for this purpose at Monash University. It was determined that ECAP is able to refine the grain size of the sheet, diminish the detrimental as-rolled texture components in the sheet and retain an acceptable level of bi-axial ductility such as is required during the automotive forming process. Experiments were carried out on annealed, as-received sheets that were subjected to either one or two passes through the ECAP machine. For the second ECAP pass, the sheet could be processed in the same orientation as the first pass (route A) or it could be rotated 180° about the direction of feeding (route C). It was determined that route A produced marginally improved properties compared to sheet processed via route C, and that due to the frictional heating generated during the second pass, a significant amount of recovery occurred in the sheet such that an improved combination of texture and formability resulted after two passes compared to the same sheet exposed to only a single pass.     

Q235钢C方式等径弯曲通道变形及组织研究

在室温下对Q235钢成功进行了C方式11道次等径弯曲通道，等效应变约高达11，获得了亚微晶铁索体组织。组织观察表明，第1道次组织细化效果最显著，随后道次的主要作用是增加晶粒的位相差，使大角度晶界的比例随变形道次增加而增加。在本实验条件下，由于珠光体组织中的渗碳体表现出较强的塑性变形能力，使得珠光体组织具有与铁素体类似的宏观塑性变形行为，并且在等效应变约高达11的情况下，珠光体组织中未发现微观裂纹。     

大规格圆棒连轧孔型系统探讨及实例分析

介绍了大圆棒半连轧生产中中轧机组轧制[Φ]120 mm规格和中精轧机组轧制[Φ]45 mm规格时的辊缝调整及其优化效果,并对中轧机组4道次轧制[Φ]200～[Φ]220 mm规格的孔型系统进行了优化设计,简化了孔型数量,实现了大规格圆棒的稳定生产。     

400mm×200mm×5mm冷弯等边槽钢孔型设计

介绍了冷弯等边槽钢的腹宽与腿长之比不小于2、腿长与壁厚之比不小于22·5时的孔型设计与计算参数及成型条件。在其孔型设计中,合理地分配了成型道次和弯曲角。并通过孔型设计和实践,探讨了其易产生的缺陷及解决对策。     

扩腰孔型在连轧工字钢中的实际应用

介绍了采用半连轧工艺生产工字钢的工艺流程,根据现有连轧生产设备和工艺,对孔型系统进行了优化设计,将扩腰孔型应用到连轧工艺中,在同一套孔型中仅更换3个孔即可轧制不同规格的工字钢,降低了企业生产成本,增加了企业竞争力。     

等通道转角挤压对L2工业纯铝力学性能的影响

利用等通道转角挤压(ECAP)技术挤压工业纯铝L2，探讨了挤压次数对其力学性能的影响。结果表明，随挤压次数的增加，L2的抗拉强度和硬度得到显著提高，抗拉强度可提高95％，硬度提高70％。挤压1次后，其伸长率由40％下降至15％，此后伸长率基本保持稳定。