预轧-退火对Cu-7.5Sn-0.1P带材组织与力学性能的影响

本研究对铸态Cu-7.5Sn-0.1P合金进行预轧再退火,并采用XRD、OM、SEM、EDS、EPMA和拉伸测试等方法,研究预轧变形量和退火温度对合金的微观组织和力学性能的影响。结果表明:对于预轧的Cu-7.5Sn-0.1P合金而言,预轧变形造成枝晶结构的破碎,有利于锡偏析组织在较低退火温度下的消除。与直接退火的合金相比,预轧-退火处理的合金晶粒尺寸小,强度高,还保持了良好的塑性变形能力。预轧-退火的合金经冷轧、去应力退火最终制得0.2 mm厚的成品带材,与常规工艺制备的相似厚度和成分的锡磷青铜带材相比,其强度显著提高并保持较好的塑性,其中,对应于预轧变形量为44%、退火温度为620℃的合金带材的抗拉强度与伸长率分别达到1005 MPa和19.3%。

82B钢4道次预精轧过程的计算机模拟和分析

采用非线性有限元分析软件ABAQUS,通过建立的线材与轧辊的3维热机耦合模型,对钢厂82B钢(/%:0.79～0.86C、0.15～0.35Si、0.60～0.90Mn、≤0.030S、≤0.030P)φ20mm至φ16.5mm 4道次预精轧过程中轧件的温度场、应力-应变场和轧制力进行数值模拟和分析。结果表明,数值模拟结果与实测结果相符;预精轧过程轧件心部温度和表面温度的差值为～130℃;运用该模型对现场轧制过程中的前滑进行了分析,得出了影响前滑的因素主要有延伸系数、轧制孔型尺寸、轧制速度以及辊径与轧件厚度比值。

离速线材轧机预精轧机架辊环的研制与应用

<正> 1.概况上钢二厂高速无扭线材轧机是引进美国摩根公司的二手设备,技术装备水平具有70年代末、80年代初水平,可将100mm 方坯轧制成φ5.5～13mm 共17种规格的普碳、优质、焊条和其它合金钢种线材,产品盘重大,质量达到国际先进水平。轧制φ5.5mm 线材时成品线速度可达76.2～84m/s。年产量设计能力为52×10~4t。该套轧机由粗、中轧机组,

高线预精轧孔型系统优化设计生产实践

通过共用预精轧的G14-01,G16-02孔型,重新设计G15-03孔型,使不同系列产品预精轧前三道次孔型实现了共用,降低了员工的劳动强度,缩短了更换品种系列的时间,降低了生产成本,减少了备辊量。

预精轧SM150功率模块烧坏原因分析及处理

针对山西通才工贸有限公司双高线A线预精轧SM150传动柜IGBT功率模块烧毁情况,分析故障曲线、查看OP177故障记录并追溯判断故障来源,综合各种情况并通过排除法找出烧毁原因,最终提出相应的处理方法和注意事项。

一高线预精轧机组孔型系统通用化设计

本文根据水钢轧钢厂一高线实际生产情况，通过分析该生产线孔型多系列的特点，将3套基本孔型系列设计为2套孔型系列。解决了一高线预精轧机组更换规格时间长、辊环库存量大等问题。

高线轧线上先进设备的应用

就摩根在高线生产实践中的创新简单介绍了其中的先进设备,如预精轧机、V型顶交无扭轧机、摩根控制系统前后的水箱、导位、减/定径机等。

TC4钛合金热连轧棒材孔型改进

为了使φ15·5 mmTC4钛合金热连轧棒材组织更加均匀、晶粒更加细小、性能更加优异,优化设计了φ15·5 mm TC4钛合金热连轧预精轧棒材孔型,并对比分析了原孔型和优化孔型轧制的φ15·5 mm TC4钛合金棒材预精轧各道次的变形量、显微组织和力学性能。实验结果表明,优化设计的φ15·5 mm TC4钛合金热连轧预精轧棒材孔型中除预精轧2的道次变形量比原孔型低,其余各道次的变形量几乎都高于原孔型,而且都在20%以上;采用优化孔型轧制的φ15·5 mm TC4钛合金热连轧棒材显微组织中初生α相含量较原孔型轧制的初生α相含量增多,其分布更加均匀、细小;优化孔型轧制的棒材各项力学性能都优于原孔型轧制的棒材。

消除443系不锈钢表面线状缺陷的研究

为消除或减轻443系不锈钢表面存在线状缺陷,研究了热线抛丸、刷洗机工艺参数及预轧修磨对消除线状缺陷的影响。结果显示增大热线抛丸转速、提高抛丸电流和刷洗机使用带磨料的刷毛、增加刷辊转速及电流可以使合格率提高0.92%,预轧修磨可以使表面合格率提高3.13%。

提高GCr15轴承钢线材预精轧温度的研究

通过提高GCr15轴承钢10 mm线材预精轧温度的工业试验,得到了网状碳化物少的细片状珠光体组织,利用实验室热模拟的方法对工业试验现象做了进一步分析。结果表明:当预精轧温度为944℃时,试验钢网状碳化物析出时恰好处于快速冷却阶段,故其析出得到抑制,球化退火后渗碳体颗粒均匀细小,网状级别可降低至1.5级,布氏硬度为202.72,强韧性能均较高,满足GB/T18254-2002《高碳铬轴承钢》和实际生产对GCr15轴承钢退火材的要求。

NEL装置浅议

较详细地介绍和分析了大冶钢厂１７０无缝钢管厂阿塞尔轧管机ＮＥＬ装置的结构及特点，说明了ＮＥＬ装置以预轧方式较圆满地解决三辊轧管机轧制薄壁管的“尾三角”问题，并初步探讨了涉及预轧孔型的辊数和倾斜角等参数。

Application of the Plate Crown Prediction

The program of the plate crown optimal prediction applied in the plate mill of Wuhan Iron and Steel(Group) Co. Ltd. is described. Optimal prediction is programmed in ALPHA 4000. The original profile, wear, expansion and deformation of work rolls are introduced into the program. The plate crown is controlled by the original profile of work rolls and the draft whose objective is the optimal plate crown. The run schedule is also optimized through the optimal prediction of the plate crown.

Adaptive Modification of the Rolling Force Prediction

In rolling process, the rolling force is an important parameter. The precision of the predicted rolling force will directly affect the precision of the finished product. By using adaptive control theory and fusing the measured and predicted data, the precision of the predicted rolling force is gradually improved. This system has been used in plant for more than one year, and the result of the application shows that the system has steady and reliable performance, and high precision.

Effect of pre-rolling path on mechanical properties of rolled ZK60 alloys

Pre-cold rolling with low reductions(<3%)was used to improve the mechanical properties of rolled ZK60 plates.The effects of rolling path on mechanical properties were investigated in detail.Both pre-cold rolling along the transverse direction(TD)and pre-cold rolling along the normal direction(ND)can increase the yield strength.However,pre-cold rolling along the TD is more effective than pre-cold rolling along the ND in improving the comprehensive mechanical properties.After pre-cold rolling to 3%reduction,the sample rolled along the TD and the sample rolled along the ND have similar tensile yield strength(~270 MPa).However,the former has a higher compressive yield strength,lower yield asymmetry and larger toughness than the latter.Moreover,pre-cold rolling can also enhance precipitation hardening effect.However,aging treatment cannot further improve the yield strength of pre-cold rolled samples.Finally,the related mechanism is discussed.

Analysis and prediction of fishtail during V-H hot rolling process

The fishtail in head and tail of the slabs was studied during V-H hot rolling process. With the application of ANSYS/LS-DYNA, simulation analysis was used to research this process. The various factors which have a great influence on fishtail shapes were analysed, such as initial width, initial thickness, radius of the edger roll and horizontal roll, edging draught,horizontal reduction rate, and friction coefficient of the surface. Then the curves that can describe the shapes were obtained. After a certain time of self-learning, the optimized curves were given out. At last, through the fitting of the simulation test results, the math models for the area of fishtail defect changing with the presented factors were received. The experimental results show that the accuracy of the prediction for the fishtail shapes is more than 95%. With the application of the prediction for the fishtail shapes and the area of the fishtail defect, the loss rate of the slab is decreased by about 0.1%.

Strength prediction of multi-layered copper-based composites fabricated by accumulative roll bonding

This work aims to evaluate the feasibility of the fabrication of nanostructured Cu/Al/Ag multi-layered composites by accumulative roll bonding(ARB),and to analyze the tensile properties and electrical conductivity of the produced composites.A theoretical model using strengthening mechanisms and some structural parameters extracted from X-ray diffraction is also developed to predict the tensile strength of the composites.It was found that by progression of ARB,the experimental and calculated tensile strengths are enhanced,reach a maximum of about 450 and 510 MPa at the fifth cycle of ARB,respectively and then are reduced.The electrical conductivity decreased slightly by increasing the number of ARB cycles at initial ARB cycles,but the decrease was intensified at the final ARB cycles.In conclusion,the merit of ARB to fabricate this type of multi-layered nanocomposites and the accuracy of the developed model to predict tensile strength were realized.

高线活套装置改造

针对萍乡萍钢安源钢铁有限公司轧钢二厂的高速线材生产线预精轧机组活套装置存在起套辊轴承易抱死、侧活套底板耐磨引导条磨损过快和5号侧活套甩尾打结的问题进行相应改造后,提高了轧机有效作业率,降低了生产成本。

Rolling force prediction for strip casting using theoretical model and artificial intelligence

Rolling force for strip casting of 1Cr17 ferritic stainless steel was predicted using theoretical model and artificial intelligence.Solution zone was classified into two parts by kiss point position during casting strip.Navier-Stokes equation in fluid mechanics and stream function were introduced to analyze the rheological property of liquid zone and mushy zone,and deduce the analytic equation of unit compression stress distribution.The traditional hot rolling model was still used in the solid zone.Neural networks based on feedforward training algorithm in Bayesian regularization were introduced to build model for kiss point position.The results show that calculation accuracy for verification data of 94.67% is in the range of ±7.0%,which indicates that the predicting accuracy of this model is very high.

Characterization of mechanical and corrosion properties of cryorolled Al 1100 alloy:Effect of annealing and solution treatment

Effect of annealing and solution treatment prior to cryorolling on the formation of initial structure influencing microstructure formation from nano to micron scale and resultant mechanical and corrosion properties in Al 1100 alloy has been studied in detail.Before subjecting to 50%cryorolling,samples were pre-annealed at 250℃ for 2 h and pre-solution treated at 540℃ for 1 h.X-ray diffraction and HRTEM techniques were used to understand the crystallite size,lattice strain and dislocation configuration in the processed alloy.The results indicate that the pre-annealed sample has the highest grain aspect ratio(4.43),the smallest crystallite size(37.53 nm),the highest lattice strain(9.12×10^(−3))and the highest dislocation density(45.16×10^(13) m^(−2))among the tested sample.The pre-annealed sample shows a significant improvement of 43.44%,24.64%and 20.33%in hardness,ultimate tensile strength and yield strength.Both pre-annealed and pre-solution treated samples show improved corrosion resistance when compared to cryorolled samples without any pre-treatment,with the pre-annealed sample showing the best corrosion resistance.

Artificial neural network prediction of mechanical properties of hot rolled low carbon steel strip

Conventionally, direct tensile tests are employed to measure mechanical properties of industrially pro- duced products. In mass production, the cost of sampling and labor is high, which leads to an increase of total pro- duction cost and a decrease of production efficiency. The main purpose of this paper is to develop an intelligent pro- gram based on artificial neural network （ANN） to predict the mechanical properties of a commercial grade hot rolled low carbon steel strip, SPHC. A neural network model was developed by using 7 x 5 x 1 back-propagation （BP） neural network structure to determine the multiple relationships among chemical composition, product pro- cess and mechanical properties. Industrial on-line application of the model indicated that prediction results were in good agreement with measured values. It showed that 99.2 % of the products＇ tensile strength was accurately pre- dicted within an error margin of ~ 10 %, compared to measured values. Based on the model, the effects of chemical composition and hot rolling process on mechanical properties were derived and the relative importance of each in- put parameter was evaluated by sensitivity analysis. All the results demonstrate that the developed ANN models are capable of accurate predictions under real-time industrial conditions. The developed model can be used to sub- stitute mechanical property measurement and therefore reduce cost of production. It can also be used to control and optimize mechanical properties of the investigated steel.