RH精炼温度与合金模型的开发与应用

根据RH精炼处理对过程控制的要求,建立了RH温度与合金最小成本模型。该模型具有以下功能：（1）实时计算钢水温度的不断变化,并预报未来时刻钢水的温度;（2）计算达到目标成分需要投入的合金组合、合金数量。该模型在宝钢2号RH得到成功应用。     

新型钢包整体温度场和应力场三维数值模拟

针对新型300t钢包,采用三维有限元数值模拟的方法研究了包壳的整体温度场分布。重点研究了包壳外表面高度方向、桶体与包底连接环焊缝处的温度分布以及钢包一些辅助结构对包壳温度场的影响,从而掌握钢包包壳温度场的分布规律,为新型钢包的日常维护以及如何延长钢包的使用寿命等方面的工作提供一定的依据。     

20MnSiNb钢的显微组织及其对屈服行为的影响

采用金相组织观察和透射电子显微分析等手段,研究了20MnSiNb钢的显微组织对屈服行为的影响及添加微合金元素铌对其产生的作用。结果表明,贝氏体组织的形成将导致屈服平台的消失;钢中铌的沉淀析出具有沉淀强化和晶粒细化的作用。     

国产T23钢高温时效时组织和力学性能的研究

采用光学显微镜、扫描电镜、透射电镜观察和拉伸、冲击试验等方法,研究了国产T23钢在600 ℃时效时的组织变化和力学性能.结果表明,T23钢在600 ℃时效时随着时效时间的延长,T23钢中M23C6型碳化物不断粗化,粒状贝氏体形貌逐渐退化.时效时间较短时,主要是M23C6型碳化物粗化引起T23钢力学性能下降;时效时间较长时,主要是粒状贝氏体形貌的变化导致T23钢力学性能下降,同时,M23C6的球化及其向M6C的转变、亚晶的形成和W、Mo固溶强化的降低加快了T23钢力学性能的下降.     

SFT型半硬同轴电缆中内导体的选用

SFT型半硬同轴电缆要求其内导体具有较高的强度和较低的导体损耗。从材料、物理状态、尺寸等方面详细阐述了内导体的选择过程。指出了尺寸一致性较好的银层厚度为3um的30％IACS软态镀银铜包钢线作为SFT型半硬同轴电缆的内导体较为合适。     

整体型微孔聚四氟乙烯绝缘工艺初探

介绍了整体型微孔聚四氟乙烯绝缘推挤工艺的加工设备和工艺原理,阐述了对该工艺的初步探索结果,着重分析了工艺过程中的几个重要因素.选择合适的聚四氟乙烯树脂和挤出助剂以及对原材料正确的预处理是获得优质微孔聚四氟乙烯绝缘的前提.模具设计和配置会对工艺产生重大影响.根据电缆设计要求的等效介电常数计算出所需要的拉伸速度比的计算方法...     

Study on grain refinement of interstitial-free steel during continuous frictional angular extrusion

To explore the application of severe plastic deformation for grain refinement in steel production,a new method called continuous frictional angular extrusion (CFAE) was applied to refine the grain of interstitial-free steel.The deformation was carried out at room temperature and individual sheet specimens were processed in different number of passes.An overall grain size of 200nm was achieved after 8 passes and the proportion of high-angle boundaries to the total boundaries was more than 60%.Through the characterization of high resolution EBSD,X-ray diffraction (XRD) and hardness testing,this paper discussed the evolution of microstructures and textures during deformation and explored the development direction of the method.     

Multi-objective optimization for roll shifting strategy in cross rolling campaigns of hot strip mill

A multi-objective optimization approach for the roll shifting strategy in cross rolling campaigns of hot strip mills is presented.The effect of different roll shifting strategies on roll wear contour is studied by numerical simulation,and two evaluation indexes,namely body smoothness and edge smoothness,are proposed.The average body smoothness and average rolling edge smoothness of all strips in a rolling campaign are taken as the objective functions,the shifting positions of all wide strips as the decision variables,and the multi-objective method of NSGA-Ⅱ as the optimizer.Thus a multi-objective optimization model for the roll shifting strategy is built.The simulation results show that work roll shifting can make wear contour smooth,and a dish-shaped wear contour without severe local wear can be achieved by the roll shifting strategy with varying stroke.Optimization experimentation shows that by means of NSGA-Ⅱ,a good Pareto-optimal front can be obtained,which suggests a series of alternative solutions for roll shifting strategy optimization.The experimentation also shows that there is a conflict between the two objectives.Finally,application cases confirm the feasibility of the multi-objective approach,which can improve the strip profile,reduce edge waves and extend the rolling miles of a rolling campaign.     

精锻机蜗杆轴承装配和调整

介绍了精锻机蜗杆轴承中重要部件装配间隙的调整、相配精度检查和控制，解决了推力轴承间隙调整问题，达到了高精度轴承的要求，保证了设备运行的稳定性和可靠性。     

High performance ferritic stainless steel B445R for architectural applications

Traditionally,austenitic stainless steels 304 and 316 have been employed in coastal regions as roofing materials unfortunately,they are expensive and not fully resistant to pitting corrosion under severe coastal corrosive environment.A ferritic stainless steel B445R was developed.Compared with austenitic 316L,B445R is①less costly;②uperior corrosion resistant with minor maintenance for long-term service;③insusceptible to thermal distortion in the welding seam. B445R sheet shows a higher yield strength and lower tensile strength,lower elongation and lower work-hardening than austenitic 316L.It can be easily fabricated and deformed just like plain carbon steel.After bending 180o,there is no occurrence of "cracking" or noticeable "orange peel".The formability of the welding seam is also satisfactory.The pitting potential of B445R is 650 mV,larger than that of 304 and 316L,as shown in Fig.1. The corrosion rate of B445R submerged in 6%FeCl,solution is 0.3 -0.56 g/(m² ? h^-1),much lower than that of 316L,as shown in Fig.2.The superior pitting corrosion resistance of B445R can be ascribed to synergetic effect of higher Cr and Mo. Dull-finished B445R sheets have been employed as the roofing materials for Guangzhou Asian Games Arena,as shown in Fig.3.About 380 t of 1.0 mm B445R with dull finish was used for roofing panels.About 100 t of 0.8 mm B445R with hairline or fluororesin paint finish was used for side wall panels.The composite roof build-up （from up to bottom） includes:①shingles of ferritic stainless steel B445R;②Kalzip-type standing seam of austenitic 304;③water-proof DFM;④structural steel;⑤75 mm thick insulation;⑥secondary purlin of 150 mm×100 mm×4.5 mm of galvanizied Q235;⑦0.8 mm thick profile deck of galvanizied Q235;⑧acoustic insulation.The roofing shingles or panels with the same width but different length were formed by bending four sides and fixed to a "L" shape reinforcing frames of stainless steel by fasteners.The "L" frames was connected to ribs of the standing seam by a clamping fixture made of aluminum.