曲轴CAPP专家系统研究

采用以型面特征为基础,以轴段信息为单元建立曲轴ＣＡＰＰ信息模型的方法,既能与ＣＡＤ系统和ＣＡＭ系统在特征层上实现信息集成,又能获得符合企业规范的工艺规程。工艺揄吸收了派生法和创成法的优点,采用专家系统结构顺应了新一代ＣＡＰＰ的发展潮流。     

铸态珠光体球铁曲轴生产工艺的研究

铸态珠光体球铁曲轴的生产过程应严格控制铁液化学成分,采用正确的球化处理工艺和瞬时孕育,加入适量的铜、锡、方可稳定生产铸态珠光体球铁曲轴。     

35CrMo曲轴热成形材料模型的研究

本文通过对大型曲轴用钢３５ＣｒＭｏ的热力模拟试验和数据处理,探讨了曲轴弯曲镦锻的热成形机制,研究了变形温度,应变速率等参量对３５ＣｒＭｏ钢应力应变关系和再结晶特征的影响。建立了该类钢热成形的材料模型、给有限元数值模拟曲轴弯曲镦锻热成形过程提供了基本数据,也为大型曲轴热成形力能参数和温度制度的合理确定提供了科学依据。材料模型的确定,对于研究热成形实质,预报与控制工艺质量和产品质量乃至新工艺开发都有重     

高强度紧固件用冷作强化非调质钢的研究开发

采用冷作强化非调质钢来制造高强度紧固件,可省去钢材冷拔前的退火处理和螺栓成形后的调质处理,在很大程度上简化了生产工序,缩短了生产周期,降低了能源消耗,同时还避免了因热处理而造成的表面氧化、脱碳及工件变形等问题,因而具有显著的经济效益和社会效益,采用热机械轧制工艺,通过化学成分优化及使用技术研究,开发出了8.8、9.8、10.9级螺栓用冷作强化非调质钢。     

铸态珠光体球铁曲轴生产工艺的研究

铸态珠光体球铁曲轴的生产过程应严格控制铁液化学成分,采用正确的球化处理工艺和瞬时孕育,加入适量的铜、锡,方可稳定生产铸态珠光体球铁曲轴.     

曲轴滚压校直专家系统的研究

针对曲轴滚压校直过程中出现的问题，设计出指导曲轴滚压校直操作的专家系统。该系统不仅能自动控制曲轴的测量和滚压校直的全过程，具有较强的状态监控能力，而且能够根据待加工曲轴的材料机械性能，疲劳强度要求和变形范围等输入参量，运用已有的工艺数据库，自动给出滚压校直加工工艺。     

汽车曲轴的动力学建模

建立普通轿车曲轴系统仿真模型,并通过仿真计算,分析了曲轴在安装及运行状态下的扭转、震动.并将分析结果与实测扭震进行了对比.     

曲轴成品质量中心定心法及算法研究

提出了一种加工曲轴定位中心孔的新工艺方法,即成品质量中心法,能够改善传统曲轴定心工艺的许多不足。采用逆向工程技术,获取曲轴毛坯曲臂部分的所有几何信息,然后依据动平衡特性,迭代搜索预测了曲轴成品质量中心轴线,从而实现曲轴成品质量中心定心法的关键算法。     

正火加热温度对非调质钢30Mn2V显微组织及性能的影响

以非调质钢30Mn2V为研究对象,分析了正火温度对奥氏体晶粒尺寸与室温显微组织及冲击韧性的影响。结果表明:在亚临界区附近正火,缓慢冷却,可使其冲击韧性大幅度提高,U型缺口冲击值αku可达120J/cm2以上。主要原因是晶粒细化、铁素体含量增多、组织均匀化和珠光体形态变化等。     

大型42 CrM oS4圆钢锻材的淬火工艺优化

对大型42 CrMoS4圆钢锻材淬火出现粗晶、魏氏组织的原因进行分析表明,冷却方式及淬火介质是产生组织缺陷的主要原因。优化淬火工艺可以有效改善组织、细化晶粒和提高力学性能,满足生产技术要求。     

42CrMo合金结构钢的切削加工有限元分析

采用有限元方法构建了42CrMo(美国牌号AISI 4140)合金钢的正交切削仿真模型,并对其进行了二维有限元仿真.切削仿真中,利用Johnson-Cook本构模型确立工件材料模型,刀屑界面摩擦采用剪切摩擦,分析温度场时把热传导系数设置为在刀屑界面上产生的压力函数.切削仿真结果表明:增大刀具前角,切削力下降;提高切削速度,则切削温度上升,等效应变速率明显加快.     

Corrosion behavior of tempered dual-phase steel embedded in concrete

Dual-phase(DP) steels with different martensite contents were obtained by appropriate heat treatment of an SAE1010 structural carbon steel,which was cheap and widely used in the construction industry. The corrosion behavior of DP steels in con-crete was investigated under various tempering conditions. Intercritical annealing heat treatment was applied to the reinforcing steel to obtain DP steels with different contents of martensite. These DP steels were tempered at 200,300,and 400°C for 45 min and then coo...     

On the design and selection of vehicle coordination policies for underground mine production ramps

Traffic management in underground mines,especially on production ramps,is a difficult problem to optimize and control.Most operations use one of a few common policies;e.g.,the so-called ‘‘lock-out" and‘‘loaded-vehicle-priority" policies.The work presented in this paper uses discrete-event simulation to study the efficiency of multiple policies.Based on simulation results,an improvement to the common lock-out policy is proposed.This new policy utilizes the rules of the lock-out policy but integrates an option that allows a group of vehicles to be given temporary priority in a certain direction of travel.Quantitative results are provided and,based on these,a systematic technique for ramp design that aims to optimize the efficiency of underground mine ramp traffic flow is described.     

EAF+LF/VD生产低硫钢的试验研究

研究了影响EAF+LF/VD工艺生产低硫钢的因素.结果表明降低出钢硫含量及加强出钢过程脱氧(出钢后渣中的(FeO+MnO)小于1.5%及钢液中溶解氧小于10×10-6),LF精炼过程保证渣碱度在5以上及包括出钢在内的40 min精炼时间,VD具有较强的脱硫能力.     

基于高炉焊接制造的BB503钢板焊接工艺研究

根据高炉炉壳生产实际,分别使用气电立焊和埋弧自动横焊两种焊接工艺对50 mm厚的BB503型炉壳用钢板进行焊接,对焊缝进行外观检查、无损探伤,对焊接接头进行拉伸、侧弯、冲击、硬度等性能测试,并对焊接热影响区的显微组织进行了观察和分析。结果表明,BB503炉壳用钢的气电立焊和埋弧自动横焊焊接接头抗拉强度和冲击吸收功均大于母材,具有优良的综合力学性能;焊缝区及热影响区的显微维氏硬度分布和热影响区的组织均匀性均显著优于传统的CO2气体保护焊和手工电弧焊接头。气电立焊和埋弧自动横焊工艺可以替代CO2气体保护焊和手工电弧焊工艺用于高炉炉壳焊接制造。     

Theoretical calculation of the impact work in the alloying non-quenched and tempered steel

Liu et al.[1―5]1) have calculated the finishing rolling tensile strength σb, yield strength σs, elongation δ of the alloying non-quenched and tempered steel with the covalent elec-1) Liu Z L, Lin C, Guo Y C. Theoretical calculation of the finishing rolling elongation in alloying non-quenched and tempered steel. Progress in Natural Science, in presstron number nA of the strongest bond in alloying phases and the smallest electron density difference ?ρ of phase interfaces. It is calculat…     

Prediction of mechanical properties of 50CrVA tempered steel strip for horn diaphragm based on BPANN

50CrVA cold-rolled spring steel strip was used to fabricate the diaphragm of the automotive horn. The material parameters which were taken into account in the design of the diaphragm involve elongation, elastic limit, Young’s modulus, yield strength and tensile strength. The tempering process was carried out in order to enable the diaphragm to possess the excellent mechanical properties, such as high elastic limit, high fatigue strength and perfect stress relaxation resistance. As a nonlinear information processing system, the backpropagation artificial neural network (BPANN) was applied to predict and simulate the relationship between the mechanical properties of the diaphragm and the tempering process parameters. Experimental results show that a BPANN with 3-8-5 architecture is capable of predicting the relationship between the mechanical properties of the diaphragm and the tempering temperature successfully and lays the profound foundations for optimizing the design of the diaphragm. BPANN simulation results show that the tempering temperature ranging from 380 to 420 °C contributes to enhancing the comprehensive mechanical properties of the diaphragm including high Young’s modulus, high elastic limit and high fatigue strength.     

Theoretical calculation of the finishing rolling impact work in non-quenched and tempered Si-Mn steel

Liu et al.[1―4] have given the calculation methods and general formulas of the finishing rolling tensile and yield strength of the non-quenched and tempered steel by using the electron structure parameters, and the calculated results agree well with the measured ones. In engineering technical standards, the σ b, σ s, δ and αk are always used simulta- neously. Therefore, the theoretical calculation neglecting δ and αk is not of integrity inboth learning and engineering. So the non-quench…