不同冷轧状态的ELC-BH钢板连续退火再结晶规律

对不同压力率的ELC-BH钢板进行了连续退火试验。研究结果发现，随着冷轧压下率增加和冷轧板厚度减薄，ELC-BH钢板的连续退火再结晶过程提前并缩短，晶粒长达过程相对延长，这对于不同厚度产品的生产工艺调整十分重要。     

多点位控制压边数值模拟研究

板料冲压成形的主要缺陷是起皱和撕裂 ,当模具的几何形状确定后 ,压边力是关键的成形控制参数 ,它不仅是凸模行程或时间的函数 ,还应随压边位置的不同而变化。确定拉深过程中板料各部位所需压边力的变化规律 ,可实现压边力的优化控制 ,对复杂拉深件如汽车覆盖件的成形尤为有利。该文以非轴对称抛物面车灯反光罩为例 ,采用DYNAFORM软件对其成形过程进行了数值模拟 ,比较了均布控制压边力和多点位控制压边力对成形的影响     

AZ91D摩托车发动机壳体压铸模设计

针对摩托车发动机壳体的结构特点及工艺要求,介绍了一种切实可行的压铸模设计方案。该压铸模选择最大截面为分型面,浇注系统设计时采用FLOW-3D仿真软件进行模拟填充,用模温机及循环的冷却水控制模具温度,设置斜销式抽芯机构。经生产实践证明,铸件达到了图纸的各项要求,并已进行小批量生产。     

表面渗铬T8钢中碳迁移的热力学分析

采用双辉等离子渗铬技术，对T8钢进行了900℃温度表面渗铬合金化；使用GDA750．测量了试样渗铬合金层中Fe、Cr和C等元素的浓度分布。通过热力学分析计算，研究了渗铬合金化层形成过程中碳迁移机理和规律。指出驱动碳迁移的动力是碳的括度梯度，并推导出富碳区碳质量分数随铬质量分数变化的数学关系式：w(C）=0．8 0.3536w(Cr)。计算结果与试验结果相当吻合。     

Resistance of Mo-bearing stainless steels and Mo-bearing stainless-steel coating to naphthenic acid corrosion and erosion-corrosion

Naphthenic acid corrosion (NAC) and erosion-corrosion (NAEC) behavior of Mo-bearing (0-7.0 wt.%) stainless steels have been investigated in laboratory to evaluate the essential role of Mo on their NAC and NAEC resistance. The NAC and NAEC resistance of a high-velocity-oxygen-fuel (HVOF) thermal sprayed Mo-bearing stainless-steel coating was also investigated in both laboratory and an oil refinery. It was found that increasing the Mo content remarkably enhanced the NAC and NAEC resistance of stainless steels. The Mo-rich areas or phases in the steels played an importance role in resisting the NAEC. The HVOF coating showed excellent NAC and NAEC resistance in laboratory tests. The 700-day field test in an oil refinery revealed that the coating can effectively prevent the carbon-steel substrate from erosion-corrosion during long-term exposure in oil-refining environment. The corresponding NAC and NAEC mechanisms of the stainless steels and the beneficial role of Mo were discussed by taking account of inherent susceptibility of metal elements to corrosion, possible effects of Mo on surface films, and Mo-induced change in microstructure and microhardness.     

Thermal expansion anomaly and spontaneous magnetostriction of Dy2AlFe14Mn2 compound

The structure and magnetic properties of Dy₂AlFe₁₄Mn₂ compound were investigated by X-ray diffractometry and magnetization measurements. Dy₂AlFe₁₄Mn₂ compound has a hexagonal Th₂Ni₁₇-type structure. Zero thermal expansion and negative thermal expansion were found in Dy₂AlFe₁₄Mn₂ compound in the temperature range from 184 to 264 K, and from 264 to 383 K, respectively, by X-ray dilatometry. The spontaneous magnetostrictive deformations from 104 to 400 K were calculated. The results show that the spontaneous volume magnetostrictive deformation increases firstly with increasing temperature, and then decreases with further increasing temperature.     

WCp增强钢基表层复合材料的两体磨粒磨损性能

在室温条件下,选用销盘磨粒磨损试验机,绿碳化硅磨料,研究增强相WC颗粒直径对WCp增强钢基表层复合材料磨损性能的影响,以正火ZG45作为标样,计算相对耐磨性ε值.研究结果表明,WCp增强钢基表层复合材料相对于正火ZG45的相对耐磨性ε值,随其增强相WC颗粒直径的变小而降低,当增强相WC颗粒直径大于150μm时,相对耐磨性ε值高达40左右,而当增强相WC颗粒直径小于100μm时,相对耐磨性ε值降低到5以下.     

FV520(B)钢时效组织和力学性能分析

通过透射电镜、电子拉伸、示波冲击试验,分析了马氏体沉淀硬化不锈钢FV520(B)850℃油淬后分别在560、600和630℃时效后的组织和力学性能。结果表明,淬火态FV520(B)钢560℃和600℃时效处理后,组织均为过时效马氏体+残余奥氏体,但细微组织有较大的差别,630℃时效处理后,组织为过时效马氏体+马氏体+ 残余奥氏体;560℃时效后强度最高;三种时效温度下,FV520(B)均具有较高的冲击韧度,600℃时效后冲击韧度最高;时效温度对FY520(B)冲击韧度的影响主要决定于其对塑性变形功(Apl)的影响。     

基于VERICUT的虚拟龙门加工中心建模和仿真关键技术研究

为减少零部件试切,检验数控工艺合理性,构建了虚拟龙门加工中心。研究了龙门加工中心运动,阐述了侧面铣头运动由旋转中心和换刀点控制,提出了虚拟机床侧面铣削运动构建方法,可实现各角度侧面铣。搭建了虚拟加工环境,通过零件仿真加工,完成了零件顶面及4个侧面的铣削加工,验证了数控代码的正确性,检验了数控工艺合理性,减少了零件试切,缩短了开发周期,仿真结果表明虚拟龙门加工中心的正确性。     

基于MATLAB的节流阀调速液压回路计算机仿真

以进油节流阀调速液压回路为例,建立了描述液压调速回路动态特性的集中参数数学模型,给出了在MATLAB环境下建立其仿真模型的方法.应用计算机仿真的方法,研究了节流阀开口度的不同和油液体积弹性模量值的改变对进油节流调速回路动态特性的影响,给出了仿真结果.