A3钢焊缝区在酸性介质中氢致腐蚀裂开行为的研究

本文应用慢应变速率拉伸试验法、金相和扫描电镜技术研究了带焊缝的A3钢试样在会缓蚀剂的盐酸溶液中的氢致腐蚀裂开行为。结果表明,在酸液中带焊缝试样的断裂均发生在热影响区;带焊缝A3钢试样的脆断敏感程度显著高于其母材;缓蚀剂的添加可以较大程度地改变带焊缝材料的脆断敏感性。     

Intelligent optimal control for lead-zinc sintering process state

The intelligent integrated predictive model of synthetical permeability was established using the fuzzy classifier to combine the time sequence predictive model with the craftwork parameter predictive model. Then, the estimation model of bum-through point（BTP） based on pipe stress point（PSP） method and the predictive model of BTP were proposed. The optimal control of permeability and heat states was implemented by using the fuzzy expert controller with self-studying mechanism. The application of the intelligent control technique suppresses 17% of the fluctuation of synthetical permeability and 12% of the fluctuation of BTP, stabilizes the output and quality of sinter and settles the basis for the optimization of output and quality of sintering process.     

Dependence of dielectric properties on BT particle size in EP/BT composites

The polymer-ceramic composites of epoxy resin (EP) and barium titanate (BT) were prepared.BT powders of different BT particle sizes from 100 nm to 1 μm were used in the preparation.The dielectric properties, such as dielectric constant, dielectric loss and electrical breakdown strength, of the EP/BT composites were studied.The morphology of the composites was characterized by the means of scanning electron microscopy (SEM).The results show that the dielectric constant of the composites is much higher than the epoxy matrix at frequency range from 1 kHz to 10 MHz, and it is also obviously dependent on the size of BT particles.The electrical breakdown strength of the composites decreases with the increase of the BT content.The dependence of electrical breakdown strength on BT particle sizes was also discussed.     

异形坯连铸坯壳应力与鼓肚变形分析

坯壳应力引起的鼓肚变形是影响铸坯质量的重要因素,为防止过大的鼓肚变形,依据湍动能理论、热流传递理论和粘弹性理论,建立了异形坯三维热-力耦合模型,开发了鼓肚分析软件,从而避免了漏钢事故的发生.该模型将温度场和应力场的计算相互耦合,交替进行.结果表明:异形坯截面最危险点位于腹板中部,其次为翼板中点,在两者相结合的圆角部,由于凝固坯壳比较薄,其应力值也比较大;当坯壳厚度小于20 mm时,两点的鼓肚变形量将分别超过其极限变形量,铸坯出结晶器时必然发生漏钢事故.该模型通过预测坯壳应力和鼓肚变形量为现场安全生产提供了理论依据.     

La在KCl-NaCl和LaCl_3-KCl-NaCl熔体中的溶解行为SCIEI

本文利用透明槽技术、电化学循环V-A法及量子化学EHMO三种方法,研究了La在KCl-NaCl(1:1mol)及LaCl_3-KCl-NaCl熔体中的溶解行为。初步认为:溶解在KCl-NaCl熔体中的La是以中性金属状态存在。在LaCl_3-KCl-NaCl熔体中,溶解的La与La^(3+)作用生成低价La^(2+)离子,La^(2+)又与周围的La^(3+)作用形成原子簇离子La_m^(n+)赋存于熔体之中。     

小波分析与漏磁检测信号处理

详细介绍了小波分析的基本理论,并将其引入到钢管漏磁探伤信号的分析中,可以去除噪声、压缩数据和检测奇异性,而且为缺陷的定性和定量分析提供了新的判定方法.     

水基淬火液用于汽车轴管零件的淬火冷却

在分析几种淬火液的基础上 ,选用冷却速度与快速淬火油相近的FEROQUENCH 2 0 0 0淬火液用于轴管淬火冷却 ,淬火后的轴管彻底消除了淬火裂纹 ,而且改善该零件热处理后的力学性能。     

二维有限元自适应网格规划生成

在设计基准点、沿指定曲线等网格加密生成方式的基础上，根据二维区域几何特征和分析对象物理特性估计，通过选择合适的网格加密生成方式，作用于分析对象上，规划构造有限元自适应网格单元尺寸信息场，进而提出基于Delaunay部分的动态节点一单元一体化算法，实现几何特征和物理特性整体自适应的有限元网格自动生成。算例表明此方法可生成高质量、符合分析要求的有限元自适应网格。     

精铸工艺在汽车零部件制造中的应用与发展

阐述精铸行业发展现状及中国精铸业在品质与技术方面与国外同行的差距 ,通过对精铸工艺技术延伸性的分析 ,就精铸工艺在汽车零部件制造方面的应用与发展趋势进行分析。最后介绍东风精铸在缩小与国外同行的差距及致力于提升东风精铸整体水平方面所做的努力。