研究了正火次数和保温时间对EA4T钢调质组织的影响,结果表明:晶粒尺寸、晶粒度和金相组织与正火次数无关,而与保温温度有直接关系.EA4T钢采用900℃保温4h出炉风冷的一次正火工艺后,是否进行850℃保温4h出炉风冷的二次正火工艺,对调质晶粒度和金相组织无影响.

以B型地铁铝合金车体为研究对象，建立一节Tc车的有限元模型，结合实际工况，对一节整备车辆在垂向AW3纵向施加1000 kN压缩力的工况下进行仿真计算，查看Ⅰ端牵引梁车钩安装区域的应力随着不同加载方式（rigid单元或接触单元）的变化规律，并对比分析。

A nickel layer on the surface of polyurethane foam was prepared by electroless plating and electro-deposition process.The main factors affecting the thickness and quality of the layer such as pH value,temperature,current density were explored.Optical microscopy,scanning electron microscope and energy dispersive spectrometer were used to observe the surface morphologies,cross-section microstructure and composition of electroplated nickel layer.Experiment results show that the thickest coating obtained at pH = 4.2 is 76 μm.The coating thickness increases with increasing current density with scorched coating appeared when the current density is 11.8 A/dm2,and the optimal current density is 9.6 A/dm2.The temperature to obtain the thickest coating is 60℃ with a coating of 95 μm.Deposition thickness increases with deposit time increase.In the optimized deposition conditions,a bright,uniform and flawless nickel coating can be obtained.