钢种、轨型及生产工艺对钢轨矫后残余应力的影响

研究了不同钢种（U74、U71Mn、BnbRE）、不同轨型（50kg/m、60kg/m、75kg/m）及在不同生产工艺下，钢轨矫后残余应力值的变化。结果表明，不同钢种生产的同轨型钢轨，矫后钢轨轨底中心部位残余应力值随着钢轨强度级别的增加而增加，同钢种、不同轨型的钢轨矫后轨底中心残余应值随着钢轨单位长度质量的增加而增加，同钢种、同轨型的钢轨随着矫直力的增加，钢轨矫后轨底中心残余应力值也增加。而钢轨终轧温度的高低，矫前原始弯曲度的大小（Y轴方向）在现有生产工艺条件下，对钢轨矫后轨底中心残余应力值无明显影响。     

表面完整性对马氏体不锈钢疲劳性能的影响

研究了马氏体不锈钢表面喷丸强化后表面粗糙度，表面形貌，表面残余应力和表面层残余压应力场等表面完整性的变化及其对疲劳性能的影响，结果表明：马氏体不锈钢对表面粗糙度比较敏感，经喷丸强化后产生的残余压应力有利于提高疲劳寿命，且采用低喷丸强度时对疲劳性能更加有利。     

球化处理中残留碳化物的作用

研究了三种钢在缓冷法球化处理中残留碳化物对球化的影响。结果表明,残留碳化物形貌和数目是影响球化的两个关键因素。残留碳化物只有以点状存在才能使碳化物球化,其数目越多,球化效果越好。通过金相观察和热力学分析,证明了点状残留碳化物在球化中的作用是使共析转变中碳化物能以短棒状和颗粒状析出,以便为随后的碳化物球化长大做好组织准备。     

热沉影响钛合金薄板焊接残余应力的试验分析

采用切条应力释放法测量了钛合金TC4薄板常规钨极氩弧焊(GTAW)和动态控制低应力无变形GTAW对接试件中的纵向残余应力和纵向残余塑性应变的分布。测量结果表明,钛合金常规GTAW缝中残余拉应力峰值小于其母材屈服强度,焊缝附近存在残余压缩塑性应变;动态控制低应力无变形GTAW焊技术中热沉的冷却作用使得热源与热沉之间的高温金属承受强烈的拉伸作用,产生拉伸塑性变形,部分抵消了焊接过程中已产生的缩短的塑性变形,使得试件中纵向残余塑性应变减小,焊接残余拉应力峰值降低,残余压应力水平降低。切条应力释放法是一种简便有效的薄板焊后残余应力测量方法,能够满足工程应用的精度要求。     

THEORY DEPOSITION MODEL AND INFLUENCING FACTORS DURING PROCESS OF PREPARING MICRO-LAYER LAMINATE BY EBPVD

This paper briefly introduces the characteristics of electron beam physical vapor deposition (EBPVD) technique and the whole process of preparing micro-layer composite laminate. And several major influencing factors are presented and discussed. It was found that residual gas pressure should be low enough to guarantee the unobstructed transportation of vapor steam and electron beam; the evaporation method and evaporation speed are up to the different vapor pressure deficit of compositions of raw materials; and the substrate temperature could have great influence on the microstructure of the micro-layer laminates.     

W18Cr4V高速钢激光相变强化层的残余应力

利用Ｘ射线衍射法对Ｗ１８Ｃｒ４Ｖ高速钢激光相变强化层的残余应力进行了测定和分析。试验结果表明，相变强化层表面的残余应力为压应力，内部为拉应力，近似按正弦函数分布。其大小和分布状态随工艺参数的变化而改变。当改变工艺参数使表面熔化时，表面为拉应力。     

爆炸法消除焊接残余应力对焊接接头力学性能的影响

采用70mm厚16MnJ对接试板,研究了焊后和爆炸消除应力后两种状态焊接接头冷弯、拉伸、硬度、冲击和疲劳等力学性能的变化。结果表明:爆炸法消除焊接应力不会降低焊接接头的上述力学性能。     

Effects of coating thickness and residual stresses on the bond strength of ASTM C633-79 thermal spray coating test specimens

Wire-arc-sprayed nickel-aluminum is widely used in the aircraft industry for dimensional restoration of worn parts and as a bond coat for thermal barrier coatings and other top coats. Some repair applications require thick coatings, which often result in lower bond strength. A mechanism being investigated to ex-plain this decrease in bond strength is the free edge effect, which includes both coating residual stresses and coating thickness. The layer-removal method was used to determine experimentally the residual stresses in wire-arc-sprayed nickel-aluminum coatings of different thicknesses. Bond strength evalu-ations were performed using an improved ASTM C 633-79 test specimen. Finite-element analysis and fracture mechanics were used to investigate the effects of coating thickness and residual stress state on coating bond strength.     

TiN涂层性能的分析与测定

测定并分析了用PCVD法获得的TiN涂层内的残余应力、涂层的抗变形性以及涂层的耐磨性。实验结果表明,TiN涂层内有残余应应力存在,在一定的变形力作用下,涂层将发生脆性断裂,TiN涂层的耐磨性是45°淬火钢的24倍。TiN涂层这些特性为它的应用奠定了基础。