原位红外光谱研究白油的热氧老化过程

采用原位红外研究了白油在氧气中的热氧老化过程,并通过热分析动力学研究了其热氧老化的反应速率及反应机理。研究表明,白油在热氧老化过程中主要发生断链和氧化反应。白油的断链为一级反应。在白油中加入多种不同类型添加剂,可以发现,白油的分解、断链和氧化均有不同程度的减弱。

Influence of the Main Technological Variables of Cyclical Mechanic-Thermal Processing on the Strain Hardening of Steel Parts

The main objective of the present work was to determine the influence of the most important technological variables of CMTP （cyclical mechanic-thermal processing） on the strain hardening in the surface layers of steel parts. For this, it was designed a full factorial plan at two levels of five independent variables that include the whole processing in two and three cycles, the cold-forming degree and force during the plastic deformation （burnishing）, and the temperature and time at the given temperature during the aging. Each cycle is composed of plastic deformation at room temperature plus aging. As dependent variables, the degree and penetration depth of strain hardening were evaluated. Based on the appropriately used set of experimental data, it had been fitted an exponential model for each dependent variables and also a two-degree polynomial fitting of in-depth evolution of microhardness profile was obtained. The amount of cycles and the cold-forming degree are the technological variables of CMTP that influence the most on strain hardening, although other variables also are significant. The microhardness profile highlights that during the CMTP, the strain hardening decreases from the outer bound to the transition zone of the surface layers, where it disappears.

耐高温涂料

对于从事涂料的研究人员，置于高温环境下物体的表面涂装是存在问题最多且极富有挑战性的应用领域之一。在许多应用领域，热老化造成的后果档，如：在化学品和石油化学品加工设备，矿业和气体制造，导弹及飞机等应用领域。由于工作环境经受的温度非常高，所以涂料能否具有很好的耐热性是非常重要的。烟囱，锅炉等类似设备的受热表面需要涂装高档涂料；以抗耐腐蚀性烟气，循环加热操作，热膨胀及大气化老化等因素的影响。