减压塔矩鞍填料等物件的腐蚀分析

<正> 一、前言近几年来,某炼油厂因原油酸值逐渐增加,设备腐蚀情况日趋严重,尤其是减压塔內的部件(例如矩鞍填料)腐蚀甚为严重。本文即对减压塔矩鞍填料(包括减一线、减二线和减三线矩鞍填料)、减三线格利希格栅填料、原始矩鞍填料及原始衬里板进行定量成分分析和腐蚀分析,并对水样及塔内腐蚀产物也进行了分析。减压塔填料作为减压     

高层建筑中转换层结构的影响因素与分析方法

阐述了高层建筑中转换层结构的功能、主要类型、影响因素及其优缺点,并对转换层结构体系目前常用的分析计算方法做了简单的介绍,同时对转换层结构的发展趋势进行了展望。     

海洋用结构钢在NaCl溶液中疲劳短裂纹的扩展

本文用海洋平台结构钢A537CL1的单边裂纹样品,在空气和3.5％ NaCl水溶液中进行了腐蚀疲劳短裂纹扩展实验,比较不同裂纹长度及环境介质对疲劳短裂纹扩展行为的影响。结果表明,在门槛值附近,对于相同的应力强度因子范围,短裂纹扩展速率比长裂纹扩展快。短裂纹扩展的门槛值随裂纹长度的减小而减小。与空气介质相比较,盐水对疲劳短裂纹扩展加速的程度远大于长裂纹。     

Fractal in Fatigue Fractography

Fracture profile roughnesses and fractal dimensionsof fracture traces were measured on a fatigued Ti-6Al-4Valloy.It is found that although fractal dimension can wellreflect the variation of fracture traces with the measuringunits,it is difficult to apply it to quantitative analysis offractured surfaces because of the dependence of the meas-ured profile roughness on the measuring units.Based onfractal concept.an alternative equationlgR_l(η)=lgR_o-(D-1)lgη was obtained.in which we intro-duced a parameter of intrinsic profile roughness to evalu-ate fracture profile roughness without restriction of themeasuring units employed.     

A Statistical Model of Quantitative Relationship between Striation Spacings and Fatigue Crack Growth Rates

Fatigue crack growth experiments were per-formed on A1 alloy LD 10 and Ti-6A1-4V alloy.Fatigue striation spacings and the deviationangles between the direction of micro-crackgrowth and that of macro-crack growth were quanti-tatively measured on fracture surface usingscanning electron microscope. A statistical model of the relationshipbetween striation spacings and fatigue crackpropagation rates was developed on the basisof a statistical analysis of the deviation angles,Good agreement between experimental resultsand theoretical results calculated with thepresent model was obtained.     

MICROMORPHOLOGY OF NEAR-THRESHOLD FATIGUE FRACTURE SURFACES

本文研究了LD10铝合金和Ti-6Al-4V合金近门槛值疲劳裂纹扩展的断口形貌。SEM观察表明:两种合金的近门槛值区域(1×10~(-7)-1×10~(-5)mm/cycle)的微观断口形貌均为循环解理刻面;在LD10铝合金中循环解理刻面多数呈锯齿型或梯田状,而在Ti-6Al-4V合金中主要为孤岛状循环解理刻面。 本文在实验观察的基础上,进一步阐明了近门槛值疲劳裂纹扩展机理。