房地产楼盘上市推广策划方案.ppt

Ref. p. 6] 1 Introduction 1
1 Introduction
K. YAGI, G. MERCKLING, T.–U. KERN
General remarks
To utilize energy resources efficiently and preserve the global environment, efforts are being made to
raise the temperature at which high-temperature equipment is used at power and chemical plants. As a
result, the conditions to which the ponents of these plants are exposed have e much
more demanding. ponents have been developed that endure these extreme conditions and
some of them are ing into use. It is therefore necessary to ensure the effective and safe use of
these materials, to gain a full understanding of the characteristics of the new ponents, to
evaluate their strengths, and to predict their life with greater accuracy. On the other hand, many of the
world’s high-temperature plants were constructed as long ago as the 1970s and have deteriorated
markedly with age. These aged plants are sometimes used under operating conditions different from those
planned at the time of their construction. Therefore, the key issue is to be aware of the changes that take
place in materials for ponents over time and to predict their remaining life with high
accuracy.
With regard to the prediction of the life of high temperature structural materials, the evaluation of their
deterioration with time and the prediction of the remaining life of aged materials, it is essential to have a
full knowledge of the characteristics of these materials and to be aware of the existence of material data
that is a source of that knowledge. Creep characteristics are typical properties of high-temperature
structural materials. Because the creep characteristics of structural materials in high-temperature plants
are understood to be important in the design of boilers and pressure vessels, creep tests have been actively
conducted since the 1930s [1, 2]. Creep data have been systematically obtained and published in the
United States and European countries such