Creep and long-term strength of niobium alloy VN-2 at high temperatures

1970 ◽  
Vol 2 (3) ◽  
pp. 235-238
Author(s):  
V. V. Krivenyuk ◽  
I. V. Makovetskii
Keyword(s):  
High Temperatures ◽  
Niobium Alloy ◽  
Term Strength

PE-RT: A New Class of Polyethylene for Industrial Pipes

2006 ◽  
Author(s):  
Detlef Schramm
Keyword(s):  
Molecular Structure ◽  
High Temperature ◽  
High Temperatures ◽  
Power Plants ◽  
Cold Water ◽  
Industrial Applications ◽  
Pipe Production ◽  
Term Strength ◽  
Temperature Resistance

The development of a new family of PE materials with significantly improved processability and long term strength at high temperatures is discussed. These polymers form the basis for a new ISO class of polyethylene materials: PE-RT (Polyethylene of Raised Temperature resistance) for hot and cold water as well as industrial pipe applications. These materials have a unique molecular structure and crystalline microstructure, which provides excellent Long Term Hydrostatic Strength at high temperature without crosslinking the material. PE-RT type materials are successfully used in domestic hot and cold water piping systems for most applications. The easy processing and outstanding material properties made these resins also attractive for use in many industrial applications, where larger dimensions are required and regular Polyethylene cannot be used or has temperature limitations. They also compete against high end engineering plastics, offering significant cost savings. These materials provide significant process advantages to the converters, allowing high line speed pipe production and providing excellent flexibility and ease of installation for the application. A recently developed PE-RT type material offers still higher long-term strength at high temperature and further improved processability. This combination makes this resin particularly suitable for high temperature applications. An example of the latter is in larger diameter cooling water pipes in power plants. Pipes based on these materials can be connected via heat welding or by the use of mechanical fittings. Furthermore this material can be used in industrial applications, were traditional Polyethylene is limited by the temperature resistance and metallic materials suffer from corrosion. The excellent weldability of these materials provides various opportunities to connect also larger dimensions in industrial applications. Another example of this is the use in multi-layer structured oil pipelines on-shore and off-shore. This paper presents the material science and product design concepts that govern the high long-term hydrostatic strength at high temperatures. By controlling the molecular structure, the melt rheology and solid state properties can be influenced. This results in a unique balance of processability and hydrostatic strength. Further discussed are the product features and benefits of PE-RT materials. The paper shows examples of the application range for this type of products, using applications in the domestic pipes market as a reference study.

Subcritical Crack Growth and Long-Term Strength in Rock and High-Strength and Ultra Low-Permeability Concrete

2009 ◽  
Vol 58 (6) ◽  
pp. 525-532 ◽  
Author(s):  
Yoshitaka NARA ◽  
Masafumi TAKADA ◽  
Daisuke MORI ◽  
Hitoshi OWADA ◽  
Tetsuro YONEDA ◽  
...  
Keyword(s):  
Crack Growth ◽  
Subcritical Crack Growth ◽  
High Strength ◽  
Low Permeability ◽  
Term Strength

Long-term strength retrogression of silica-enriched oil well cement: A comprehensive multi-approach analysis

2021 ◽  
Vol 144 ◽  
pp. 106424 ◽  
Author(s):  
Xueyu Pang ◽  
Jiankun Qin ◽  
Lijun Sun ◽  
Ge Zhang ◽  
Honglu Wang
Keyword(s):  
Oil Well ◽  
Term Strength ◽  
Oil Well Cement ◽  
Well Cement
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