Degradation of mechanical properties of Cr-Mo-V and 2.25Cr-1Mo steel components after long-term service at elevated temperatures

Polyvinyl chloride (PVC)/bamboo composites have been prepared and assessed for their use in interior and exterior load-bearing applications. PVC composites were formed by compounding PVC with different bamboo particle sizes and loadings. The mechanical properties of these composites were determined at both ambient and elevated temperatures and after long-term water soaking. Analysis revealed that bamboo incorporation improved the PVC composite flexural modulus which was also observed with dynamic mechanical-thermal analysis on heating composites toca.70°C. Addition of 25% and 50% bamboo particles increases flexural modulus by 80% with dependency on whether fine (<75 μm) or coarse (<1 mm) particles were used. On water soaking to saturation, composites had water weight uptakes of 10%, with reduced flexural properties obtained for all water-soaked composites. Nonetheless, the results of this study show that PVC/bamboo composites achieve the minimum flexural performance of ASTM D 6662, indicating potential for their use in exterior applications.

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Effect of Long Term Service at Elevated Temperatures on Mechanical Properties of Manaurite XM Reformer Tubes

Advances in Materials Science ◽

10.1515/adms-2016-0021 ◽

2016 ◽

Vol 16 (4) ◽

pp. 38-44

Author(s):

J. Łabanowski ◽

M. Jurkowski ◽

M. Landowski

Keyword(s):

Mechanical Properties ◽

Elevated Temperatures ◽

Cast Steel ◽

Internal Diameter ◽

Term Operation ◽

Static Tensile ◽

Different Shapes ◽

Reformer Tubes ◽

The Relationship

Abstract Microstructure transformations occur in the Manaurite XM cast steel tubes during long-term operation in the reformer furnace were revealed and described. The relationship between mechanical properties, an increase of internal diameter of the tube and microstructure degradation is discussed. Static tensile test was performed on two types of samples with different shapes. It has been shown differences in the results of tests and an explanation of this phenomenon.

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Mechanical Properties of X80 Grade UOE Pipe for Long-Term Exposure at Elevated Temperature

2004 International Pipeline Conference, Volumes 1, 2, and 3 ◽

10.1115/ipc2004-0416 ◽

2004 ◽

Author(s):

Ryuji Muraoka ◽

Mitsuhiro Okatsu ◽

Nobuyuki Ishikawa ◽

Shigeru Endo ◽

Shinichi Kakihara ◽

...

Keyword(s):

Mechanical Properties ◽

Elevated Temperatures ◽

Mechanical Tests ◽

Heat Treatments ◽

Oil Sand ◽

Operation Condition ◽

Long Time ◽

Simulated Condition ◽

Installation Cost

Recently, X80 grade UOE pipes have been planned to apply to steam injecting oil sand recovery systems to increase the volume of steam to be injected and lowering installation cost. The pipes for systems are subjected to high temperature for a long time, such as 350-C, for 20 years. Before real applications of the pipes, it is important to ensure the reliability of the pipes during and after long-term operations. In this study, in order to establish simulation conditions for 350-C × 20 years of operation, the change in microstructure and resulting mechanical properties of X80 grade pipes after a long-term exposure at elevated temperatures were investigated. Then, mechanical properties of the pipes subjected to the established simulated condition were examined. Change in the microstructure was quite small after exposure of 400-C and lower temperatures. Tensile strengths of the base metal and seam weld after up to 400-C of heat treatment can be arranged with the Larson-Miller parameter composed with temperature and holding time of the heat treatments. Therefore, heat treatments at 400-C for shorter than 20 years can be simulation conditions for the operation condition of the systems. As a result of mechanical tests simulating long-term exposure, satisfied performance of X80 grade pipes can be obtained.

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Microstructures and Mechanical Properties of NiAl+Mo In-Situ Eutectic Composites

MRS Proceedings ◽

10.1557/proc-194-147 ◽

1990 ◽

Vol 194 ◽

Cited By ~ 6

Author(s):

P. R. Subramanian ◽

M. G. Mendiratta ◽

D. B. Miracle ◽

D. M. Dimiduk

Keyword(s):

Mechanical Properties ◽

Solid Solution ◽

Room Temperature ◽

Composite System ◽

Elevated Temperatures ◽

Two Phase ◽

Structural Applications ◽

Temperature Fracture

AbstractThe quasibinary NiAI-Mo system exhibits a large two-phase field between NiAl and the terminal (Mo) solid solution, and offers the potential for producing in-situ eutectic composites for high-temperature structural applications. The phase stability of this composite system was experimentally evaluated, following long-term exposures at elevated temperatures. Bend strengths as a function of temperature and room-temperature fracture toughness data are presented for selected NiA1-Mo alloys, together with results from fractography observations.

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Behavior of Fiber Reinforced Plastic Materials in Chemical Service

CORROSION ◽

10.5006/0010-9312-25.4.157 ◽

1969 ◽

Vol 25 (4) ◽

pp. 157-167 ◽

Cited By ~ 31

Author(s):

R.F. REGESTER

Keyword(s):

Mechanical Properties ◽

Elevated Temperatures ◽

Glass Content ◽

Water Molecules ◽

Salt Solutions ◽

Fiber Reinforced Plastic ◽

Plastic Materials ◽

Reinforced Plastic ◽

Concentration Of Solutions ◽

Degradation Of Mechanical Properties

Abstract A study is made of the factors leading to the degradation in mechanical properties of glass reinforced polyester exposed to aggressive chemical environments such as H2SO4, HCl, and salt solutions at elevated temperatures. The penetration of water molecules, cations, and anions into the structure is described in terms of permeation rates as a function of time, temperature, pressure, glass content, resin type, and concentration of solutions. The permeation measurements are related to the diffusivity and solubility of the penetrating species in the structure and to the resultant degradation of mechanical properties.

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Ageing management in NPP. Effectiveness of the methods for control, examination and monitoring in relation to mechanisms of degradation of mechanical properties

MATEC Web of Conferences ◽

10.1051/matecconf/201814505015 ◽

2018 ◽

Vol 145 ◽

pp. 05015

Author(s):

Galya Dimova

Keyword(s):

Mechanical Properties ◽

Complex Analysis ◽

Life Extension ◽

Actual Condition ◽

Term Operation ◽

Additional Control ◽

Degradation Of Mechanical Properties ◽

Stage 1 ◽

Ageing Management

This paper describes ageing management activities for Long Term Operation (LTO) of components of Kozloduy NPP EAD. The stages of LTO Project are: Stage 1 - implementing a comprehensive assessment of the actual condition of the equipment; Stage 2 - providing of a Complex Analysis; Stage 3 – licensing of Plant Life Extension (PLEX) for long-term operation (LTO). The main activities are assessment of actual condition of the equipment and building; review of methods for control (non-destructive), examination and monitoring; assessment of effectiveness of methods; necessity of additional control/ examination/ service. The paper describes some mechanisms of degradation of mechanical properties, methods for control and criterions for their effectiveness.

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