Influence of the Long-Term Operation of Gas Pipelines on the Cyclic Crack-Growth Resistance of 17G1S Steel

Abstract A maintenance concept of performance based maintenance (PBM) has been proposed by the current author. According to the PBM concept, inspection results are considered in determining the next inspection schedule. In this study, this concept was applied to fatigue degradation for stainless steel components in the pressurized water reactor (PWR) primary water environment. It is possible to estimate the fatigue life for the PWR water environment from that obtained in an air environment and the parameter Fen, which represents the ratio of the fatigue life in the air and PWR water environments. It was shown that the fatigue life prediction using Fen can be replaced by the crack growth analysis using the growth rate for the PWR water environment. Then, the crack growth was predicted for a thermal loading assuming the growth occurred in the PWR water environment. It was shown that the duration until the next inspection could be optimized based on the inspection results together with the crack growth curve. A long term operation before the inspection resulted in a longer duration until the next inspection.

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Impact of Long-Term Operation on the Reliability and Durability of Transit Gas Pipelines

Strojnícky casopis – Journal of Mechanical Engineering ◽

10.2478/scjme-2020-0011 ◽

2020 ◽

Vol 70 (1) ◽

pp. 115-126

Author(s):

Okipnyi Igor ◽

Poberezhny Lyubomyr ◽

Zapukhliak Vasyl ◽

Hrytsanchuk Andrii ◽

Poberezhna Liubov ◽

...

Keyword(s):

Mechanical Properties ◽

Corrosion Fatigue ◽

Static Loading ◽

Physical And Mechanical Properties ◽

Fatigue Tests ◽

Gas Pipelines ◽

Term Operation ◽

Full Capacity ◽

Corrosive Environments

AbstractCorrosion and corrosion-fatigue tests of the material of the pipeline, which was in operation for 41 years. It has been shown that prolonged operation reduces the parameters of resistance to fatigue and prolonged static loading in corrosive environments. It was established that the degradation of physical and mechanical properties is insignificant, Ukraine’s main gas pipelines are ready to operate at full capacity provided that timely monitoring measures are carried out.

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Effect of Long Term Operation on Degradation of Material of Main Gas Pipelines

Materials Science Forum ◽

10.4028/www.scientific.net/msf.782.279 ◽

2014 ◽

Vol 782 ◽

pp. 279-283 ◽

Cited By ~ 12

Author(s):

Pavlo Maruschak ◽

Roman Bishchak ◽

Igor Konovalenko ◽

Abdellah Menou ◽

Janette Brezinová

Keyword(s):

Digital Images ◽

Main Pipeline ◽

Gas Pipelines ◽

Indentation Method ◽

Term Operation ◽

Metal Damage

The mechanisms of metal damage in the pipe of the main pipeline are investigated, the main reasons for their appearance are found and analysed. The main results are obtained by joint use of metallography, indentation, method for processing and analysis of digital images.

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Improving Subcritical Crack Growth Resistance for Alumina Glass Dental Composite

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.280-283.1623 ◽

2007 ◽

Vol 280-283 ◽

pp. 1623-1628

Author(s):

Q. Zhu ◽

G. de With

Keyword(s):

Crack Growth ◽

Subcritical Crack Growth ◽

Glass Network ◽

Nitrogen Addition ◽

Crack Growth Resistance ◽

Dental Composite ◽

Oxide Glass ◽

Dental Composites ◽

Glass Composites

Abstract. The improvement of subcritical crack growth (SCG) resistance for alumina glass dental composites was explored in this study. The addition of nitrogen to the glass phases in the composite was found to increase the SCG resistance, where the SCG exponent n increases from 22 for the oxide glass composites to 30 for the composites containing 0.5 mol% nitrogen in the glass phases. The improvement was tentatively attributed to the nitrogen addition, which makes the glass network stronger through forming the non-flexible Si-N bonds and thus inhibits the hydrolysis reactions under the SCG conditions. Analyses demonstrated that the increase of the n value from 22 to 30 offers the potential to greatly extend the lifetime and improve the long-term reliability for the alumina glass dental composites.

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