Evaluation of viscosity properties of plastically deformed gas pipeline steels

Abstract

In completing important national security issues of ensure the fuel and energy complex of raw materials an
important role play natural gas pipelines. Their performance provides a reliable state of pipes that with increasing
the service life that is getting worse. Considering that most of the gas pipes is in operation 30 ... 40 years old, the
material lends itself to their intensive degradation. Overload, which may be due to the shift of the surrounding soil,
excessive bending of the pipe laying at work on a curved road, fall pipes, etc., further worsen the condition of the
pipes. These factors form on separate pipelines plastically deformed zone. Over time, they tend to develop into a
crack, having the ability to develop and create emergencies. Therefore, the evaluation of the toughness properties of
plastically deformed steel pipelines can be no doubt in their relevance.
The results of experimental studies determining the mechanical properties of plastically deformed during overload
pipe steels. Recession toughness of steels caused the lowering part of the crack propagation. Increase of preliminary
plastic deformation of steel samples X52 is the steepness of the decline curves of cold brittleness.
The prospects of using electrochemical methods for the development of non-destructive testing method toughness
and static fracture (K1C) previously plastically deformed pipe steels are shown. Compression deformation of
the magnitude of the strain 30% operated for over thirty years of pipe steel X52 almost has no effect on the electrochemical
performance of the material. This is due to the depletion of the reserve of plasticity and considerable damage
to the degraded metal.