Electronic and microscopic researches of dislocation structure of metal near crack top

International Workshop "Advanced Technologies in Material Science, Mechanical and Automation Engineering – MIP: Engineering – 2019"

材料科学;机械制造;原子能学

Nasibullina, O.A.^1 ; Tyusenkov, A.S.^1

Ufa State Petroleum Technological University, Ufa

450062, Russia^1

关键词: Cathode protection;    Corrosion cracks;    Dislocation structures;    Multiple crack;    Outer surface;    Single crack;    Stress crack corrosion;    X-70 steels;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/537/2/022023/pdf
DOI  :  10.1088/1757-899X/537/2/022023

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The most important element of fuel and energy complex is the system of the main pipelines for transport of gas, oil and products of their processing. On a surface of the main pipes in the presence of cathode protection there can be corrosion cracks. It is connected with simultaneous influence of two factors - soil electrolytes and the stretching tension. One of the most dangerous types of destruction of main gas pipelines is stress-crack corrosion (SCC). Defects on an outer surface of a pipe are shown in the form of single cracks or their system focused generally along the forming pipe. In work studying of the multiple cracks formed on the main gas pipeline under the exfoliated isolation is presented. Researches were conducted on a sample of X70 steel of the Japanese production which is selected from a focal zone of destruction of the main gas pipeline. On a sample there were cracks, characteristic of corrosion cracking. For the proof that cracks had corrosion and mechanical origin electronic and microscopic researches of dislocation structure of metal near crack top were conducted by means of a method thin foils and also the diffraction pattern of the site with a crack is studied.