Structural Degradation of the Welded Joint of the Gas Main after a Long-Term Operation in Sub-Acid Soil

The authors investigated the main regularities in the structural and mechanical degradation of steel and a welded joint of the "Soyuz" gas main in operation. It is established that the defect accumulation kinetics in welds are determined both by technological disruptions in their manufacture and by hydrogenation of the weld during a long operating time. A weakening of the mechanical properties of the weld after a prolonged operation is shown, which in some cases led to the appearance of cracks and fracture of the gas main

Structural Degradation of the Welded Joint of the Gas Main after a Long-Term Operation in Sub-Acid Soil

The authors investigated the main regularities in the structural and mechanical degradation of steel and a welded joint of the "Soyuz" gas main in operation. It is established that the defect accumulation kinetics in welds are determined both by technological disruptions in their manufacture and by hydrogenation of the weld during a long operating time. A weakening of the mechanical properties of the weld after a prolonged operation is shown, which in some cases led to the appearance of cracks and fracture of the gas main

Influence of stress concentrator shape and testing temperature on impact fracture regularities of pipeline steel

The structure and impact toughness of the pipeline 17Mn1Si steel have been studied. The main attention was paid to the analysis of various conditions of stress concentration under dynamic loadings. The process of strain localization with increasing stress state stiffness at the tip of the concentrator with decreasing testing temperature was investigated. Impact loading diagrams for specimens with various stress concentrator shapes were registered and analyzed

Analysis of Fracture Characteristic of a Gas Main Pipe on the Basis of the Additive Mathematical Model of the Cyclic Random Process and Polynomial Function

The use of a mathematical model to describe the phenomenon of dynamic fracture of the gas main in a broad range of crack propagation rates is substantiated, taking into account the stochastic and cyclic nature of this process. Particular attention is paid to the reliability of the proposed approach, which is evaluated based on comparison with known natural experiments

Damage tolerance analysis of continuous caster roll containing a circumferential semi-elliptical crack

Проведено аналіз існуючих методів прогнозування залишкового ресурсу металургійного обладнання. Оцінено тримку здатність ролика машини безперервного лиття заготовок із напівеліптичною поверхневою тріщиною на основі використання підходів SINTAP з урахуванням розкиду розмірів тріщини, в'язкості руйнування, характеристик механічних властивостей матеріалу та величини прикладеного навантаження через випадкові змінні з відповідними функціями розподілу. Одержані результати свідчать, що метод може бути рекомендовано для практичного використання.The procedure for damage tolerance analysis of metallurgical equipment is presented and illustrated by a case study on caster roll. The scheme is based on the recently developed prosedure SINTAP taking into account the scatter of crack’s geometry, fracture toughness, material properties and applied loadings as random variables with corresponding distribution functions. The results show that the method can be used in practice

Influence of ion-beam treatment on structure and defor-mation resistance of 12Cr1MoV steel under static, cyclic and dynamic loading

Features of modification of structure and properties of 12Cr1MoV steel subjected to ion-beam irradiation by zirconium ion beam have been investigated with the use of optical and electron microscopy, and microhardness measurement. It was shown that after the treat-ment the modification occurs across the entire cross-section of specimens with the thickness of 1 mm. Changes in mechanical properties of these specimens under static, cyclic and impact loading were interpreted in terms of identified structure modifications

Reasons for crack nucleation in welded joints of main gas-pipelines after a long-term operation

A crack of operational origin in the welded joint of the main gas pipeline is analyzed. The reasons for its nucleation and impact on technological microdefects that were formed earlier during the welding are found. Micromechanisms and stages of nucleation and propagation of the crack are investigated

Influence of stress concentrator shape and testing temperature on impact fracture regularities of pipeline steel

The structure and impact toughness of the pipeline 17Mn1Si steel have been studied. The main attention was paid to the analysis of various conditions of stress concentration under dynamic loadings. The process of strain localization with increasing stress state stiffness at the tip of the concentrator with decreasing testing temperature was investigated. Impact loading diagrams for specimens with various stress concentrator shapes were registered and analyzed

РОЛЬ МЕДИЧНОЇ СЕСТРИ У ПОПЕРЕДЖЕННІ ВПЛИВУ МЕТЕОРОЛОГІЧНИХ ФАКТОРІВ НА СТАН ПАЦІЄНТІВ З ГІПЕРТОНІЧНОЮ ХВОРОБОЮ

This article provides an assessment of the impact of climatic and meteorological factors on the patients with hypertension and establishes the role of the nurse in the prevention of complications.It was established that the background temperature fluctuations of air, dynamic reduction in rainfall is the growing number of inpatient cardiac patient profile. Increased incidence of hypertension and complications were associated with the temperature of the air, the patient's age and time of day.A plan of nursing staff for the prevention of hypertensive crises and other complications of hypertension include: 1) formation of risk group among patients with significant fluctuations in blood pressure, especially at night time; 2) development of daily journal for vital parameters registration (body temperature, blood pressure, pulse); 3) training and control of accuracy of vital indicators registration; 4) educational work about risk factors and prevention of hypertension and its complications.У статті проведено оцінку впливу природно-кліматичних та метеорологічних факторів на перебіг захворювання у пацієнтів із гіпертонічною хворобою та встановлено роль медичної сестри у профілактиці розвитку ускладнень.Встановлено, що на фоні коливання температури атмосферного повітря, динамічного зменшення кількості опадів відбувається зростання кількості стаціонарних пацієнтів кардіологічного профілю. Збільшення захворюваності та ускладнень гіпертонічної хвороби пов’язане з температурою атмосферного повітря, віку хворого і часу доби.Запропоновано план роботи середнього медичного персоналу для профілактики гіпертонічних кризів та інших ускладнень гіпертонічної хвороби: 1) формування групи ризику серед пацієнтів зони обслуговування зі значними коливаннями артеріального тиску, особливо в нічний період; 2) розробка журналу щоденної реєстрації загальножиттєвих показників (температура тіла, артеріальний тиск, пульс); 3) навчання та контроль за правильністю реєстрації загальножиттєвих показників; 4) проведення просвітницької роботи щодо факторів ризику та профілактики розвитку гіпертонічної хвороби та її ускладнень