Development of Post-weld Electrodynamic Treatment Using Electric Current Pulses for Control of Stress-Strain States and Improvement of Life of Welded Structures

Abstract

The present work was aimed at the development of a new technological process: a post-weld electrodynamic treatment of welded joints by pulses of a high-density current. Generators of the pulse current and electrode devices, realizing the preset parameters of electrodynamic effects at single- and two-channel schemes, were designed and manufactured. The results of experimental investigations, carried out on specimens of base metal and welded joints, showed that the electrodynamic treatment has a positive effect on the structure of the treated metal and allows the residual stresses in welded joints to decrease gently, increasing their resistance to fatigue and brittle fracture as well as eliminating the distortion deformations in thin-walled elements of structures. The developed technologies and equipment gave an opportunity to perform the electrodynamic treatment of welded joints of hull structures of ships of aluminum alloy AMg6 and repair welds of an intermediate casing of the aircraft engine of heat-resistant magnesium alloy ML10, thus promoting an increase in their service reliability and life.

Detecting development scenarios of dynamic events in electric power networks smart-grid Part1 “Method”

“…6). The task of the SCADa is to provide information on the essence of transient processes in the OCP, on the result of recognising the existing SceN, and SN in the OCP operation, forming recommendations for operating personnel, emergency files for analysing the accident, commands for localizing accidents, blocking personnel wrong actions, diagnosing malfunctions [33,34], [35,36] and monitoring the current the state of the OCP with and without the participation of operating personnel [37,38], [39,40]. It is implemented graphically on the SCADa screen in the form of a widget with filled active places on semantic messages prepared to help operational personnel.…”

Some Physical Processes in the Application of the Electrodynamic Method of Metal Processing

“…Non-contact induction method current input in a limited area of the weld [9,10] is characterized by relative simplicity of use and low energy consumption. A promising way to improve the mechanical and operational characteristics of welded joints is electrodynamic treatment -a new method based on the simultaneous local action of pulsed electrodynamic force and pulsed electric current flowing due to direct contact [11,12]. It is due to the flow of high-density pulsed current that the realization of the electroplastic effect becomes possible [2].…”

“…where i is imaginary unit. The constants 11 A and 12 A in (12) are defined from the initial conditions (9):…”

“…D. Current pulse in the metal plate. For a metal plate with high electrical conductivity  , for example aluminum, and current pulse parameters used in experiments [12], we can assume that the field penetration depth into the plate for the characteristic frequencies of the current pulse significantly exceeds the radius of the dent e   …”

Сучасний Стан І Перспективи Застосування Електромагнітних Полів При Зварюванні Та В Суміжних Процесах І Технологіях

“…Локалізація ІЕС в зоні деформування зменшує фактор розсіювання силових ліній струму, забезпечуючи тим самим досягнення порогової щільності, яка є необхідною умовою реалізації ЕПЕ. Взаємодія складових електродинамічного впливу в період проходження ІЕС через метал визначає ефективність впливу ЕДО на залишкові напруження, еволюцію структури, точність і довговічність зварних конструкцій із легких сплавів [10][11][12].…”