Research On Microstructure And Mechanical Properties Of Gmaw Welded Joint In Hyperbaric Environment

In recent years,the number of underwater engineering has increased rapidly with the continuous development of marine resources.The connections and restoration of underwater structures depend on the advanced underwater welding technology.The welding quality determines the stability and service life of the whole project.So it is of great significance to conduct researches on the underwater welding quality.At present,the Underwater Hyperbaric Dry Welding has become a hot research topic due to its high welding quality.GMAW is easy to be realized in the automation and intelligent welding.The study on the microstructure and mechanical properties of hyperbaric GMAW welded joint will provide the basic data for the underwater hyperbaric dry automatic welding.The welding process is unstable when it is carried out in underwater hyperbaric environment,so the welding quality will be inevitably affected.However,it is not clear about the degree of the specific effects and its results.Thus,it is urgent to study the quality of hyperbaric dry GMAW welding.According to the requirements of the welding plate,the hyperbaric welding platform was reconstructed,and the welding tests were made under different environmental pressures with Q235 C as the base material.In the study of the microstructure and mechanical property of the welded joint,the environmental pressure,welding current,welding voltage,welding torch swing and the protective gas flow rate will be considered.The welding stability will be analyzed by welding analyzer.The microstructure of welded joint will be observed,and the mechanical property test will be carried out to determine the influence of environmental pressure on the welding quality.Based on the research on the microstructure and performance,the welding parameters of 0.1MPa~1.3MPa will be optimized.Through a series of hyperbaric welding experiments,the microstructures and mechanical properties of GMAW welding joint organization in high pressure environment will be analyzed,and the reasonable welding parameters under high pressure will be determined,which provided a theoretical basis for better high welding quality.