A two-dimensional thermal elasto-plastic numerical model is developed by finite element method to analyze and compare the mechanical driving factor for heat affected zone (HAZ) liquation cracking during laser welding and hybrid laser-arc welding techniques. Calculations of transient temperatures and cooling rates are used in conjunction with solidification theory to analyze weld pool characteri...

Submerged arc welding is used widely in oil and gas industry construction for storage tanks, pressure vessels, shipbuilding and etc. One of the processes of submerged arc welding is back gouging operations. This paper presents a way to remove the back gouging operation from the submerged arc welding process. For this purpose, effects of submerged arc welding parameters onA516-70steel sample wer...

A compound external magnetic field (EMF) can be used to prevent weld bead defects by controlling the metal transfer and arc behaviors during high-speed gas welding. unified model containing filler metal, arc, pool, EMF was established study effect of on welding process. The heat mass among pool under action numerically analyzed. simulation results showed that high-temperature region in molten r...

Ultraviolet radiation (UVR) emitted during arc welding frequently causes keratoconjunctivitis and erythema. The extent of the hazard of UVR varies depending on the welding method and conditions. Therefore, it is important to identify the levels of UVR that are present under various conditions. In this study, we experimentally evaluated the hazard of UVR emitted in gas tungsten arc welding (GTAW...

Metal arc welding ranges from primitive (manual) to increasingly complex automated welding processes. Welding occupies 1% of the labour force in some industrialised countries and increasing knowledge of health risks, necessitating improved assessment strategies and controls have been identified by the International Institute of Welding (IIW), ILO, WHO and other authoritative bodies. Challenges ...

Background: Hazardous chemical agents in the welding operation are a mixture of metal fumes and toxic gases, the inhalation of which causes adverse health effects among welders. The emission of gases in the workplace is a logical cause for concern regarding the potential development of respiratory disease. The aim of the present study was to determine the concentration values of gases discharge...

Abstract: By using the Lyapunov second method, the robust control and robust optimal control for the gas tungsten arc welding dynamic process whose underlying continuous-time systems are subjected to structured uncertainties are discussed in time-domain. As results, some sufficient conditions of robust stability and the corresponding robust control laws are derived. All these results are design...

INTRODUCTION: Electric arc welding and oxy-fuel gas welding are the commonest welding technologies used in small scale industries in Nigeria. Electric arc welders are exposed to serious health hazards like exposure to welding smoke. Health effects of such exposure include metal fume fever, and increased risk of chronic diseases and cancers. Exposure to welding smoke can be minimized by use of P...