نتایج جستجو برای: keywords arc welding

تعداد نتایج: 2020129  

2008
K. G. DAVIES U. ASANA C. O. NKU E. E. OSIM

It was generally observed that welders in Calabar, Nigeria did not always wear their protective goggles during welding. Since chronic exposure to welding light can impair vision this study was done to assess the effect of exposure to welding light on ocular function of welders in Calabar, Nigeria. There were 195 subjects comprising 110 welders (test) and 85 control subjects. Both groups were al...

2016
Hitoshi Nakashima Akihiro Utsunomiya Jyunya Takahashi Nobuyuki Fujii Tsutomu Okuno

OBJECTIVES Ultraviolet radiation (UVR) emitted during arc welding frequently causes keratoconjunctivitis and erythema in the workplace. The degree of hazard from UVR exposure depends on the welding method and conditions. Therefore, it is important to identify the UVR levels present under various conditions. METHODS We experimentally evaluated the UVR levels emitted in gas metal arc welding (G...

2016
Mohd Hassan Sanjay Kumar Jha Vijay Pandey

Submerged Arc welding process is automated and semiautomated high deposition down hand welding process not vertical or over welding process, The fundamental difference of this welding process is that the Arc is not visible it is submerged into the flux. Weldment is fully submerged the heat loss is minimum and the thermal efficiency is very high up to 80-90%. A constant power sources and control...

2007
J. Hu H. L. Tsai

A unified comprehensive model was developed to simulate the transport phenomena occurring during the gas metal arc welding process. An interactive coupling between arc plasma; melting of the electrode; droplet formation, detachment, transfer, and impingement onto the workpiece; and weld pool dynamics all were considered. Based on the unified model, a thorough investigation of the plasma arc cha...

2013
T. W. EAGAR

Welding fume contains elements that, in their pure forms, can be hazardous to worker health if inhaled or ingested. Therefore, the chemical composition of welding fume must be examined when considering fume toxicity. Various chemical analysis techniques are presented and their applicability to airborne particles is described. Knowledge of particle size is important because a given characterizat...

Journal: :Occupational and environmental medicine 2005
N Håkansson C Stenlund P Gustavsson C Johansen B Floderus

BACKGROUND Mechanisms for potential effects of extremely low frequency (ELF) magnetic fields on carcinogenesis have not been identified. A potential pathway could be an interaction with the endocrine system. AIMS To analyse occupational exposure to ELF magnetic fields from welding, and tumours of the endocrine glands. METHODS This case-control study was based on a cohort with an increased p...

2001
Y M Zhang Y Ma

Keyhole arc welding (KAW), including the keyhole double-sided arc welding process being developed at the University of Kentucky and keyhole plasma arc welding, can achieve much deeper narrower penetration than all other arc welding processes. If it could be controlled such that the heat input and weld pool are minimized while at the same time the desired full penetration is guaranteed, it could...

2014
J. Dutta

In this research article a comprehensive investigation has been carried out to determine the effect of thermal cycle on temperature dependent process parameters developed during gas tungsten arc (GTA) welding of high carbon (AISI 1090) steel butt joints. An experiment based thermal analysis has been performed to obtain the thermal history. We have focused on different thermophysical properties ...

1999
B Zheng

This paper analyses the arc interference in an a.c. combined (both the pilot arc and the plasma arc exist in the welding process) plasma arc welding of aluminium alloys. This phenomenon results in an unstable welding process and weld formation. To maintain the pilot arc during the period when the electrode is positive, a cathode region must be formed in front of the tungsten electrode tip. Howe...

2017
Mingxuan Yang Ling Li

Arc plasma possesses a constriction phenomenon with a pulsed current. The constriction is created by the Lorentz force, the radial electromagnetic force during arc welding, which determines the energy distribution of the arc plasma. Welding experiments were carried out with ultra-high-frequency pulsed arc welding (UHFP-AW). Ultra-high-speed camera observations were produced for arc surveillance...

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