Shielded metal arc welding

About: Shielded metal arc welding is a research topic. Over the lifetime, 4462 publications have been published within this topic receiving 40560 citations. The topic is also known as: manual metal arc welding & flux shielded arc welding.

The effect of welding on the properties of advanced 9–12%Cr steels

Abstract: There are strong environmental and economic pressures to increase the thermal efficiency of fossil fuel fired power stations, and this has led to a steady increase in steam temperatures and pressures resulting in worldwide plans for ultrasupercritical power plants. Basic investigations on the weldability of advanced 9–12%Cr steels which are either currently in use or which are intended to fulfil this requirement were performed on pipes of P91, E911 and a tungsten containing cast steel G-X 12 CrMoWVNbN 10 1 1. Gleeble simulations representing the manual metal arc welding process were applied to produce HAZ simulated microstructures. After different post-weld heat treatments they were tested using hardness tests, metallographic investigations, constant strain rate tests, and creep tests. Particular attention was given to the softening effect in the HAZ and its influence on the creep resistance of the welded material. This decrease, shown by simulated and manufacturing welded samples, seems to be les...

Respiratory Exposure to Toxic Gases and Metal Fumes Produced by Welding Processes and Pulmonary Function Tests

Abstract: Background: Welding is a common industrial process and is harmful to welders' health. Objective: To determine the effect of toxic gases and metal fumes produced during 3 welding processes on welders' incidence of respiratory symptoms and pulmonary function. Methods: This cross-sectional study was conducted in an Iranian shipbuilding industrial factory in 2018. Using the simple census method, 60 welders were selected as the exposed group. 45 staff members of the administrative unit were also recruited to be served as the control group. Welders' demographic data and respiratory complaints were collected employing a questionnaire. Fumes and gases produced were sampled from the welders' respiratory tract and analyzed by standard methods suggested by the National Institute of Occupational Safety and Health (NIOSH). Pulmonary function test was also performed for each participant. Results: The prevalence of respiratory symptoms in all welders was significantly (p<0.05) higher than the control group. The mean FVC, FEV 1 and FEV 1 /FVC measured in welders involved in all 3 processes were significantly lower than those recorded in the control group. The spirometry pattern in welders involved in flux cored arc welding and shielded metal arc welding was obstructive; that in those involved in gas metal arch welding was mixed (obstructive and restrictive pattern). Conclusion: Exposure to welding fumes and gases was associated with pulmonary function deterioration. Welders involved in gas metal arch welding had a higher prevalence of pulmonary disorders compared with those involved in gas metal arch welding and flux cored arc welding.

Hardsurfacing welding wire and process

Abstract: A welding wire comprising a flux core having a core composition alloyed with a combination of alloying elements is described. The alloying elements comprise Cr and N, wherein the flux core comprises between 10% and 50% of the total weight of the weld wire. A metal sheath encapsulates the flux core, wherein the metal sheath comprises between about 90% and 50% of the total weight of the welding wire and wherein the welding wire can be used in a welding process without destabilizing a welding arc. One of the applications of the wire and welding process of the present invention is hard surfacing of the steel mill rolls, which are hollow cylinders usually on continuous casters. As an example, the rolls welded by the wire and method of the present invention can have a diameter of about 12 inches or less. Additionally, a welding apparatus comprising a welding gun with a device for feeding an electrode into the welding gun is described. The corresponding welding process calls for gas shielding of the electrode to reduce spatter and smoke emission while creating a smooth weld bead surface requiring less grinding and finishing. The resulting weld deposit has enhanced resistance to pitting corrosion.