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.

Method for welding iron steel and nonferrous alloy

Abstract: In welding iron, steel, and nonferrous alloys, the wire feed is changed periodically and in synchronism with periodic changes of the electric welding current to establish a previously defined relation between the welding current value and the arc length. The welding current is varied between one producing a spray transfer arc and a current just maintaining the arc.

Profiling stainless steel welding processes to reduce fume emissions, hexavalent chromium emissions and operating costs in the workplace

Abstract: Nine gas metal arc welding (GMAW) processes for stainless steel were assessed for fume generation rates, fume generation rates per g of electrode consumed, and emission rates for hexavalent chromium (Cr6+). Elemental manganese, nickel, chromium, iron emissions per unit length of weld, and labor plus consumables costs were similarly measured. Flux-cored arc welding and shielded metal arc (SMAW) processes were also studied. The objective was to identify the best welding processes for reducing workplace exposures, and estimate costs for all processes. Using a conical chamber, fumes were collected, weighed, recovered, and analyzed by inductively coupled atomic emission spectroscopy for metals, and by ion chromatography for Cr6+. GMAW processes used were Surface Tension Transfer, Regulated Metal Deposition, Cold Metal Transfer, short-circuit, axial spray, and pulsed spray modes. Flux-cored welding used gas shielding; SMAW used E308 rods. Costs were estimated as dollars per m length of a ¼ in (6.3 mm) t...

Weldability of Ferritic Ductile Cast Iron Using Full Factorial Design of Experiment

Abstract: The weldability of a ferritic ductile cast iron was investigated as a function of diferent consumables and welding conditions. A 23 full factorial experimental design was used to analyze the effect of factors and their interactions on ultimate tensile strength of weldments. The shielded metal arc welding (SMAW) process was used with two types of consumables (E7018 and ENi-CI) under eight diferent conditions using asGcast samples. The microstructural evolution and fracture mechanisms were investigated by optical microscopy and scanning electron microscopy (SEM), respectively. The hardness, tensile and impact tests were also performed to determine the weld quality Based on experiment design, preheat, consumable, cooling condition, preheat-cooling and preheat-consumable interactions were significant factors. Preheat is the most efective factor and in the case of E7018, preheat and cooling conditions were the most sensible factors. It was found that butering was the most appropriate welding method for ferritic ductile cast iron.

Arc welding method and arc welding apparatus

Abstract: This invention provides arc welding methods and arc welding apparatus which weld materials by giving a plastic deformation of definite curvature to wire itself in a process before supplying the wire to a welding nozzle, restoring the wire delivered from the welding nozzle to the plastic deformation of definite curvature, delivering rotatively the end of the wire in a definite period from a delivery hole of the welding nozzle in butt welding of thick board, especially narrow gap welding.

High variability in toxicity of welding fume nanoparticles from stainless steel in lung cells and reporter cell lines: the role of particle reactivity and solubility

Abstract: Millions of people in the world perform welding as their primary occupation resulting in exposure to metal-containing nanoparticles in the fumes generated. Even though health effects including airway diseases are well-known, there is currently a lack of studies investigating how different welding set-ups and conditions affect the toxicity of generated nanoparticles of the welding fume. The aim of this study was to investigate the toxicity of nine types of welding fume particles generated via active gas shielded metal arc welding (GMAW) of chromium-containing stainless steel under different conditions and, furthermore, to correlate the toxicity to the particle characteristics. Toxicological endpoints investigated were generation of reactive oxygen species (ROS), cytotoxicity, genotoxicity and activation of ToxTracker reporter cell lines. The results clearly underline that the choice of filler material has a large influence on the toxic potential. Fume particles generated by welding with the tested flux-cored wire (FCW) were found to be more cytotoxic compared to particles generated by welding with solid wire or metal-cored wire (MCW). FCW fume particles were also the most potent in causing ROS and DNA damage and they furthermore activated reporters related to DNA double- strand breaks and p53 signaling. Interestingly, the FCW fume particles were the most soluble in PBS, releasing more chromium in the hexavalent form and manganese compared to the other fumes. These results emphasize the importance of solubility of different metal constituents of the fume particles, rather than the total metal content, for their acute toxic potential.