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.

A Comparative Study on Direct and Pulsed Current Gas Tungsten Arc Welding of Alloy 617

Abstract: the aim of this article is to evaluate the mechanical and microstructure properties of Inconel 617 weldments produced by direct current electrode negative (DCEN) gas tungsten arc welding (GTAW) and pulse current GTAW. In this regard, the micro structural examinations, impact test and hardness test were performed. The results indicated that the joints produced by direct mode GTAW exhibit poor mechanical properties due to presence of coarse grains and dendrites. Grain refining in pulse current GTAW is reason of higher toughness and impact energy than DCEN GTAW. Further investigations showed that the epitaxial growth is existed in both modes that can strongly affect the mechanical behavior of the joints in heat affected zone (HAZ).

Weldability of aluminium-lithium alloy 2090 using laser welding

Abstract: Lithium-containing aluminium alloys are of considerable current interest in the aerospace and aircraft industries because lithium additions to aluminium improve the modulus and decrease the density compared to conventional aluminium alloys. Many such alloys are under development for aircraft applications, which usually involves mechanical fastening. While aluminium-lithium alloys are fusion weldable with gas metal arc, gas tungsten arc and electron beam processes, they suffer from problems of weld porosity, heat-tearing cracking, poor penetration and low joint efficiency. In this paper, the weldability of aluminium-lithium alloys is briefly reviewed. The weldability of commercial aluminium-lithium alloy 2090 in the peak-aged condition was studied using laser welding. The quality of the welds was evaluated through mechanical tests (hardness and tensile tests) and microscopical observations. Mechanical property data and microscopical observations of the welds on prior surface-prepared (milled) material revealed a low degree of the weld surface degradation and an absence of porosity. This coupled with the attractive joint efficiencies suggest the superiority of the laser welding to conventional arc welding of this alloy. The performance of laser-welded butt joints is rationalized.

Microstructure of the Fe-based hardfacing layers reinforced by TiC-VC-Mo2C particles

Abstract: In this study, the hardfacing alloys with different measures of ferrotitanium (Fe–Ti), ferrovanadium (Fe–V), ferromolybdenum (Fe–Mo) and graphite were deposited on AISI 1020 steel substrates by shielded manual arc welding (SMAW). Fe-based hardfacing layers reinforced by carbide particles were produced. The thermodynamic analysis for carbide and effect of the carbide forming elements on the properties of hardfacing layers were also discussed. The experimental results showed that TiC-VC-Mo 2 C carbides could be synthesized by metallurgic reaction during SMAW process. Carbides with particle sizes in the range 1–3 μm are uniformly dispersed in the matrix. The hardfacing layer with good cracking resistance and high hardness could be obtained when the amounts of graphite, Fe–Ti, Fe–V and Fe–Mo were controlled within a range of 8–10%, 12–15%, 10–12% and 2–4%, respectively.