Influence of welding technology to mechanical properties of welding joints at high strength low alloy steels

Abstract

In this paper the analysis of welding technology to stress-strain state at zones of welded joints at high strength low alloy steel S690QL is presented. Experimental testing was done at specimens with V-groove butt joints that are done by MMA or MIG for root pass and MAG for other passes with related welding consumables. Basic mechanical properties and answer to load of specimens are determined in order to analyses the effect of welding technology to stress-state at zones of welded joints. On the basis of the experimental results it is concluded that welding parameters influent to mechanical properties of joints at high strength low alloy steel S690QL. Those mechanical properties are, primary, related to microstructural transformations caused by thermic cycles due to welding. On the basis of the experimentally obtained results it is concluded that welds with root pass by MIG and other passes by MAG provide better mechanical properties. The general conclusion is that welding parameters at high strength low alloy steels must be selected and controlled with great care in order to obtain welding joints with adequate mechanical properties and, by that, provide beneficial applications of those materials.