Comparison of the mechanical properties and microstructural evolution in the HAZ of HSLA DOMEX 700MC welded by gas metal arc welding and electron beam welding

Abstract

High strength low alloyed steels are nowadays an important group of engineering materials, with numerous industrial applications. Properly chosen chemical composition together with the thermomechanical processing allow to reach high mechanical properties, while the carbon content is maintained low. Resulting microstructure is therefore sensitive to the amount of the heat introduced to the metal during welding. During welding procedure, softening phenomenon can occur in the heat affected zones and it could lead to the degradation of the mechanical properties of the final joint. Nowadays, welding technologies based on the high energy electron beam are able to produce weld joints with very narrow heat affected zone. In this study, authors compare mechanical properties and the microstructural evolution in the heat affected zone of the GMAW and EB welded joint of the DOMEX 700MC HSLA steel. The carried out experiments showed that both evaluated technologies are able to produce joints with appropriate mechanical properties. Welded joints made by the EBW technique showed slightly better mechanical properties of the whole joint, as a result of the narrower HAZ.

Effect of the t8/5 Cooling Time on the Properties of S960MC Steel in the HAZ of Welded Joints Evaluated by Thermal Physical Simulation

“…Due to this, they are suitable for welding technologies with a concentrated heat source such as laser welding or electron beam welding. These phenomena are described in research papers by Guo et al [11,12] and Kopas et al [13]. Combining multiple techniques into one-the use of so-called hybrid technologies-is also one of the ways to achieve HSLA welded joints with satisfactory properties.…”

Comparative Analysis of the Mechanical Exploitation Properties of the Steel Sheet Welded Joint of New and Old Materials

“…This means that the correct choice of preheating temperature is a very important step that ensures a more stable structure. The main reason for preheating is the increase of the general quality of welded joints, which is achieved through the following: reducing the cooling rate of the welded joint, reducing the residual stresses in the welded joint, reducing the hardness in the HAZ, increasing the impact toughness in the welded joint, and reducing the tendency to the formation of cracks [8]. A schematic representation of the preparation of the welded joint shape is given in Figure 2, whereas the welding sequence is given in Figure 3.…”

Effect of Welding Methods on Mechanical Properties of Domex 700MC Steel

“…High mechanical properties and fine-grained microstructure of high-strength low-alloyed (HSLA) steels resulting from low carbon content and microalloying up to 0.15 wt.% by niobium, titanium, and vanadium are achieved by thermomechanical controlled treatment [1,2]. Domex 700MC steel is a high-strength, low-alloy steel that is widely used in bridge and crane construction.…”