Effect of SMAW Welding Parameters on Mechanical and Structure Properties of Welded Joints of the Armoured Steel 0.32%C, 1%Cr, 1.8%Ni and 0.7% Mo

Document Type : Original Article

Authors

Egyptian Armed Forces, Egypt.

Abstract

This paper introduces the effect of Shielded Metal Arc Welding (SMAW) welding parameters on the mechanical and structure properties of welded joints of the quenched and tempered armoured steel 0.32%C, 1%Cr, 1.8%Ni and 0.7% Mo. In this study, three welding consumables – low-carbon & low-alloy which are both Low Hydrogen Ferritic (LHF) electrodes, and austenitic stainless steel (ASS) electrode - and three heat inputs were used. Furthermore, the effect of preheating of the armoured plates on the mechanical properties of both the welded joint and the heat affected zone was investigated. The use of the lowhydrogen ferritic electrodes provided superior tensile properties while the austenitic electrodes exhibited pronounced toughness. Higher heat input and/or preheating should be performed when using LHF electrodes, however, caution should be given when using lowalloy steel electrodes due to their sensitivity to the applied cooling rate. On the contrary, preheating is less important when using ASS electrodes due to their high resistance to cold cracking. Higher heat input and preheating temperatures increase the softening of the hardened region, adjacent to the fusion zone, which decrease the possibility of Hydrogen induced cracking (HIC).

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