Selected properties of hybrid PTA-MAG welded joints of thermomechanically rolled s700mc steel

Abstract

The aim of this paper is to describe the selected mechanical properties and microstructure of butt welded joints obtained by the hybrid Plasma+MAG method of S700 MC steel (high strength Re=700 MPa). The results of metallographic research of welded joints, microstructure of the weld and heat affected zone, hardness distribution and impact toughness are presented. The tensile test shown that strength of welded joints was slightly reduced and the bending test revealed no crack formation in the weld. The impact toughness of measured welded samples with V-notch in HAZ (heat affected zone) reached high values that are higher comparing to samples with notch placed in the weld area. The investigation results show that the use of hybrid plasma + MAG welding arc does not significantly change the structure and deteriorate properties of welded S700MC thermomechanically treated high strength steel.