Weldments Subjected to Quasi-static Eccentric Loading and "Out of Plane" Structural Impact Loading

Abstract

This paper shows results of an investigation on the behavior of assemblies produced with welded fillet joints subjected to eccentric, quasi-static and “out-of-plane” structural impact loads. Therefore, weldments were manufactured, with one of the elements in “balance”, using ASTM A-36 and ASTM A-572 grade 50 structural steels, joined by the process of gas metal arc welding (GMAW or MAG). For the purpose of comparison, all weld beads were made with parameters kept constant and classes AWS ER70S-6 and AWS ER120S-G electrodes. Among the main results, it was observed that in tests with quasi-static loading, for both base metals, the parallel weld beads welded with AWS ER120S-G preheated to 150 °C withstood greater loads for shorter times, and the transverse weld beads withstand smaller loads for longer periods of time. Related to structural impact tests of ASTM A572 grade 50 base metal weldments, the parallel weld beads welded with electrode AWS ER70S-6, preheated to 150 °C, withstood near to 50% of the designed load. Fracture surfaces produced by structural impact loading of the weld beads with the AWS ER120S-G electrode were analyzed by scanning electron microscopy. Parallel weld beads produced fractures witch ductile characteristics, and perpendicular weld beads produced ductile fractures with cleavage planes.

Key-words:
Welding; Structural impact; Fillet joints; Welded assemblies; Quasi-static eccentric loading and "Out of Plane" structural impact