The Influence of Titanium Additions and Interpass Temperature on the Microstructures and Mechanical Properties of High Strength SMA Weld Metals

Abstract

The influence of titanium additions and interpass temperature on the microstructures and properties in low carbon-1.5Mn-3Ni-0.5Mo multiple pass steel weld metals produced using the shielded metal arc welding (SMAW) process was studied. Robust weld metals with high strength (> 690 MPa) and toughness (100 J at −70°C) were produced when titanium concentrations of 180 to 400 ppm were added to a base chemical composition of low carbon-1.5Mn-3Ni-0.5Mo steels. High toughness was measured in weld metals containing either 30 to 90 ppm titanium or 180 to 400 ppm titanium while deteriorated weld metal toughness was observed when weld metal titanium concentrations were less than 10 ppm, 90 to 180 ppm, or more than 400 ppm. The microstructures of these low carbon weld metals were complex. The difference between the classification systems used for weld metals and base metals was addressed. © 1995, The Iron and Steel Institute of Japan. All rights reserved.