TWI Industrial Member Report Summary 344/1987
By D J Abson
A project has been initiated to examine the factors influencing microstructure and toughness of weld metal for C-Mn and microalloyed steels deposited using semi-automatic continuous wire processes. In the first stage of this work, vertical-up butt welds have been produced in 30mm thick BS 4360 Grade 50E steel plate with C-Mn-Ni (~l%Ni) wires. The welds were made with various types of 1.2mm diameter electrode wire, namely rutile and basic tubular wires and metal-cored and solid wires, using Ar-20%C02 shielding and Synergic pulsed power sources, where appropriate. A 2mm self-shielded flux-cored wire was also employed. Tensile properties and Charpy transition curves were determined for root and fill regions, and crack tip opening displacement (CTOD) (on square section specimens) was determined at selected temperatures within the overall range of -50 to +10°C. The findings were related to chemical composition and microstructure.