Influence of Manganese and Coating Basicity on the Microstructure and Mechanical Properties of Vertical-Up MMA Welds in 38mm Thick C-Mn-Nb Steel Plate - Final Report

TWI Industrial Member Report Summary 309/1986

By D J Abson

Background

A project has been undertaken to examine the influence of varying manganese and silicon contents and coating basicity on the microstructure and toughness of manual metal arc (MMA) weld metal (WM) for C-Mn type steels. In the present work, vertical-up MMA deposits have been produced in 38mm thick C-Mn-Nb steel plate using experimental basic coated electrodes at an arc energy of ~1.3kJ/mm. Two levels of deposit manganese, ~1.35 and ~1.75% were employed, and a low level of silicon ( ~0.3%) for comparison with a previous phase in which deposit silicon was ~0.7%. Coating basicity index (BI) was varied at the higher manganese level.