Determining the effects of alloy composition, forging technique, and flux on the strength of forge welds

Abstract

Welding is an essential manufacturing process in industries that require the joining of metal components such as the automotive and aerospace industries. While specialized techniques have developed for many of these industries, the process of welding remains fundamentality the same, and the effectiveness of these processes to securely join metal is always characterized by the material properties of the metal after welding. The tensile test performance of forge welds when made with different iron alloys, forge welding techniques, and fluxes was measured. The alloys used were 1018 steel, A36 steel and wrought iron. The forge welding techniques were the hydraulic press, the power hammer, and hand hammer. The fluxes were borax, fine silica sand, anti-borax, and no flux. Control tensile samples (un-welded) of each alloy, as received, were tested along with annealed samples. All testing was performed with an Instron 5984 Universal Testing Machine with 150kN capacity. The results of the welded alloy tests showed that welded 1018 and A36 steel both had considerably lower strength than their control annealed counterparts, whereas welded wrought iron remained just as strong. The results of the forge welding techniques test showed consistent welded A36 steel strengths across techniques used which may suggest that the effectiveness of particular techniques may be more dependent on experience and practice. The flux results show that silica sand and anti-borax work just as well as, if not better than, borax. Using no flux resulted in failed welding, revealing that achieving successful welds without flux requires more welding experience or a different method than the one performed by the welder of the samples for the present experiment. The results of the control alloys showed that 1018 and A36 steel both had considerably lower strength than their annealed counterparts, whereas wrought iron remained just as strong.