Kazuki Fujiwara

Proposal of welding consumable of triplex stainless steel for ultrahigh strength steel

Abstract In order to develop a new welding consumable for the ultrahigh strength HT980 steel, the microstructural characteristics, tensile properties, low temperature toughness and weld cracking susceptibility were evaluated for triplex stainless steel weld metals. Steels of 13Cr–0·5Mo–Ni with varying contents of Ni and C were investigated. The amount of retained austenite increased with increasing Ni and C contents. The tensile strengths of the weld metals decreased while their impact absorbed energies increased with increasing amount of retained austenite. Hot cracking susceptibility of the weld metals minimised in that metal containing 40–50% δ-ferrite at the completion of solidification. The triplex stainless steel weld metals, except for those containing lower amounts of retained austenite, were negligibly susceptible to cold cracking. It may be possible to design a preheat free welding consumable from a triplex stainless steel in the compositional range containing 20–40% of retained austenite.