GAS TUNGSTEN ARC WELDED JOINTS AND METHODS OF PRODUCTION THEREOF

Abstract

The present invention provides, in the form of a welded joint for high-Mn steel to be used in cryogenic environments, a gas tungsten arc welding technology that can achieve further improvement of the weld metal strength and enhanced inhibition of the formation of hot cracks. A gas tungsten arc-welded joint of pieces of a steel material produced using a shielding gas and a filler metal is provided. The steel material is an austenitic steel with a high Mn content. The chemical composition of the welding material includes, in mass %, C: 0.15 to 0.80%, Si: 0.10 to 1.00%, Mn: 17.0 to 30.0%, P: 0.030% or less, S: 0.030% or less, Al: 0.005 to 0.100%, Cr: 0.4 to 5.5%, Mo: 0.01 to 3.50%, Ni: 0.01 to 10.00%, and N: 0.0400 to 0.4000%, with the remainder consisting of Fe and unavoidable impurities.Further provided is a method of producing a welded joint wherein a nitrogen gas is contained in a shielding gas, or a content of N in a filler metal is increased, to form the weld metal described above.