Microstructural evolution and chemical corrosion of electron beam wire-feed additively manufactured AISI 304 stainless steel

Using an electron beam wire-feed additive manufacturing three sets of samples were obtained at different heat input levels. The samples contained different amounts of vermicular delta-ferrite that depended on the heat input value used. Chemical corrosion tests were carried out to find out that the corrosion resistance of a sample is determined by the delta-ferrite amount in it. High delta-ferrite content in the sample obtained at medium used heat input value caused enhanced corrosion in the Cr-depleted austenite grains. Otherwise, when using the maximum heat input the additively manufactured sample contained the minimum amount of delta-ferrite and demonstrated the highest corrosion resistance as well as formation of a cubic crystallographic texture. No such texture was found in samples grown at lower heat input values. In addition, no inter-granular corrosion induced open cracks have been observed on all samples after 90 degrees angle flexural test. (C) 2019 Elsevier B.V. All rights reserved.