Ferritic austenitic article resisting intercrystalline corrosion - contg. unstabilised alloy welded with ferritic austenitic alloy of different compsn.

摘要

Welded ferritic-austenitic articles are produced by welding an unstabilised alloy (I) consisting of 0.002-0.03% C, 18-26% Cr, 2-8% Ni, 1.6-5% Mo, 0.06-0.2% N, 0.8% Si, 2% Mn, 0.5% V, bal. Fe and standard melt-conditioned impurities, with a ferritic-austenitic additional material, (II) different from base metal, and contg. =0.08% C, 20-26% Cr, 3-12 (8.5-12)% Ni, 1.6-5 (2.2-3.5)% Mo, 0.2-0.8% Si, 0.2-2% Mn, (6-20x%C) % Nb, =0.12% N, balance Fe and standard melt-conditioned impurities. Min. C content of (II) is esp. 0.002 (0.015)% C. Cr content of (II) is esp. 23.5%. Nb may be replaced, in part or entirely, by double amount of Ta. (II) pref. contains also 0.05-0.5% V. (II) is used esp. as a sheathed manual electrode. Welded articles resist intercrystalline corrosion without heat-treatment. Welding can take place without a protective gas, e.g. by electrode manual welding and/or by submerged arc welding. The welded articles may be used up to -60 degrees C.