Welded ferritic stainless steel articles - stabilised against stress and crevice corrosion with niobium and/or titanium (NL 31.10.77)

摘要

Welded article of ferritic stainless steel contains 0.04% C and 0.04% N, provided (C + N) % is 0.006-0.07%; 23-38% Cr, 2-4.75 % Ni, 0.75-3.5% Mo, Nb and/or Ti in specified quantities, bal. Fe and unavoidable impurities. Nb quantity is 0.05-0.7% and Ti is absent when Nb content is equal to 8x (C + N) and (C + N) % 0.04%. Ti quantity is 0.12-0.7% and NB is absent, when Ti content is at leaset 6x (C + N) and (C + N) % =0.02%. Quantitie of Nb and Ti are 0.3% each when lowest quantity is indicated by equation % Ti/6 + % Nb/8 = % (C + N) and (C + N) % is 0.02-0.07%. Welded parts may be used in media contg. salts and chemicals, e.g. as pipe conduits or heat-exchangers, in petrochemical and chemical industry, desalination technology, fibre- and paper-prodn. and in electrical power generation. Welded parts resits crevice corrosion in sea water and other ambient media at about 40 degrees c.