| 摘要 |
High-strength welded steel structures having excellent SSC and corrosion resistances in a wet carbon dioxide environment having a low H2 S concentration. (1) A structure having a Vickers hardness of at most 350 and a joint tensil strength of at least 620 Mpa and composed of a base metal comprising a martensitic stainless steel with a martensitic or tempered martensitic structure containing 0.001 to 0.05 % C and 9 to 14 % Cr and a weld metal comprising an austenitic-ferritic stainless steel having a duplex structure composed of austenite and 35 to 75 % by volume of ferrite and containing 22 to 27 % Cr, 7 to 11 % Ni and 1.5 to 5 % Mo, and at most 0.03 % C as an impurity. (2) Another structure according to the above item (1), wherein the base metal comprises the elements described in the above item (1) and further comprises Mn, Ni, sol. Al, Mo, Cu, Ti or the like, and Fe and the weld metal comprises the elements described in the above item (1) and further comprises sol. Al, N, Cu, W or the like, and Fe. (3) Still another structure according to the above item (2), wherein the content of C, Mn, Cr or the like of the base metal is further limited to a narrower range, and so is the content of Mn, Cu, W or the like. <IMAGE> |
