TWO-PHASE STAINLESS STEEL FOR UREA PRODUCTION PLANT, WELDING MATERIAL AND UREA PRODUCTION PLANT

摘要

PROBLEM TO BE SOLVED: To provide a two-phase stainless steel which has excellent corrosion resistance and is suitable for a material of various equipments in a urea production plant; a welding material; and the urea production plant.;SOLUTION: The two-phase stainless steel for the urea production plant comprises, by mass%, 0.03% or less C, 0.5% or less Si, 2.0% or less Mn, 0.04% or less P, 0.003% or less S, 26.0% to 28.0% Cr, 6.0-12.0% Ni, 0.2-1.7% Mo, 2.0% to 3.0% W, 0.07% to 0.30% N, while satisfying the following expression (1): Cr²×(N-0.005Ni)-170≤0, wherein Cr, N and Ni represent respective contents (by mass%), and the balance Fe with impurities which include 0.3% or less Cu. The welding material is made from the stainless steel. The steel or the welding material may further include one or more elements selected from among Ca, Ce and B.;COPYRIGHT: (C)2007,JPO&INPIT