Production manner null of the welding structure which is superior in resistance hydrogen sulfide stress corrosion crack property and low temperature

摘要

PURPOSE: To manufacture a welded structure such as a pressure vessel of large capacity where the low temperature toughness is excellent even with extremely large plate thickness, and the sensitivity to the stress corrosion crack is low by welding the high tensile steel of the prescribed extremely large thickness and low weld hardening property using the prescribed welding electrode, and executing the prescribed heat treatment. ;CONSTITUTION: The steel having the composition consisting of, by weight, ≤0.02-0.15% C, 0.05-0.6% Si, 0.5-2.0% Mn, ≤0.3% Ni, ≤0.035% P, ≤0.005% S, ≤0.05% Cr, ≤0.05% V, ≤0.5% Cu, and the balance Fe is rolled, and then quenched in the temperature range of A_c3 transformation temperature +30 to A_c3 transformation temperature +200°C, and then, annealed in the temperature range of A_c1 transformation temperature -40 to A_c1 transformation temperature -200°C. The steel is welded by the coated electrode having the composition consisting of, by weight, 0.02-0.13% C, 0.05-0.6% Si, 0.5-2.0% Mn, ≤0.35% P, ≤0.01% S, 0.001-0.05% Ti, 0.001-0.08% B, ≤0.1% Ni and the balance Fe, annealed, and the hardness is ≤200 in terms of the Brinell hardness Hb.;COPYRIGHT: (C)1995,JPO