Is superior in resistance sulfide stress corrosion crack Characteristic and low temperature Characteristic the welding structural steel

摘要

PURPOSE:To provide a steel for thick welding structures most suitable for structures used in an environment contg. H2S and excellent in SSCC resistance, low temp. toughness and weldability. CONSTITUTION:This steel contains, by weight, =0.2% C, =40.2% Si, 0.4 to 1% Mn, 0.5 to 2.5% Ni, 2 to 3% Cr, 0.5 to 1.5% Mo and 0.01 to 0.06%. Al, and the balance Fe with inevitable impurities. Excellent hardenability is secured, sufficient hardening is executed to the central part even if it is a thick material and desired strength can be obtd. as well as its weldability, low temp. toughness and SSCC resistance are furthermore excellent. It is applicable to a large-sized structural material.