Weld metals with superior low temperature toughness for joining high strength, low alloy steels

摘要

Weld metals suitable for joining high strength, low alloy steels are provided. These weld metals have microstructures of acicular ferrite interspersed in a hard constituent, such as lath martensite, yield strengths of at least about 690 MPa (100 ksi), and DBTTs lower than about -50° C. (-58° F.) as measured by a Charpy energy versus temperature curve. These weld metals include about 0.04 wt % to about 0.08 wt % carbon; about 1.0 wt % to about 2.0 wt % manganese; about 0.2 wt % to about 0.7 wt % silicon; about 0.30 wt % to 0.80 wt % molybdenum; about 2.3 wt % to about 3.5 wt % nickel; about 0.0175 wt % to about 0.0400 wt % oxygen, and at least one additive selected from the group consisting of (i) up to about 0.04 wt % zirconium, and (ii) up to about 0.02 wt % titanium.