研制了一种低合金钢用埋弧焊焊丝，以Q345B钢板作为母材进行焊接。对熔敷金属的化学成分、显微组织和力学性能进行分析。结果表明：焊丝及熔敷金属的化学成分符合设计要求，熔敷金属显微组织为无碳化物贝氏体，熔敷金属的屈服强度为560 MPa~590 MPa，抗拉强度为640 MPa~675 MPa，断后伸长率不小于25.0%，断面收缩率不小于73%，维氏硬度为225~230 HV，冲击转变温度为-55~-50℃，熔敷金属的扩散氢含量小于4.0 mL/100 g。

A submerged arc welding wire for low alloy steel was developed, and Q345B steel plate was used as the base metal for welding. The chemical composition, microstructure and mechanical properties of the welding wire and deposited metal were analyzed. The results show that the chemical composition of the welding wire and deposited metal met the design requirements, the microstructure of the deposited metal was carbide-free bainite, the yield strength of the deposited metal was 560 MPa~590 MPa, the tensile strength was 640 MPa~675 MPa, the elongation after fracture was not less than 25.0%, the section shrinkage was not less than 73%, the Vickers hardness was 225~230 HV, the impact transition temperature was -55~-50℃, and the diffusion hydrogen content of the deposited metal was less than 4.0 mL/100 g.