在二氧化碳保护气中用CB-10ΓC焊丝半自动焊接Cт3C,Cт4C和CXЛ—1号钢结构的经验表明:虽然焊接过程生产率高,成本低,强度极限和延伸率满意(σ_B=54公斤/公厘~2,δ=26～28％),但是冲击值比较低(a_k<10公斤-公尺/公尺~2),焊缝金属有纵向裂缝,金属飞溅多,焊缝外形质量差。实验查明,焊缝冲击值低和形成裂缝的原因是由于:(1)还原性元素锰和硅被大量 The experience of semi-automatic welding of Cт3C, Cт4C and CXL-1 steel structures with CB-10ΓC wire in carbon dioxide shielding gas shows that although the welding process has high productivity, low cost, good strength and satisfactory elongation (σ_B = 54 kg / 2, δ = 26-28%), but the impact value is relatively low (a_k <10 kg-m / m ~ 2). The weld metal has longitudinal cracks, metal splashes and poor weld profile. Experiments show that the weld impact value is low and the reasons for the formation of cracks due to: (1) the reduction of elements manganese and silicon by a large number