900 MPa级超高强气保焊丝的研制

Development of 900 MPa grade high strength GMAW welding wire

确定了焊丝合适的化学成分,主要合金元素为Ni、Mo、Cr,碳当量CE=0.70％～0.90％.试制了900 MPa级气体保护焊丝,其冶炼及拉拔工艺可行.以（ψ）（Ar）80％＋（ψ）（CO2）20％作保护气体,焊接熔敷金属抗拉强度典型值960 MPa,-20℃冲击韧性67J,马氏体＋贝氏体组织.降低C、Cr及Mo含量、增加Ni含量,焊缝韧性增加.焊丝适用于900 MPa及以上级别超高强钢的焊接.

The chemical composition of the wire was designed mainly with alloying elements of Ni, Mo,and Cr, and carbon equivelent CE 0.70 -0.90%. The 900MPa grade high strength GMAW （ Gas Metal Arc Welding） wehting wire was developed, and its steel making and drawing were practicable. Using 80% Ar plus 20% CO2 as shielding gas, the typical welded deposit metal has tensible strength of 960 M Pa, Charpy impact energy of 67 J at -20 ℃,and microstructure of martensite plus bainite. Toughness increse with the decrease of C,Cr and Mo and the increase of Ni. The wire is suitable for the welding of super - high steels of 900 MPa grade or above.