METHOD FOR PRODUCING X100 STEEL GRADE ELBOW PIPE AND PIPE FITTINGS

摘要

A method for producing X100 steel grade elbow pipe and pipe fittings comprises: (1) the steel used for X100 elbow pipe and pipe fittings is composed of in mass percentage: C:0.12-0.20%, Mn:1.35-2%, Si:0.3-0.5%, P≤0.010%, S≤0.005%, Al:0.015%-0.05%, Ca:0.002-0.005%, N≤0.007%, or alternatively doped by elements of Nb, Ti, V, Mo, Ni, Cr, Cu and B, and balance Fe; (2) the steel described above is processed into hot rolled steel plate upon smelting, controlled rolling, and cooling in air; and then is processed into longitudinal submerged arc welded steel pipe by shaping and longitudinal submerged arc welding; and is manufactured into elbow pipe by induction heating, bending and heat treatment, or is manufactured into pipe fittings by multiple hot mechanical formation. The elbow pipe or pipe fittings produced by the method has high strength, good low temperature toughness and weldability.