The invention provides a
coal mine hydraulic support gas shield
welding wire with the strength higher than 900 MPa and a preparation method of the
coal mine hydraulic support gas shield
welding wire. The gas shield
welding wire comprises, by
mass, 0.03%-0.06% of C, 0.51%-0.70% of Si, 1.35%-1.64% of Mn, smaller than or equal to 0.010% of P, smaller than or equal to 0.005% of S, 0.20%-0.38% of Cr, 2.35%-2.65% of Ni, 0%-0.09% of Cu, 0.45%-0.70% of Mo, 0.015%-0.030% of Ti, 0.025%-0.035% of Nb, 0.002%-0.006% of Ce, 0.0005%-0.0012% of B, smaller than or equal to 0.004% of O, smaller than or equal to 0.006% of N and the balance Fe and The invention has the following beneficial effects: (1) through reasonable design of chemical components, the yield strength of
weld metal is greater than or equal to 820 MPa, the tensile strength is greater than or equal to 900 MPa, the
ductility is greater than or equal to 21%, and the low-temperature
impact toughness at-40 DEG C is greater than or equal to 75 J; (2) inclusions in a weld joint are dispersed and refined after the welding wire is welded, refined
acicular ferrite instead of
bainite and
martensite is taken as a main structure, and the strength and
toughness of the weld joint are excellent; and (3) the composition proportion of the welding wire is optimized, a stable welding wire preparation process is developed according to the components, and the comprehensive performance of the high-strength
coal mine hydraulic support welding seam is considered.