High-strength weather-resistant bridge steel and preparation process thereof

The invention discloses high-strength weather-resistant bridge steel and a preparation process thereof, and the high-strength weather-resistant bridge steel comprises 0.07 to 0.08 wt% of carbon, 0.24 to 0.26 wt% of silicon, 1.0 to 1.2 wt% of manganese, 0.0011 to 0.0012 wt% of calcium, 0.04 to 0.05 wt% of niobium, 0.012 to 0.016 wt% of titanium, 0.33 to 0.38 wt% of nickel, 0.5 to 0.6 wt% of chromium, 0.4 to 0.5 wt% of copper, 0.0006 to 0.0011 wt% of rare earth element, less than or equal to 0.012 wt% of phosphorus and the balance of iron. The content of sulfur is less than or equal to 0.002 wt%. According to the invention, the problem that large-particle rare earth inclusions block a pouring nozzle or remain in steel to deteriorate the impact property due to excessive addition of rare earth elements can be solved. 本发明公开一种高强度耐候桥梁钢及其制备工艺，该高强度耐候桥梁钢碳的含量为0.07～0.08wt%,硅的含量为0.24～0.26wt%,锰的含量为1.0～1.2wt%,钙的含量为0.0011～0.0012wt%，铌的含量为0.04～0.05wt%,钛的含量为0.012～0.016wt%,镍的含量为0.33～0.38wt%，铬的含量为0.5～0.6wt%,铜的含量为0.4～0.5wt%,稀土元素的含