Q345A welded steel pipes is a low-carbon alloy steel (c <0.2%) which under GB/T 3091-2008 standard, Q345A welded steel pipes have comprehensive performance, low temperature performance, cold stamping performance, welding performance and cutting performance. Widely used in bridges, vehicles, ships, construction, pressure vessels, the surface can be painted black paint, varnish, rust oil, hot dip galvanized, cold galvanized, 3PE and so on.