The seamless steel pipe is passed through the billet saw section of the steel mill, and then heated in the ring furnace-perforated-sizing-straightened-cooled-saw head-packaged into a qualified finished product. Generally, it cannot be put in the production workshop when it is delivered to the user. With so many stocks, dealers need to place some stocks, but dealers generally do not have large indoor warehouses, and even if there are, the cost is too high and not economical. Most of them are outdoor warehouses, and if the seamless steel pipes are placed outdoors, the wind will inevitably cause the sun.
Floating rust refers to a layer of rust that floats on the seamless steel pipe, which can be removed by a wipe with a towel or other things. Simply put, the floating rust is considered to be free of rust, which is a normal state. The rust of seamless steel pipes is a long time old, at least for more than 1 year, the seamless steel pipes that have been exposed to the wind and the sun have large and small pits on the rusted seamless steel pipes. This is also the biggest difference between floating rust and rust on seamless steel pipes.
Tips: ASTM A53 covers seamless and welded steel pipe with nominal wall thickness. The surface condition is usually black and hot-dipped galvanized. ASTM A53 is produced mainly for pressure and mechanical applications, and is also used for transport of steam, water, gas line pipes.