Large-diameter seamless steel pipe, the main production process is hot-rolled large-diameter seamless steel pipe and hot-expanded caliber seamless steel pipe, a steel pipe with a relatively low density but strong shrinkage that expands the diameter of the pipe by cross-rolling or drawing. Finishing process. It is a development trend in the international pipe rolling field to increase the thickness of the steel pipe in a relatively short period of time, with low cost and high production efficiency.
Due to their different manufacturing processes, seamless steel pipes are divided into two types: hot-rolled (extruded) seamless steel pipes and cold-drawn (rolled) seamless steel pipes. Cold drawn (rolled) tubes are divided into two types: round tubes and special-shaped tubes.

Delivery status of large diameter seamless steel pipe

Large-diameter seamless steel pipes are cold-drawn, cold-rolled and other cold-formed steel, and the state of direct delivery without any heat treatment is called cold-drawn or cold-rolled state.
After hot rolling or forging, large-diameter seamless steel pipes are no longer subject to special heat treatment, and are delivered directly after cooling, which is called hot rolling or hot forging.
Large-diameter seamless steel pipes are annealed and heat-treated before leaving the factory. This delivery state is called the annealed state.

The formula for calculating the weight of large-diameter seamless steel pipes:

[(outer diameter-wall thickness)*wall thickness]*0.02466 = kg/m (weight per meter)

General specifications of large diameter seamless steel pipe:

The outer diameter between (89mm-1200mm) is called large diameter seamless pipe.
Wall thickness (5mm-200mm) is divided into: large diameter thick wall seamless pipe, large diameter thin wall seamless pipe.