Hot rolling and hot expanding are two common processes for Q345B seamless steel pipe. How to distinguish hot rolled and hot expanded Q345B seamless steel pipe? Here is a detailed introduction:

Generally speaking, both hot rolled and hot expanded seamless steel pipe have strict requirements for the steel material used in the steel pipe manufacturing. The hot expanded steel pipe is only a kind of steel pipe manufacturing process, which is to process the small-diameter steel pipe into the large-diameter steel pipe.

Hot expanded steel pipe: first of all, on the appearance of the Q345B seamless steel pipe, the hot expanded steel pipe is red, and the inside of the inner diameter is lead pink.

The steel pipes to be hot-expanded have strict requirements on the quality of steel grades. Usually, steel pipes with strong shrinkage properties such as Q345B seamless steel pipe are used, and a waste pipe finish rolling process is used to expand the diameter of the pipe by cross-rolling or drawing. In this way, the steel pipe is thickened in a relatively short time and used to produce non-standard and special hot-rolled pipes. This kind of hot-expanded steel pipe has low cost and high production efficiency. However, the mechanical properties of hot expanded Q345B seamless steel pipe are slightly worse than that of the hot rolled Q345B seamless steel pipe.

Because of its reasonable process, low energy consumption and good quality, hot expanded Q345B seamless steel pipe is more and more recognized by everyone. Due to the high cost of producing large diameter hot rolled Q345B seamless steel pipe, it is basically purchased for important parts.