How to distinguish between seamless steel pipe and heat expanded steel pipe
In the appearance of the steel pipe, the heat expanded is red, and the inner diameter is lead powder.A method of processing thermal expansion steel pipe is to process small-diameter steel pipe into large-diameter steel pipe. The mechanical properties of hot-expanded steel pipes are slightly worse than those of hot-rolled steel pipes.
The heat-expanded steel pipe we often say refers to the steel pipe with relatively low density but strong shrinkage. (Seamless steel pipe) can be referred to as heat-expanded pipe for short. A rough tube finishing rolling process in which the diameter of a pipe is enlarged by a diagonal rolling method or a drawing method. Thickening steel pipes in a short period of time can produce non-standard, special types of seamless pipes, and the cost is low and the production efficiency is high, which is the current development trend in the international pipe rolling field
When welding seamless steel pipes with magnetic, we often see unstable arc combustion, even difficult arc ignition, deviation of the arc in the magnetic field, and molten metal and slag melt splashing from the welding bath. In order to stabilize the welding process and improve the quality of the welded joint, the magnetized steel pipe must be demagnetized before welding. It is difficult to achieve complete demagnetization of the welded steel pipe, so welding is allowed when the residual magnetism is insufficient to affect the welding quality.