Welded steel pipes are not treated as black ones.


Welded steel pipes are formed by bending steel or steel plates into circular or square shapes, and then welded to the surface of the joints with steel pipes. The billet used in welded steel pipe is steel or strip.


In the environment containing sulfuric acid or hydrochloric acid, the higher the content of Ni in T-shaped welded steel pipe, the stronger the corrosion resistance.  In general environment, only adding Cr into T-type welded steel pipe can prevent corrosion. Poor band edges are another important cause of errors. The effects of mass flow, heat flow and structural parameters (the ratio of helical curvature diameter to polygonal welded pipe diameter Dc/D) on the boiling heat transfer coefficient of saturated bubbles in vertical helical tubes.


In the production of T-type welded steel pipe, there are many factors affecting the wrong side. In production practice, steel pipe is often dried.